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path: root/drivers/rtc/rtc-cmos.c
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2023-12-17rtc: Extend timeout for waiting for UIP to clear to 1sMario Limonciello
Specs don't say anything about UIP being cleared within 10ms. They only say that UIP won't occur for another 244uS. If a long NMI occurs while UIP is still updating it might not be possible to get valid data in 10ms. This has been observed in the wild that around s2idle some calls can take up to 480ms before UIP is clear. Adjust callers from outside an interrupt context to wait for up to a 1s instead of 10ms. Cc: <stable@vger.kernel.org> # 6.1.y Fixes: ec5895c0f2d8 ("rtc: mc146818-lib: extract mc146818_avoid_UIP") Reported-by: Carsten Hatger <xmb8dsv4@gmail.com> Closes: https://bugzilla.kernel.org/show_bug.cgi?id=217626 Tested-by: Mateusz Jończyk <mat.jonczyk@o2.pl> Reviewed-by: Mateusz Jończyk <mat.jonczyk@o2.pl> Acked-by: Mateusz Jończyk <mat.jonczyk@o2.pl> Signed-off-by: Mario Limonciello <mario.limonciello@amd.com> Link: https://lore.kernel.org/r/20231128053653.101798-5-mario.limonciello@amd.com Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2023-12-17rtc: Add support for configuring the UIP timeout for RTC readsMario Limonciello
The UIP timeout is hardcoded to 10ms for all RTC reads, but in some contexts this might not be enough time. Add a timeout parameter to mc146818_get_time() and mc146818_get_time_callback(). If UIP timeout is configured by caller to be >=100 ms and a call takes this long, log a warning. Make all callers use 10ms to ensure no functional changes. Cc: <stable@vger.kernel.org> # 6.1.y Fixes: ec5895c0f2d8 ("rtc: mc146818-lib: extract mc146818_avoid_UIP") Signed-off-by: Mario Limonciello <mario.limonciello@amd.com> Tested-by: Mateusz Jończyk <mat.jonczyk@o2.pl> Reviewed-by: Mateusz Jończyk <mat.jonczyk@o2.pl> Acked-by: Mateusz Jończyk <mat.jonczyk@o2.pl> Link: https://lore.kernel.org/r/20231128053653.101798-4-mario.limonciello@amd.com Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2023-12-17rtc: Adjust failure return code for cmos_set_alarm()Mario Limonciello
When mc146818_avoid_UIP() fails to return a valid value, this is because UIP didn't clear in the timeout period. Adjust the return code in this case to -ETIMEDOUT. Tested-by: Mateusz Jończyk <mat.jonczyk@o2.pl> Reviewed-by: Mateusz Jończyk <mat.jonczyk@o2.pl> Acked-by: Mateusz Jończyk <mat.jonczyk@o2.pl> Cc: <stable@vger.kernel.org> Fixes: cdedc45c579f ("rtc: cmos: avoid UIP when reading alarm time") Fixes: cd17420ebea5 ("rtc: cmos: avoid UIP when writing alarm time") Signed-off-by: Mario Limonciello <mario.limonciello@amd.com> Link: https://lore.kernel.org/r/20231128053653.101798-3-mario.limonciello@amd.com Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2023-11-17rtc: cmos: Use ACPI alarm for non-Intel x86 systems tooMario Limonciello
Intel systems > 2015 have been configured to use ACPI alarm instead of HPET to avoid s2idle issues. Having HPET programmed for wakeup causes problems on AMD systems with s2idle as well. One particular case is that the systemd "SuspendThenHibernate" feature doesn't work properly on the Framework 13" AMD model. Switching to using ACPI alarm fixes the issue. Adjust the quirk to apply to AMD/Hygon systems from 2021 onwards. This matches what has been tested and is specifically to avoid potential risk to older systems. Cc: <stable@vger.kernel.org> # 6.1+ Reported-by: <alvin.zhuge@gmail.com> Reported-by: <renzhamin@gmail.com> Closes: https://github.com/systemd/systemd/issues/24279 Reported-by: Kelvie Wong <kelvie@kelvie.ca> Closes: https://community.frame.work/t/systemd-suspend-then-hibernate-wakes-up-after-5-minutes/39392 Signed-off-by: Mario Limonciello <mario.limonciello@amd.com> Link: https://lore.kernel.org/r/20231106162310.85711-1-mario.limonciello@amd.com Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2023-08-27rtc: cmos: Report supported alarm limit to rtc infrastructureGuenter Roeck
The alarm window supported by the cmos RTC depends on the chip and its configuration. Report the limit to the RTC core. Cc: Brian Norris <briannorris@chromium.org> Signed-off-by: Guenter Roeck <linux@roeck-us.net> Link: https://lore.kernel.org/r/20230817225537.4053865-5-linux@roeck-us.net Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2023-03-17rtc: cmos: Convert to platform remove callback returning voidUwe Kleine-König
The .remove() callback for a platform driver returns an int which makes many driver authors wrongly assume it's possible to do error handling by returning an error code. However the value returned is (mostly) ignored and this typically results in resource leaks. To improve here there is a quest to make the remove callback return void. In the first step of this quest all drivers are converted to .remove_new() which already returns void. Trivially convert this driver from always returning zero in the remove callback to the void returning variant. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Link: https://lore.kernel.org/r/20230304133028.2135435-10-u.kleine-koenig@pengutronix.de Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2022-11-15rtc: cmos: Disable ACPI RTC event on removalRafael J. Wysocki
Make cmos_do_remove() drop the ACPI RTC fixed event handler so as to prevent it from operating on stale data in case the event triggers after driver removal. Fixes: 311ee9c151ad ("rtc: cmos: allow using ACPI for RTC alarm instead of HPET") Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-by: Zhang Rui <rui.zhang@intel.com> Tested-by: Zhang Rui <rui.zhang@intel.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/2224609.iZASKD2KPV@kreacher Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2022-11-15rtc: cmos: Rename ACPI-related functionsRafael J. Wysocki
The names of rtc_wake_setup() and cmos_wake_setup() don't indicate that these functions are ACPI-related, which is the case, and the former doesn't really reflect the role of the function. Rename them to acpi_rtc_event_setup() and acpi_cmos_wake_setup(), respectively, to address this shortcoming. No intentional functional impact. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-by: Zhang Rui <rui.zhang@intel.com> Tested-by: Zhang Rui <rui.zhang@intel.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/3225614.44csPzL39Z@kreacher Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2022-11-15rtc: cmos: Eliminate forward declarations of some functionsRafael J. Wysocki
Reorder the ACPI-related code before cmos_do_probe() so as to eliminate excessive forward declarations of some functions. While at it, for consistency, add the inline modifier to the definitions of empty stub static funtions and remove it from the corresponding definitions of functions with non-empty bodies. No intentional functional impact. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-by: Zhang Rui <rui.zhang@intel.com> Tested-by: Zhang Rui <rui.zhang@intel.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/13157911.uLZWGnKmhe@kreacher Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2022-11-15rtc: cmos: Call rtc_wake_setup() from cmos_do_probe()Rafael J. Wysocki
To reduce code duplication, move the invocation of rtc_wake_setup() into cmos_do_probe() and simplify the callers of the latter. No intentional functional impact. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-by: Zhang Rui <rui.zhang@intel.com> Tested-by: Zhang Rui <rui.zhang@intel.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/2143522.irdbgypaU6@kreacher Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2022-11-15rtc: cmos: Call cmos_wake_setup() from cmos_do_probe()Rafael J. Wysocki
Notice that cmos_wake_setup() is the only user of acpi_rtc_info and it can operate on the cmos_rtc variable directly, so it need not set the platform_data pointer before cmos_do_probe() is called. Instead, it can be called by cmos_do_probe() in the case when the platform_data pointer is not set to implement the default behavior (which is to use the FADT information as long as ACPI support is enabled). Modify the code accordingly. While at it, drop a comment that doesn't really match the code it is supposed to be describing. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-by: Zhang Rui <rui.zhang@intel.com> Tested-by: Zhang Rui <rui.zhang@intel.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/4803444.31r3eYUQgx@kreacher Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2022-10-18rtc: cmos: fix build on non-ACPI platformsAlexandre Belloni
Now that rtc_wake_setup is called outside of cmos_wake_setup, it also need to be defined on non-ACPI platforms. Reported-by: kernel test robot <lkp@intel.com> Link: https://lore.kernel.org/r/20221018203512.2532407-1-alexandre.belloni@bootlin.com Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2022-10-18rtc: cmos: Fix wake alarm breakageRafael J. Wysocki
Commit 4919d3eb2ec0 ("rtc: cmos: Fix event handler registration ordering issue") overlooked the fact that cmos_do_probe() depended on the preparations carried out by cmos_wake_setup() and the wake alarm stopped working after the ordering of them had been changed. Address this by partially reverting commit 4919d3eb2ec0 so that cmos_wake_setup() is called before cmos_do_probe() again and moving the rtc_wake_setup() invocation from cmos_wake_setup() directly to the callers of cmos_do_probe() where it will happen after a successful completion of the latter. Fixes: 4919d3eb2ec0 ("rtc: cmos: Fix event handler registration ordering issue") Reported-by: Zhang Rui <rui.zhang@intel.com> Reported-by: Todd Brandt <todd.e.brandt@linux.intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Link: https://lore.kernel.org/r/5887691.lOV4Wx5bFT@kreacher Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2022-10-13rtc: cmos: Fix event handler registration ordering issueRafael J. Wysocki
Because acpi_install_fixed_event_handler() enables the event automatically on success, it is incorrect to call it before the handler routine passed to it is ready to handle events. Unfortunately, the rtc-cmos driver does exactly the incorrect thing by calling cmos_wake_setup(), which passes rtc_handler() to acpi_install_fixed_event_handler(), before cmos_do_probe(), because rtc_handler() uses dev_get_drvdata() to get to the cmos object pointer and the driver data pointer is only populated in cmos_do_probe(). This leads to a NULL pointer dereference in rtc_handler() on boot if the RTC fixed event happens to be active at the init time. To address this issue, change the initialization ordering of the driver so that cmos_wake_setup() is always called after a successful cmos_do_probe() call. While at it, change cmos_pnp_probe() to call cmos_do_probe() after the initial if () statement used for computing the IRQ argument to be passed to cmos_do_probe() which is cleaner than calling it in each branch of that if () (local variable "irq" can be of type int, because it is passed to that function as an argument of type int). Note that commit 6492fed7d8c9 ("rtc: rtc-cmos: Do not check ACPI_FADT_LOW_POWER_S0") caused this issue to affect a larger number of systems, because previously it only affected systems with ACPI_FADT_LOW_POWER_S0 set, but it is present regardless of that commit. Fixes: 6492fed7d8c9 ("rtc: rtc-cmos: Do not check ACPI_FADT_LOW_POWER_S0") Fixes: a474aaedac99 ("rtc-cmos: move wake setup from ACPI glue into RTC driver") Link: https://lore.kernel.org/linux-acpi/20221010141630.zfzi7mk7zvnmclzy@techsingularity.net/ Reported-by: Mel Gorman <mgorman@techsingularity.net> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-by: Bjorn Helgaas <bhelgaas@google.com> Tested-by: Mel Gorman <mgorman@techsingularity.net> Link: https://lore.kernel.org/r/5629262.DvuYhMxLoT@kreacher Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2022-08-08rtc: rtc-cmos: Do not check ACPI_FADT_LOW_POWER_S0Rafael J. Wysocki
The ACPI_FADT_LOW_POWER_S0 flag merely means that it is better to use low-power S0 idle on the given platform than S3 (provided that the latter is supported) and it doesn't preclude using either of them (which of them will be used depends on the choices made by user space). For this reason, there is no benefit from checking that flag in use_acpi_alarm_quirks(). First off, it cannot be a bug to do S3 with use_acpi_alarm set, because S3 can be used on systems with ACPI_FADT_LOW_POWER_S0 and it must work if really supported, so the ACPI_FADT_LOW_POWER_S0 check is not needed to protect the S3-capable systems from failing. Second, suspend-to-idle can be carried out on a system with ACPI_FADT_LOW_POWER_S0 unset and it is expected to work, so if setting use_acpi_alarm is needed to handle that case correctly, it should be set regardless of the ACPI_FADT_LOW_POWER_S0 value. Accordingly, drop the ACPI_FADT_LOW_POWER_S0 check from use_acpi_alarm_quirks(). Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-by: Mario Limonciello <mario.limonciello@amd.com> Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Link: https://lore.kernel.org/r/12054246.O9o76ZdvQC@kreacher
2021-12-16rtc: cmos: avoid UIP when writing alarm timeMateusz Jończyk
Some Intel chipsets disconnect the time and date RTC registers when the clock update is in progress: during this time reads may return bogus values and writes fail silently. This includes the RTC alarm registers. [1] cmos_set_alarm() did not take account for that, fix it. [1] 7th Generation Intel ® Processor Family I/O for U/Y Platforms [...] Datasheet, Volume 1 of 2 (Intel's Document Number: 334658-006) Page 208 https://www.intel.com/content/dam/www/public/us/en/documents/datasheets/7th-and-8th-gen-core-family-mobile-u-y-processor-lines-i-o-datasheet-vol-1.pdf "If a RAM read from the ten time and date bytes is attempted during an update cycle, the value read do not necessarily represent the true contents of those locations. Any RAM writes under the same conditions are ignored." Signed-off-by: Mateusz Jończyk <mat.jonczyk@o2.pl> Cc: Alessandro Zummo <a.zummo@towertech.it> Cc: Alexandre Belloni <alexandre.belloni@bootlin.com> Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Link: https://lore.kernel.org/r/20211210200131.153887-10-mat.jonczyk@o2.pl
2021-12-16rtc: cmos: avoid UIP when reading alarm timeMateusz Jończyk
Some Intel chipsets disconnect the time and date RTC registers when the clock update is in progress: during this time reads may return bogus values and writes fail silently. This includes the RTC alarm registers. [1] cmos_read_alarm() did not take account for that, which caused alarm time reads to sometimes return bogus values. This can be shown with a test patch that I am attaching to this patch series. Fix this, by using mc146818_avoid_UIP(). [1] 7th Generation Intel ® Processor Family I/O for U/Y Platforms [...] Datasheet, Volume 1 of 2 (Intel's Document Number: 334658-006) Page 208 https://www.intel.com/content/dam/www/public/us/en/documents/datasheets/7th-and-8th-gen-core-family-mobile-u-y-processor-lines-i-o-datasheet-vol-1.pdf "If a RAM read from the ten time and date bytes is attempted during an update cycle, the value read do not necessarily represent the true contents of those locations. Any RAM writes under the same conditions are ignored." Signed-off-by: Mateusz Jończyk <mat.jonczyk@o2.pl> Cc: Alessandro Zummo <a.zummo@towertech.it> Cc: Alexandre Belloni <alexandre.belloni@bootlin.com> Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Link: https://lore.kernel.org/r/20211210200131.153887-9-mat.jonczyk@o2.pl
2021-12-16rtc: mc146818-lib: fix RTC presence checkMateusz Jończyk
To prevent an infinite loop in mc146818_get_time(), commit 211e5db19d15 ("rtc: mc146818: Detect and handle broken RTCs") added a check for RTC availability. Together with a later fix, it checked if bit 6 in register 0x0d is cleared. This, however, caused a false negative on a motherboard with an AMD SB710 southbridge; according to the specification [1], bit 6 of register 0x0d of this chipset is a scratchbit. This caused a regression in Linux 5.11 - the RTC was determined broken by the kernel and not used by rtc-cmos.c [3]. This problem was also reported in Fedora [4]. As a better alternative, check whether the UIP ("Update-in-progress") bit is set for longer then 10ms. If that is the case, then apparently the RTC is either absent (and all register reads return 0xff) or broken. Also limit the number of loop iterations in mc146818_get_time() to 10 to prevent an infinite loop there. The functions mc146818_get_time() and mc146818_does_rtc_work() will be refactored later in this patch series, in order to fix a separate problem with reading / setting the RTC alarm time. This is done so to avoid a confusion about what is being fixed when. In a previous approach to this problem, I implemented a check whether the RTC_HOURS register contains a value <= 24. This, however, sometimes did not work correctly on my Intel Kaby Lake laptop. According to Intel's documentation [2], "the time and date RAM locations (0-9) are disconnected from the external bus" during the update cycle so reading this register without checking the UIP bit is incorrect. [1] AMD SB700/710/750 Register Reference Guide, page 308, https://developer.amd.com/wordpress/media/2012/10/43009_sb7xx_rrg_pub_1.00.pdf [2] 7th Generation Intel ® Processor Family I/O for U/Y Platforms [...] Datasheet Volume 1 of 2, page 209 Intel's Document Number: 334658-006, https://www.intel.com/content/dam/www/public/us/en/documents/datasheets/7th-and-8th-gen-core-family-mobile-u-y-processor-lines-i-o-datasheet-vol-1.pdf [3] Functions in arch/x86/kernel/rtc.c apparently were using it. [4] https://bugzilla.redhat.com/show_bug.cgi?id=1936688 Fixes: 211e5db19d15 ("rtc: mc146818: Detect and handle broken RTCs") Fixes: ebb22a059436 ("rtc: mc146818: Dont test for bit 0-5 in Register D") Signed-off-by: Mateusz Jończyk <mat.jonczyk@o2.pl> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Alessandro Zummo <a.zummo@towertech.it> Cc: Alexandre Belloni <alexandre.belloni@bootlin.com> Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Link: https://lore.kernel.org/r/20211210200131.153887-5-mat.jonczyk@o2.pl
2021-12-16rtc: Check return value from mc146818_get_time()Mateusz Jończyk
There are 4 users of mc146818_get_time() and none of them was checking the return value from this function. Change this. Print the appropriate warnings in callers of mc146818_get_time() instead of in the function mc146818_get_time() itself, in order not to add strings to rtc-mc146818-lib.c, which is kind of a library. The callers of alpha_rtc_read_time() and cmos_read_time() may use the contents of (struct rtc_time *) even when the functions return a failure code. Therefore, set the contents of (struct rtc_time *) to 0x00, which looks more sensible then 0xff and aligns with the (possibly stale?) comment in cmos_read_time: /* * If pm_trace abused the RTC for storage, set the timespec to 0, * which tells the caller that this RTC value is unusable. */ For consistency, do this in mc146818_get_time(). Note: hpet_rtc_interrupt() may call mc146818_get_time() many times a second. It is very unlikely, though, that the RTC suddenly stops working and mc146818_get_time() would consistently fail. Only compile-tested on alpha. Signed-off-by: Mateusz Jończyk <mat.jonczyk@o2.pl> Cc: Richard Henderson <rth@twiddle.net> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Matt Turner <mattst88@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Alessandro Zummo <a.zummo@towertech.it> Cc: Alexandre Belloni <alexandre.belloni@bootlin.com> Cc: linux-alpha@vger.kernel.org Cc: x86@kernel.org Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Link: https://lore.kernel.org/r/20211210200131.153887-4-mat.jonczyk@o2.pl
2021-12-16rtc: cmos: take rtc_lock while reading from CMOSMateusz Jończyk
Reading from the CMOS involves writing to the index register and then reading from the data register. Therefore access to the CMOS has to be serialized with rtc_lock. This invocation of CMOS_READ was not serialized, which could cause trouble when other code is accessing CMOS at the same time. Use spin_lock_irq() like the rest of the function. Nothing in kernel modifies the RTC_DM_BINARY bit, so there could be a separate pair of spin_lock_irq() / spin_unlock_irq() before doing the math. Signed-off-by: Mateusz Jończyk <mat.jonczyk@o2.pl> Reviewed-by: Nobuhiro Iwamatsu <iwamatsu@nigauri.org> Cc: Alessandro Zummo <a.zummo@towertech.it> Cc: Alexandre Belloni <alexandre.belloni@bootlin.com> Cc: stable@vger.kernel.org Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Link: https://lore.kernel.org/r/20211210200131.153887-2-mat.jonczyk@o2.pl
2021-09-14rtc: cmos: Disable irq around direct invocation of cmos_interrupt()Chris Wilson
As previously noted in commit 66e4f4a9cc38 ("rtc: cmos: Use spin_lock_irqsave() in cmos_interrupt()"): <4>[ 254.192378] WARNING: inconsistent lock state <4>[ 254.192384] 5.12.0-rc1-CI-CI_DRM_9834+ #1 Not tainted <4>[ 254.192396] -------------------------------- <4>[ 254.192400] inconsistent {IN-HARDIRQ-W} -> {HARDIRQ-ON-W} usage. <4>[ 254.192409] rtcwake/5309 [HC0[0]:SC0[0]:HE1:SE1] takes: <4>[ 254.192429] ffffffff8263c5f8 (rtc_lock){?...}-{2:2}, at: cmos_interrupt+0x18/0x100 <4>[ 254.192481] {IN-HARDIRQ-W} state was registered at: <4>[ 254.192488] lock_acquire+0xd1/0x3d0 <4>[ 254.192504] _raw_spin_lock+0x2a/0x40 <4>[ 254.192519] cmos_interrupt+0x18/0x100 <4>[ 254.192536] rtc_handler+0x1f/0xc0 <4>[ 254.192553] acpi_ev_fixed_event_detect+0x109/0x13c <4>[ 254.192574] acpi_ev_sci_xrupt_handler+0xb/0x28 <4>[ 254.192596] acpi_irq+0x13/0x30 <4>[ 254.192620] __handle_irq_event_percpu+0x43/0x2c0 <4>[ 254.192641] handle_irq_event_percpu+0x2b/0x70 <4>[ 254.192661] handle_irq_event+0x2f/0x50 <4>[ 254.192680] handle_fasteoi_irq+0x9e/0x150 <4>[ 254.192693] __common_interrupt+0x76/0x140 <4>[ 254.192715] common_interrupt+0x96/0xc0 <4>[ 254.192732] asm_common_interrupt+0x1e/0x40 <4>[ 254.192750] _raw_spin_unlock_irqrestore+0x38/0x60 <4>[ 254.192767] resume_irqs+0xba/0xf0 <4>[ 254.192786] dpm_resume_noirq+0x245/0x3d0 <4>[ 254.192811] suspend_devices_and_enter+0x230/0xaa0 <4>[ 254.192835] pm_suspend.cold.8+0x301/0x34a <4>[ 254.192859] state_store+0x7b/0xe0 <4>[ 254.192879] kernfs_fop_write_iter+0x11d/0x1c0 <4>[ 254.192899] new_sync_write+0x11d/0x1b0 <4>[ 254.192916] vfs_write+0x265/0x390 <4>[ 254.192933] ksys_write+0x5a/0xd0 <4>[ 254.192949] do_syscall_64+0x33/0x80 <4>[ 254.192965] entry_SYSCALL_64_after_hwframe+0x44/0xae <4>[ 254.192986] irq event stamp: 43775 <4>[ 254.192994] hardirqs last enabled at (43775): [<ffffffff81c00c42>] asm_sysvec_apic_timer_interrupt+0x12/0x20 <4>[ 254.193023] hardirqs last disabled at (43774): [<ffffffff81aa691a>] sysvec_apic_timer_interrupt+0xa/0xb0 <4>[ 254.193049] softirqs last enabled at (42548): [<ffffffff81e00342>] __do_softirq+0x342/0x48e <4>[ 254.193074] softirqs last disabled at (42543): [<ffffffff810b45fd>] irq_exit_rcu+0xad/0xd0 <4>[ 254.193101] other info that might help us debug this: <4>[ 254.193107] Possible unsafe locking scenario: <4>[ 254.193112] CPU0 <4>[ 254.193117] ---- <4>[ 254.193121] lock(rtc_lock); <4>[ 254.193137] <Interrupt> <4>[ 254.193142] lock(rtc_lock); <4>[ 254.193156] *** DEADLOCK *** <4>[ 254.193161] 6 locks held by rtcwake/5309: <4>[ 254.193174] #0: ffff888104861430 (sb_writers#5){.+.+}-{0:0}, at: ksys_write+0x5a/0xd0 <4>[ 254.193232] #1: ffff88810f823288 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0xe7/0x1c0 <4>[ 254.193282] #2: ffff888100cef3c0 (kn->active#285 <7>[ 254.192706] i915 0000:00:02.0: [drm:intel_modeset_setup_hw_state [i915]] [CRTC:51:pipe A] hw state readout: disabled <4>[ 254.193307] ){.+.+}-{0:0}, at: kernfs_fop_write_iter+0xf0/0x1c0 <4>[ 254.193333] #3: ffffffff82649fa8 (system_transition_mutex){+.+.}-{3:3}, at: pm_suspend.cold.8+0xce/0x34a <4>[ 254.193387] #4: ffffffff827a2108 (acpi_scan_lock){+.+.}-{3:3}, at: acpi_suspend_begin+0x47/0x70 <4>[ 254.193433] #5: ffff8881019ea178 (&dev->mutex){....}-{3:3}, at: device_resume+0x68/0x1e0 <4>[ 254.193485] stack backtrace: <4>[ 254.193492] CPU: 1 PID: 5309 Comm: rtcwake Not tainted 5.12.0-rc1-CI-CI_DRM_9834+ #1 <4>[ 254.193514] Hardware name: Google Soraka/Soraka, BIOS MrChromebox-4.10 08/25/2019 <4>[ 254.193524] Call Trace: <4>[ 254.193536] dump_stack+0x7f/0xad <4>[ 254.193567] mark_lock.part.47+0x8ca/0xce0 <4>[ 254.193604] __lock_acquire+0x39b/0x2590 <4>[ 254.193626] ? asm_sysvec_apic_timer_interrupt+0x12/0x20 <4>[ 254.193660] lock_acquire+0xd1/0x3d0 <4>[ 254.193677] ? cmos_interrupt+0x18/0x100 <4>[ 254.193716] _raw_spin_lock+0x2a/0x40 <4>[ 254.193735] ? cmos_interrupt+0x18/0x100 <4>[ 254.193758] cmos_interrupt+0x18/0x100 <4>[ 254.193785] cmos_resume+0x2ac/0x2d0 <4>[ 254.193813] ? acpi_pm_set_device_wakeup+0x1f/0x110 <4>[ 254.193842] ? pnp_bus_suspend+0x10/0x10 <4>[ 254.193864] pnp_bus_resume+0x5e/0x90 <4>[ 254.193885] dpm_run_callback+0x5f/0x240 <4>[ 254.193914] device_resume+0xb2/0x1e0 <4>[ 254.193942] ? pm_dev_err+0x25/0x25 <4>[ 254.193974] dpm_resume+0xea/0x3f0 <4>[ 254.194005] dpm_resume_end+0x8/0x10 <4>[ 254.194030] suspend_devices_and_enter+0x29b/0xaa0 <4>[ 254.194066] pm_suspend.cold.8+0x301/0x34a <4>[ 254.194094] state_store+0x7b/0xe0 <4>[ 254.194124] kernfs_fop_write_iter+0x11d/0x1c0 <4>[ 254.194151] new_sync_write+0x11d/0x1b0 <4>[ 254.194183] vfs_write+0x265/0x390 <4>[ 254.194207] ksys_write+0x5a/0xd0 <4>[ 254.194232] do_syscall_64+0x33/0x80 <4>[ 254.194251] entry_SYSCALL_64_after_hwframe+0x44/0xae <4>[ 254.194274] RIP: 0033:0x7f07d79691e7 <4>[ 254.194293] Code: 64 89 02 48 c7 c0 ff ff ff ff eb bb 0f 1f 80 00 00 00 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 51 c3 48 83 ec 28 48 89 54 24 18 48 89 74 24 <4>[ 254.194312] RSP: 002b:00007ffd9cc2c768 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 <4>[ 254.194337] RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 00007f07d79691e7 <4>[ 254.194352] RDX: 0000000000000004 RSI: 0000556ebfc63590 RDI: 000000000000000b <4>[ 254.194366] RBP: 0000556ebfc63590 R08: 0000000000000000 R09: 0000000000000004 <4>[ 254.194379] R10: 0000556ebf0ec2a6 R11: 0000000000000246 R12: 0000000000000004 which breaks S3-resume on fi-kbl-soraka presumably as that's slow enough to trigger the alarm during the suspend. Fixes: 6950d046eb6e ("rtc: cmos: Replace spin_lock_irqsave with spin_lock in hard IRQ") References: 66e4f4a9cc38 ("rtc: cmos: Use spin_lock_irqsave() in cmos_interrupt()"): Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Xiaofei Tan <tanxiaofei@huawei.com> Cc: Alexandre Belloni <alexandre.belloni@bootlin.com> Cc: Alessandro Zummo <a.zummo@towertech.it> Cc: Ville Syrjälä <ville.syrjala@linux.intel.com> Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com> Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Link: https://lore.kernel.org/r/20210305122140.28774-1-chris@chris-wilson.co.uk
2021-08-17rtc: cmos: remove stale REVISIT commentsMateusz Jończyk
It appears mc146818_get_time() and mc146818_set_time() now correctly use the century register as specified in the ACPI FADT table. It is not clear what else could be done here. These comments were introduced by commit 7be2c7c96aff ("[PATCH] RTC framework driver for CMOS RTCs") in 2007, which originally referenced function get_rtc_time() in include/asm-generic/rtc.h . Signed-off-by: Mateusz Jończyk <mat.jonczyk@o2.pl> Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Link: https://lore.kernel.org/r/20210716210437.29622-1-mat.jonczyk@o2.pl
2021-02-22Merge tag 'rtc-5.12' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux Pull RTC updates from Alexandre Belloni: "Many cleanups and a few drivers removal this cycle. Subsystem: - Introduce features bitfield and the first feature: RTC_FEATURE_ALARM Removed drivers: - ab3100 - coh901331 - tx4939 - sirfsoc Drivers: - use rtc_lock and rtc_unlock instead of opencoding - constify all struct rtc_class_ops - quiet maybe-unused variable warning - replace spin_lock_irqsave with spin_lock in hard IRQ - pcf2127: disable Power-On Reset Override and run OTP refresh" * tag 'rtc-5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux: (81 commits) rtc: abx80x: Add utility function for writing configuration key rtc: pcf2127: properly set flag WD_CD for rtc chips(pcf2129, pca2129) rtc: pcf8563: Add NXP PCA8565 compatible rtc: s3c: quiet maybe-unused variable warning rtc: s3c: stop setting bogus time rtc: sd3078: quiet maybe-unused variable warning rtc: s35390a: quiet maybe-unused variable warning rtc: rx8581: quiet maybe-unused variable warning rtc: rx8010: quiet maybe-unused variable warning rtc: rv8803: quiet maybe-unused variable warning rtc: rv3032: quiet maybe-unused variable warning rtc: rv3029: quiet maybe-unused variable warning rtc: rv3028: quiet maybe-unused variable warning rtc: rs5c372: quiet maybe-unused variable warning rtc: pcf85363: quiet maybe-unused variable warning rtc: pcf85063: quiet maybe-unused variable warnings rtc: meson: quiet maybe-unused variable warning rtc: m41t80: quiet maybe-unused variable warning rtc: isl1208: quiet maybe-unused variable warning rtc: ds3232: quiet maybe-unused variable warning ...
2021-02-06rtc: cmos: Replace spin_lock_irqsave with spin_lock in hard IRQXiaofei Tan
It is redundant to do irqsave and irqrestore in hardIRQ context, where it has been in a irq-disabled context. Signed-off-by: Xiaofei Tan <tanxiaofei@huawei.com> Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Link: https://lore.kernel.org/r/1612355981-6764-2-git-send-email-tanxiaofei@huawei.com
2021-02-02rtc: mc146818: Dont test for bit 0-5 in Register DThomas Gleixner
The recent change to validate the RTC turned out to be overly tight. While it cures the problem on the reporters machine it breaks machines with Intel chipsets which use bit 0-5 of the D register. So check only for bit 6 being 0 which is the case on these Intel machines as well. Fixes: 211e5db19d15 ("rtc: mc146818: Detect and handle broken RTCs") Reported-by: Serge Belyshev <belyshev@depni.sinp.msu.ru> Reported-by: Dirk Gouders <dirk@gouders.net> Reported-by: Borislav Petkov <bp@suse.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Dirk Gouders <dirk@gouders.net> Tested-by: Len Brown <len.brown@intel.com> Tested-by: Borislav Petkov <bp@suse.de> Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Link: https://lore.kernel.org/r/87zh0nbnha.fsf@nanos.tec.linutronix.de
2021-01-27rtc: mc146818: Detect and handle broken RTCsThomas Gleixner
The recent fix for handling the UIP bit unearthed another issue in the RTC code. If the RTC is advertised but the readout is straight 0xFF because it's not available, the old code just proceeded with crappy values, but the new code hangs because it waits for the UIP bit to become low. Add a sanity check in the RTC CMOS probe function which reads the RTC_VALID register (Register D) which should have bit 0-6 cleared. If that's not the case then fail to register the CMOS. Add the same check to mc146818_get_time(), warn once when the condition is true and invalidate the rtc_time data. Reported-by: Mickaël Salaün <mic@digikod.net> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Mickaël Salaün <mic@linux.microsoft.com> Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Link: https://lore.kernel.org/r/87tur3fx7w.fsf@nanos.tec.linutronix.de
2021-01-16rtc: cmos: remove cmos_rtc_ops_no_alarmAlexandre Belloni
Clear RTC_FEATURE_ALARM to signal that alarms are not available instead of having a supplementary struct rtc_class_ops with a NULL .set_alarm. Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Link: https://lore.kernel.org/r/20210110231752.1418816-5-alexandre.belloni@bootlin.com
2020-12-20Merge tag 'rtc-5.11' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux Pull RTC updates from Alexandre Belloni: "Subsystem: - Remove nvram ABI. There was no complaints about the deprecation for the last 3 years. - Improve RTC device allocation and registration - Now available for ARCH=um Drivers: - at91rm9200: correction and sam9x60 support - ds1307: improve ACPI support - mxc: now DT only - pcf2127: watchdog support now needs the reset-source property - pcf8523: set range - rx6110: i2c support" * tag 'rtc-5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux: (43 commits) rtc: pcf2127: only use watchdog when explicitly available dt-bindings: rtc: add reset-source property rtc: fix RTC removal rtc: s3c: Remove dead code related to periodic tick handling rtc: s3c: Disable all enable (RTC, tick) bits in the probe rtc: ep93xx: Fix NULL pointer dereference in ep93xx_rtc_read_time rtc: test: remove debug message rtc: mxc{,_v2}: enable COMPILE_TEST rtc: enable RTC framework on ARCH=um rtc: pcf8523: use BIT rtc: pcf8523: set range rtc: pcf8523: switch to devm_rtc_allocate_device rtc: destroy mutex when releasing the device rtc: shrink devm_rtc_allocate_device() rtc: rework rtc_register_device() resource management rtc: nvmem: emit an error message when nvmem registration fails rtc: add devm_ prefix to rtc_nvmem_register() rtc: nvmem: remove nvram ABI Documentation: list RTC devres helpers in devres.rst rtc: omap: use devm_pinctrl_register() ...
2020-12-11ntp: Make the RTC sync offset less obscureThomas Gleixner
The current RTC set_offset_nsec value is not really intuitive to understand. tsched twrite(t2.tv_sec - 1) t2 (seconds increment) The offset is calculated from twrite based on the assumption that t2 - twrite == 1s. That means for the MC146818 RTC the offset needs to be negative so that the write happens 500ms before t2. It's easier to understand when the whole calculation is based on t2. That avoids negative offsets and the meaning is obvious: t2 - twrite: The time defined by the chip when seconds increment after the write. twrite - tsched: The time for the transport to the point where the chip is updated. ==> set_offset_nsec = t2 - tsched ttransport = twrite - tsched tRTCinc = t2 - twrite ==> set_offset_nsec = ttransport + tRTCinc tRTCinc is a chip property and can be obtained from the data sheet. ttransport depends on how the RTC is connected. It is close to 0 for directly accessible RTCs. For RTCs behind a slow bus, e.g. i2c, it's the time required to send the update over the bus. This can be estimated or even calibrated, but that's a different problem. Adjust the implementation and update comments accordingly. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Link: https://lore.kernel.org/r/20201206220542.263204937@linutronix.de
2020-12-11rtc: cmos: Make rtc_cmos sync offset correctThomas Gleixner
The offset for rtc_cmos must be -500ms to work correctly with the current implementation of rtc_set_ntp_time() due to the following: tsched twrite(t2.tv_sec - 1) t2 (seconds increment) twrite - tsched is the transport time for the write to hit the device, which is negligible for this chip because it's accessed directly. t2 - twrite = 500ms according to the datasheet. But rtc_set_ntp_time() calculation of tsched is: tsched = t2 - 1sec - (t2 - twrite) The default for the sync offset is 500ms which means that the write happens at t2 - 1.5 seconds which is obviously off by a second for this device. Make the offset -500ms so it works correct. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Link: https://lore.kernel.org/r/20201206220541.830517160@linutronix.de
2020-11-19rtc: rework rtc_register_device() resource managementBartosz Golaszewski
rtc_register_device() is a managed interface but it doesn't use devres by itself - instead it marks an rtc_device as "registered" and the devres callback for devm_rtc_allocate_device() takes care of resource release. This doesn't correspond with the design behind devres where managed structures should not be aware of being managed. The correct solution here is to register a separate devres callback for unregistering the device. While at it: rename rtc_register_device() to devm_rtc_register_device() and add it to the list of managed interfaces in devres.rst. This way we can avoid any potential confusion of driver developers who may expect there to exist a corresponding unregister function. Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com> Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Link: https://lore.kernel.org/r/20201109163409.24301-8-brgl@bgdev.pl
2020-11-19rtc: nvmem: emit an error message when nvmem registration failsBartosz Golaszewski
Some users check the return value of devm_rtc_nvmem_register() only in order to emit an error message and then continue probing. This is fine as an rtc can function without exposing nvmem but let's generalize it: let's make the registration function emit the error message so that users don't have to. Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com> Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Link: https://lore.kernel.org/r/20201109163409.24301-7-brgl@bgdev.pl
2020-11-19rtc: add devm_ prefix to rtc_nvmem_register()Bartosz Golaszewski
rtc_nvmem_register() is a managed interface. It doesn't require any release function to be called at driver detach. To avoid confusing driver authors, let's rename it to devm_rtc_nvmem_register() and add it to the list of managed interfaces in Documentation/. Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com> Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Link: https://lore.kernel.org/r/20201109163409.24301-6-brgl@bgdev.pl
2020-11-19rtc: nvmem: remove nvram ABIAlexandre Belloni
The nvram sysfs attributes have been deprecated at least since v4.13, more than 3 years ago and nobody ever complained about the deprecation warning. Remove the sysfs attributes now. [Bartosz: remove the declaration of rtc_nvmem_unregister()] Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com> Link: https://lore.kernel.org/r/20201109163409.24301-5-brgl@bgdev.pl
2020-08-21rtc: cmos: zero-init wkalrm when reading from CMOSVictor Ding
cmos_read_alarm() may leave certain fields of a struct rtc_wkalrm untouched; therefore, these fields contain garbage if not properly initialized, leading to inconsistent values when converting into time64_t. This patch to zero initialize the struct before calling cmos_read_alarm(). Note that this patch is not intended to produce a correct time64_t, it is only to produce a consistent value. In the case of suspend/resume, a correct time64_t is not necessary; a consistent value is sufficient to correctly perform an equality test for t_current_expires and t_saved_expires. Logic to deduce a correct time64_t is expensive and hence should be avoided. Signed-off-by: Victor Ding <victording@google.com> Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Link: https://lore.kernel.org/r/20200814191654.v2.1.Iaf7638a2f2a87ff68d85fcb8dec615e41340c97f@changeid
2020-04-04Merge tag 'rtc-5.7' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux Pull RTC updates from Alexandre Belloni: "More cleanup this cycle, with the final goal of removing the rtc_time_to_tm and rtc_tm_to_time wrappers. All the drivers that have been modified for this now are ready for the end of times (whether it happens in 2033, 2038, 2106, 2127 or even 4052). There is also a single new driver and the usual fixes and features. Summary: Subsystem: - The rtc_time_to_tm and rtc_tm_to_time wrappers have finally been removed and only the 64bit version remain. - hctosys now works with drivers compiled as modules New driver: - MediaTek MT2712 SoC based RTC Drivers: - set range for 88pm860x, au1xxx, cpcap, da9052, davinci, ds1305, ds1374, mcp5121, pl030, pl031, pm8xxx, puv3, sa1100, sirfsoc, starfire, sun6i - ds1307: DS1388 oscillator failure detection and watchdog support - jz4740: JZ4760 support - pcf85063: clock out pin support - sun6i: external 32k oscillator is now optional, the range is now handled by the core, providing a solution for 2034" * tag 'rtc-5.7' of git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux: (87 commits) rtc: ds1307: check for failed memory allocation on wdt rtc: class: remove redundant assignment to variable err rtc: remove rtc_time_to_tm and rtc_tm_to_time rtc: sun6i: let the core handle rtc range rtc: sun6i: switch to rtc_time64_to_tm/rtc_tm_to_time64 rtc: ds1307: add support for watchdog timer on ds1388 rtc: da9052: switch to rtc_time64_to_tm/rtc_tm_to_time64 rtc: da9052: set range rtc: da9052: convert to devm_rtc_allocate_device rtc: imx-sc: Align imx sc msg structs to 4 rtc: fsl-ftm-alarm: report alarm to core rtc: pcf85063: Add pcf85063 clkout control to common clock framework rtc: make definitions in include/uapi/linux/rtc.h actually useful for user space rtc: class: avoid unnecessary lookup in hctosys dt-bindings: rtc: Convert and update jz4740-rtc doc to YAML rtc: jz4740: Rename vendor-specific DT properties rtc: jz4740: Add support for JZ4760 SoC rtc: class: support hctosys from modular RTC drivers rtc: pm8xxx: clear alarm register when alarm is not enabled rtc: omap: drop unused dt-bindings header ...
2020-03-17rtc: cmos: remove useless cast for driver_nameCorentin Labbe
Now the pnp_driver name is "const char *", there are no need to cast driver_name. Signed-off-by: Corentin Labbe <clabbe@baylibre.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-03-03rtc: cmos: Use spin_lock_irqsave() in cmos_interrupt()Ville Syrjälä
cmos_interrupt() isn't always called from hardirq context, so we must use spin_lock_irqsave() & co. ================================ WARNING: inconsistent lock state 5.6.0-rc2-CI-CI_DRM_7981+ #1 Tainted: G U -------------------------------- inconsistent {IN-HARDIRQ-W} -> {HARDIRQ-ON-W} usage. rtcwake/4315 [HC0[0]:SC0[0]:HE1:SE1] takes: ffffffff82635198 (rtc_lock){?...}, at: cmos_interrupt+0x18/0x100 {IN-HARDIRQ-W} state was registered at: lock_acquire+0xa7/0x1c0 _raw_spin_lock+0x2a/0x40 cmos_interrupt+0x18/0x100 rtc_handler+0x75/0xc0 acpi_ev_fixed_event_detect+0xf9/0x132 acpi_ev_sci_xrupt_handler+0xb/0x28 acpi_irq+0x13/0x30 __handle_irq_event_percpu+0x41/0x2c0 handle_irq_event_percpu+0x2b/0x70 handle_irq_event+0x2f/0x50 handle_fasteoi_irq+0x8e/0x150 do_IRQ+0x7e/0x160 ret_from_intr+0x0/0x35 mwait_idle+0x7e/0x200 do_idle+0x1bb/0x260 cpu_startup_entry+0x14/0x20 start_secondary+0x15f/0x1b0 secondary_startup_64+0xa4/0xb0 irq event stamp: 42003 hardirqs last enabled at (42003): [<ffffffff81a36567>] _raw_spin_unlock_irqrestore+0x47/0x60 hardirqs last disabled at (42002): [<ffffffff81a362ed>] _raw_spin_lock_irqsave+0xd/0x50 softirqs last enabled at (41848): [<ffffffff81e00385>] __do_softirq+0x385/0x47f softirqs last disabled at (41841): [<ffffffff810bab3a>] irq_exit+0xba/0xc0 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(rtc_lock); <Interrupt> lock(rtc_lock); *** DEADLOCK *** 6 locks held by rtcwake/4315: #0: ffff888175dc9408 (sb_writers#5){.+.+}, at: vfs_write+0x1a4/0x1d0 #1: ffff88817406ca80 (&of->mutex){+.+.}, at: kernfs_fop_write+0xdd/0x1b0 #2: ffff888179be85e0 (kn->count#236){.+.+}, at: kernfs_fop_write+0xe6/0x1b0 #3: ffffffff82641e00 (system_transition_mutex){+.+.}, at: pm_suspend+0xb3/0x3b0 #4: ffffffff826b3ee0 (acpi_scan_lock){+.+.}, at: acpi_suspend_begin+0x47/0x80 #5: ffff888178fc3960 (&dev->mutex){....}, at: device_resume+0x92/0x1c0 stack backtrace: CPU: 3 PID: 4315 Comm: rtcwake Tainted: G U 5.6.0-rc2-CI-CI_DRM_7981+ #1 Hardware name: Google Soraka/Soraka, BIOS MrChromebox-4.10 08/25/2019 Call Trace: dump_stack+0x71/0x9b mark_lock+0x49a/0x500 ? print_shortest_lock_dependencies+0x200/0x200 __lock_acquire+0x6d4/0x15d0 ? __lock_acquire+0x460/0x15d0 lock_acquire+0xa7/0x1c0 ? cmos_interrupt+0x18/0x100 _raw_spin_lock+0x2a/0x40 ? cmos_interrupt+0x18/0x100 cmos_interrupt+0x18/0x100 cmos_resume+0x1fd/0x290 ? __acpi_pm_set_device_wakeup+0x24/0x100 pnp_bus_resume+0x5e/0x90 ? pnp_bus_suspend+0x10/0x10 dpm_run_callback+0x64/0x280 device_resume+0xd4/0x1c0 ? dpm_watchdog_set+0x60/0x60 dpm_resume+0x106/0x410 ? dpm_resume_early+0x38c/0x3e0 dpm_resume_end+0x8/0x10 suspend_devices_and_enter+0x16f/0xbe0 ? rcu_read_lock_sched_held+0x4d/0x80 pm_suspend+0x344/0x3b0 state_store+0x78/0xe0 kernfs_fop_write+0x112/0x1b0 vfs_write+0xb9/0x1d0 ksys_write+0x9f/0xe0 do_syscall_64+0x4f/0x220 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7ff934307154 Code: 89 02 48 c7 c0 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 8d 05 b1 07 2e 00 8b 00 85 c0 75 13 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 54 f3 c3 66 90 41 54 55 49 89 d4 53 48 89 f5 RSP: 002b:00007ffe2647c168 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 00007ff934307154 RDX: 0000000000000004 RSI: 000055de3ec4e5a0 RDI: 000000000000000a RBP: 000055de3ec4e5a0 R08: 000055de3ec4c5e0 R09: 00007ff9349f3740 R10: 000055de3ec4a010 R11: 0000000000000246 R12: 000055de3ec4c500 R13: 0000000000000004 R14: 00007ff9345df2a0 R15: 00007ff9345de760 Fixes: c6d3a278cc12 ("rtc: cmos: acknowledge ACPI driven wake alarms upon resume") Fixes: 311ee9c151ad ("rtc: cmos: allow using ACPI for RTC alarm instead of HPET") Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com> Link: https://lore.kernel.org/r/20200221144739.11746-1-ville.syrjala@linux.intel.com Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2020-01-25rtc: cmos: Refactor code by using the new dmi_get_bios_year() helperAndy Shevchenko
Refactor code by using the new dmi_get_bios_year() helper instead of open coding its functionality. This also makes logic slightly clearer. No changes intended. Cc: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Tested-by: Guilherme G. Piccoli <gpiccoli@canonical.com> Reviewed-by: Hans de Goede <hdegoede@redhat.com> Link: https://lore.kernel.org/r/20200123131437.28157-3-andriy.shevchenko@linux.intel.com Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2020-01-25rtc: cmos: Use predefined value for RTC IRQ on legacy x86Andy Shevchenko
When legacy devices are present on x86 machine, the RTC IRQ has a dedicated pre-defined value. Use it instead of hard coded number. Cc: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Tested-by: Guilherme G. Piccoli <gpiccoli@canonical.com> Reviewed-by: Hans de Goede <hdegoede@redhat.com> Link: https://lore.kernel.org/r/20200123131437.28157-2-andriy.shevchenko@linux.intel.com Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2020-01-25rtc: cmos: Stop using shared IRQAndy Shevchenko
As reported by Guilherme G. Piccoli: ---8<---8<---8<--- The rtc-cmos interrupt setting was changed in the commit 079062b28fb4 ("rtc: cmos: prevent kernel warning on IRQ flags mismatch") in order to allow shared interrupts; according to that commit's description, some machine got kernel warnings due to the interrupt line being shared between rtc-cmos and other hardware, and rtc-cmos didn't allow IRQ sharing that time. After the aforementioned commit though it was observed a huge increase in lost HPET interrupts in some systems, observed through the following kernel message: [...] hpet1: lost 35 rtc interrupts After investigation, it was narrowed down to the shared interrupts usage when having the kernel option "irqpoll" enabled. In this case, all IRQ handlers are called for non-timer interrupts, if such handlers are setup in shared IRQ lines. The rtc-cmos IRQ handler could be set to hpet_rtc_interrupt(), which will produce the kernel "lost interrupts" message after doing work - lots of readl/writel to HPET registers, which are known to be slow. Although "irqpoll" is not a default kernel option, it's used in some contexts, one being the kdump kernel (which is an already "impaired" kernel usually running with 1 CPU available), so the performance burden could be considerable. Also, the same issue would happen (in a shorter extent though) when using "irqfixup" kernel option. In a quick experiment, a virtual machine with uptime of 2 minutes produced >300 calls to hpet_rtc_interrupt() when "irqpoll" was set, whereas without sharing interrupts this number reduced to 1 interrupt. Machines with more hardware than a VM should generate even more unnecessary HPET interrupts in this scenario. ---8<---8<---8<--- After looking into the rtc-cmos driver history and DSDT table from the Microsoft Surface 3, we may notice that Hans de Goede submitted a correct fix (see dependency below). Thus, we simply revert the culprit commit. Fixes: 079062b28fb4 ("rtc: cmos: prevent kernel warning on IRQ flags mismatch") Depends-on: a1e23a42f1bd ("rtc: cmos: Do not assume irq 8 for rtc when there are no legacy irqs") Reported-by: Guilherme G. Piccoli <gpiccoli@canonical.com> Cc: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Tested-by: Guilherme G. Piccoli <gpiccoli@canonical.com> Reviewed-by: Hans de Goede <hdegoede@redhat.com> Link: https://lore.kernel.org/r/20200123131437.28157-1-andriy.shevchenko@linux.intel.com Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2019-05-30treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152Thomas Gleixner
Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 3029 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-11-07rtc: cmos: Do not export alarm rtc_ops when we do not support alarmsHans de Goede
When there is no IRQ configured for the RTC, the rtc-cmos code does not support alarms, all alarm rtc_ops fail with -EIO / -EINVAL. The rtc-core expects a rtc driver which does not support rtc alarms to not have alarm ops at all. Otherwise the wakealarm sysfs attr will read as empty rather then returning an error, making it impossible for userspace to find out beforehand if alarms are supported. A system without an IRQ for the RTC before this patch: [root@localhost ~]# cat /sys/class/rtc/rtc0/wakealarm [root@localhost ~]# After this patch: [root@localhost ~]# cat /sys/class/rtc/rtc0/wakealarm cat: /sys/class/rtc/rtc0/wakealarm: No such file or directory [root@localhost ~]# This fixes gnome-session + systemd trying to use suspend-then-hibernate, which causes systemd to abort the suspend when writing the RTC alarm fails. BugLink: https://github.com/systemd/systemd/issues/9988 Signed-off-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2018-10-04rtc: cmos: Remove the `use_acpi_alarm' module parameter for !ACPIMaciej W. Rozycki
Fix a problem with commit 311ee9c151ad ("rtc: cmos: allow using ACPI for RTC alarm instead of HPET") defining `use_acpi_alarm' module parameter even for non-ACPI platforms, which ignore it. Wrap the definition into #ifdef CONFIG_ACPI and use a static inline wrapper function, hardcoded to return 0 and consequently optimized away for !ACPI, following the existing pattern with HPET handling functions. Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org> Fixes: 311ee9c151ad ("rtc: cmos: allow using ACPI for RTC alarm instead of HPET") Cc: stable@vger.kernel.org # 4.18+ Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2018-10-04rtc: cmos: Fix non-ACPI undefined reference to `hpet_rtc_interrupt'Maciej W. Rozycki
Fix a commit 311ee9c151ad ("rtc: cmos: allow using ACPI for RTC alarm instead of HPET") `rtc-cmos' regression causing a link error: drivers/rtc/rtc-cmos.o: In function `cmos_platform_probe': rtc-cmos.c:(.init.text+0x33c): undefined reference to `hpet_rtc_interrupt' rtc-cmos.c:(.init.text+0x3f4): undefined reference to `hpet_rtc_interrupt' with non-ACPI platforms using this driver. The cause is the change of the condition guarding the use of `hpet_rtc_interrupt'. Previously it was a call to `is_hpet_enabled'. That function is static inline and has a hardcoded 0 result for non-ACPI platforms, which imply !HPET_EMULATE_RTC. Consequently the compiler optimized the whole block away including the reference to `hpet_rtc_interrupt', which never made it to the link stage. Now the guarding condition is a call to `use_hpet_alarm', which is not static inline and therefore the compiler may not be able to prove that it actually always returns 0 for non-ACPI platforms. Consequently the build breaks with an unsatisfied reference, because `hpet_rtc_interrupt' is nowhere defined at link time. Fix the problem by marking `use_hpet_alarm' inline. As the `inline' keyword serves as an optimization hint rather than a requirement the compiler is still free to choose whether inlining will be beneficial or not for ACPI platforms. Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org> Fixes: 311ee9c151ad ("rtc: cmos: allow using ACPI for RTC alarm instead of HPET") Cc: stable@vger.kernel.org # 4.18+ Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2018-04-19rtc: cmos: introduce quirks to enable use_acpi_alarm modeZhang Rui
Use ACPI for RTC Alarm only for Intel platforms 1. with Low Power S0 support 2. with HPET RTC emulation enabled 3. no earlier than 2015 Note that, during the test, it is found that this patch 1. works in 4.15-rc kernel 2. hangs the platform after suspend-to-idle for 2 or 3 times, in 4.15.0 3. works again in 4.16-rc3 kernel. 4. works in the latest 4.15.12 stable kernel. Thus although this patch breaks 4.15.0 kernel for some unknown reason, still, it is safe for both upstream and backport. Signed-off-by: Zhang Rui <rui.zhang@intel.com> Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2018-04-19rtc: cmos: acknowledge ACPI driven wake alarms upon resumeZhang Rui
Previously, the RTC alarm is acknowledged either by the cmos rtc irq handler, or by the hpet rtc irq handler. When using ACPI RTC Fixed event as the RTC alarm, the RTC alarm is acknowledged by the ACPI RTC event handler, as addressed in the previous patch. But, when resume from suspend-to-ram (ACPI S3), the ACPI SCI is cleared right after resume, thus the ACPI RTC event handler is not invoked at all, results in the RTC Alarm unacknowledged. Handle this by comparing the current time and the RTC Alarm time in the rtc_cmos driver .resume() callback 1. Assume the wakeup event has already been fired if the RTC Alarm time is earlier than/equal to the current time, and ACK the RTC Alarm. 2. Assume the wakeup event has not been fired if the RTC Alarm time is later than current time, and re-arm it if needed. Signed-off-by: Zhang Rui <rui.zhang@intel.com> Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2018-04-19rtc: cmos: allow using ACPI for RTC alarm instead of HPETZhang Rui
It's found that the HPET timer prevents the platform from entering Low Power S0 on some new Intel platforms. This means that 1. users can still use RTC wake Alarm for suspend-to-idle, but the system never enters Low Power S0, which is a waste of power. or 2. if users want to put the system into Low Power S0, they can not use RTC as the wakeup source. To fix this, we need to stop using the HPET timer for wake alarm. But disabling CONFIG_HPET_EMULATE_RTC is not an option because HPET emulates PIT at the same time, and this is needed on some of these platforms. Thus, introduce a new mode (use_acpi_alarm) to the rtc_cmos driver, so that, even with CONFIG_HPET_EMULATE_RTC enabled, it's still possible to use ACPI SCI for RTC Alarm, including UIE/AIE/wkalrm, instead of HPET. Only necessary changes are made for the new "use_acpi_alarm" mode, including 1. drop all the calls to HPET emulation code, including the HPET irq handler for rtc interrupt. 2. enabling/disabling ACPI RTC Fixed event upon RTC UIE/AIE request. 3. acknowledge the RTC Alarm in ACPI RTC Fixed event handler. There is no functional change made in this patch if the new mode is not enabled. Note: this "use_acpi_alarm" mode is made based on the assumption that ACPI RTC Fixed event is reliable both at runtime and during system wakeup. And this has been verified on a couple of platforms I have, including a MS Surface Pro 4 (SKL), a Lenovo Yoga 900 (SKL), and a HP 9360 (KBL). Signed-off-by: Zhang Rui <rui.zhang@intel.com> Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2018-04-10Merge tag 'rtc-4.17' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux Pull RTC updates from Alexandre Belloni: "This contains a few series that have been in preparation for a while and that will help systems with RTCs that will fail in 2038, 2069 or 2100. Subsystem: - Add tracepoints - Rework of the RTC/nvmem API to allow drivers to discard struct nvmem_config after registration - New range API, drivers can now expose the useful range of the RTC - New offset API the core is now able to add an offset to the RTC time, modifying the supported range. - Multiple rtc_time64_to_tm fixes - Handle time_t overflow on 32 bit platforms in the core instead of letting drivers do crazy things. - remove rtc_control API New driver: - Intersil ISL12026 Drivers: - Drivers exposing the RTC non volatile memory have been converted to use nvmem - Removed useless time and date validation - Removed an indirection pattern that was a cargo cult from ancient drivers - Removed VLA usage - Fixed a possible race condition in probe functions - AB8540 support is dropped from ab8500 - pcf85363 now has alarm support" * tag 'rtc-4.17' of git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux: (128 commits) rtc: snvs: Fix usage of snvs_rtc_enable rtc: mt7622: fix module autoloading for OF platform drivers rtc: isl12022: use true and false for boolean values rtc: ab8500: Drop AB8540 support rtc: remove a warning during scripts/kernel-doc step rtc: 88pm860x: remove artificial limitation rtc: 88pm80x: remove artificial limitation rtc: st-lpc: remove artificial limitation rtc: mrst: remove artificial limitation rtc: mv: remove artificial limitation rtc: hctosys: Ensure system time doesn't overflow time_t parisc: time: stop validating rtc_time in .read_time rtc: pcf85063: fix clearing bits in pcf85063_start_clock rtc: at91sam9: Set name of regmap_config rtc: s5m: Remove VLA usage rtc: s5m: Move enum from rtc.h to rtc-s5m.c rtc: remove VLA usage rtc: Add useful timestamp definitions rtc: Add one offset seconds to expand RTC range rtc: Factor out the RTC range validation into rtc_valid_range() ...
2018-03-09mn10300: Remove the architectureDavid Howells
Remove the MN10300 arch as the hardware is defunct. Suggested-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: David Howells <dhowells@redhat.com> cc: Masahiro Yamada <yamada.masahiro@socionext.com> cc: linux-am33-list@redhat.com Signed-off-by: Arnd Bergmann <arnd@arndb.de>