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path: root/drivers/rtc
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2018-04-25rtc: opal: Fix OPAL RTC driver OPAL_BUSY loopsNicholas Piggin
The OPAL RTC driver does not sleep in case it gets OPAL_BUSY or OPAL_BUSY_EVENT from firmware, which causes large scheduling latencies, up to 50 seconds have been observed here when RTC stops responding (BMC reboot can do it). Fix this by converting it to the standard form OPAL_BUSY loop that sleeps. Fixes: 628daa8d5abf ("powerpc/powernv: Add RTC and NVRAM support plus RTAS fallbacks") Cc: stable@vger.kernel.org # v3.2+ Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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() ...
2018-04-05Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial Pull trivial tree updates from Jiri Kosina. * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: kfifo: fix inaccurate comment tools/thermal: tmon: fix for segfault net: Spelling s/stucture/structure/ edd: don't spam log if no EDD information is present Documentation: Fix early-microcode.txt references after file rename tracing: Block comments should align the * on each line treewide: Fix typos in printk GenWQE: Fix a typo in two comments treewide: Align function definition open/close braces
2018-04-03rtc: snvs: Fix usage of snvs_rtc_enableBryan O'Donoghue
commit 179a502f8c46 ("rtc: snvs: add Freescale rtc-snvs driver") introduces the SNVS RTC driver with a function snvs_rtc_enable(). snvs_rtc_enable() can return an error on the enable path however this driver does not currently trap that failure on the probe() path and consequently if enabling the RTC fails we encounter a later error spinning forever in rtc_write_sync_lp(). [ 36.093481] [<c010d630>] (__irq_svc) from [<c0c2e9ec>] (_raw_spin_unlock_irqrestore+0x34/0x44) [ 36.102122] [<c0c2e9ec>] (_raw_spin_unlock_irqrestore) from [<c072e32c>] (regmap_read+0x4c/0x5c) [ 36.110938] [<c072e32c>] (regmap_read) from [<c085d0f4>] (rtc_write_sync_lp+0x6c/0x98) [ 36.118881] [<c085d0f4>] (rtc_write_sync_lp) from [<c085d160>] (snvs_rtc_alarm_irq_enable+0x40/0x4c) [ 36.128041] [<c085d160>] (snvs_rtc_alarm_irq_enable) from [<c08567b4>] (rtc_timer_do_work+0xd8/0x1a8) [ 36.137291] [<c08567b4>] (rtc_timer_do_work) from [<c01441b8>] (process_one_work+0x28c/0x76c) [ 36.145840] [<c01441b8>] (process_one_work) from [<c01446cc>] (worker_thread+0x34/0x58c) [ 36.153961] [<c01446cc>] (worker_thread) from [<c014aee4>] (kthread+0x138/0x150) [ 36.161388] [<c014aee4>] (kthread) from [<c0107e14>] (ret_from_fork+0x14/0x20) [ 36.168635] rcu_sched kthread starved for 2602 jiffies! g496 c495 f0x2 RCU_GP_WAIT_FQS(3) ->state=0x0 ->cpu=0 [ 36.178564] rcu_sched R running task 0 8 2 0x00000000 [ 36.185664] [<c0c288b0>] (__schedule) from [<c0c29134>] (schedule+0x3c/0xa0) [ 36.192739] [<c0c29134>] (schedule) from [<c0c2db80>] (schedule_timeout+0x78/0x4e0) [ 36.200422] [<c0c2db80>] (schedule_timeout) from [<c01a7ab0>] (rcu_gp_kthread+0x648/0x1864) [ 36.208800] [<c01a7ab0>] (rcu_gp_kthread) from [<c014aee4>] (kthread+0x138/0x150) [ 36.216309] [<c014aee4>] (kthread) from [<c0107e14>] (ret_from_fork+0x14/0x20) This patch fixes by parsing the result of rtc_write_sync_lp() and propagating both in the probe and elsewhere. If the RTC doesn't start we don't proceed loading the driver and don't get into this loop mess later on. Fixes: 179a502f8c46 ("rtc: snvs: add Freescale rtc-snvs driver") Signed-off-by: Bryan O'Donoghue <pure.logic@nexus-software.ie> Acked-by: Shawn Guo <shawn.guo@linaro.org> Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2018-04-03rtc: mt7622: fix module autoloading for OF platform driversSean Wang
It's required to create a modules.alias via MODULE_DEVICE_TABLE helper for the OF platform driver. Otherwise, module autoloading cannot work. Signed-off-by: Sean Wang <sean.wang@mediatek.com> Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2018-04-03rtc: isl12022: use true and false for boolean valuesGustavo A. R. Silva
Assign true or false to boolean variables instead of an integer value. This issue was detected with the help of Coccinelle. Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2018-03-27rtc: ab8500: Drop AB8540 supportLinus Walleij
The AB8540 was an evolved version of the AB8500, but it was never mass produced or put into products, only reference designs exist. The upstream support was never completed and it is unlikely that this will happen so drop the support for now to simplify maintenance of the AB8500. Cc: Loic Pallardy <loic.pallardy@st.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2018-03-27rtc: remove a warning during scripts/kernel-doc stepMathieu Malaterre
During compilation using W=1 one would get: drivers/rtc/systohc.c:11: info: Scanning doc for rtc_set_ntp_time drivers/rtc/systohc.c:23: warning: bad line: ( Signed-off-by: Mathieu Malaterre <malat@debian.org> Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2018-03-27rtc: 88pm860x: remove artificial limitationAlexandre Belloni
The 88pm860x supports time up to 2106 (it is a 32 bit counter). Also, the year will never be before 1970 as the RTC core forbids that. Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2018-03-27rtc: 88pm80x: remove artificial limitationAlexandre Belloni
The 88pm80x supports time up to 2106 (it is a 32 bit counter). Also, the year will never be before 1970 as the RTC core forbids that. Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2018-03-27rtc: st-lpc: remove artificial limitationAlexandre Belloni
The LPC RTC supports dates way beyond 2038, don't limit it artificially as the kernel handles dates after 2038 properly. Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2018-03-27rtc: mrst: remove artificial limitationAlexandre Belloni
The hardware supports years up to 100 so don't limit the year to 2038 artificially. Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2018-03-27rtc: mv: remove artificial limitationAlexandre Belloni
Dates after 2038 actually fit on 32 bits. The counter will overflow in 2106. Also, it is bad practice to reset the RTC to a default value. Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2018-03-27rtc: hctosys: Ensure system time doesn't overflow time_tAlexandre Belloni
On 32bit platforms, time_t is still a signed 32bit long. If it is overflowed, userspace and the kernel cant agree on the current system time. This causes multiple issues, in particular with systemd: https://github.com/systemd/systemd/issues/1143 A good workaround is to simply avoid using hctosys which is something I greatly encourage as the time is better set by userspace. However, many distribution enable it and use systemd which is rendering the system unusable in case the RTC holds a date after 2038 (and more so after 2106). Many drivers have workaround for this case and they should be eliminated so there is only one place left to fix when userspace is able to cope with dates after the 31bit overflow. Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2018-03-26rtc: remove bfin driverArnd Bergmann
The blackfin architecture is getting removed, so this one is now obsolete. Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Acked-by: Aaron Wu <aaron.wu@analog.com> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2018-03-26rtc: remove tile driverArnd Bergmann
The tile architecture is getting removed, so this driver is no longer needed. Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2018-03-26treewide: simplify Kconfig dependencies for removed archsArnd Bergmann
A lot of Kconfig symbols have architecture specific dependencies. In those cases that depend on architectures we have already removed, they can be omitted. Acked-by: Kalle Valo <kvalo@codeaurora.org> Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2018-03-26treewide: Align function definition open/close bracesJoe Perches
Some functions definitions have either the initial open brace and/or the closing brace outside of column 1. Move those braces to column 1. This allows various function analyzers like gnu complexity to work properly for these modified functions. Signed-off-by: Joe Perches <joe@perches.com> Acked-by: Andy Shevchenko <andy.shevchenko@gmail.com> Acked-by: Paul Moore <paul@paul-moore.com> Acked-by: Alex Deucher <alexander.deucher@amd.com> Acked-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com> Acked-by: Martin K. Petersen <martin.petersen@oracle.com> Acked-by: Takashi Iwai <tiwai@suse.de> Acked-by: Mauro Carvalho Chehab <mchehab@s-opensource.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Nicolin Chen <nicoleotsuka@gmail.com> Acked-by: Martin K. Petersen <martin.petersen@oracle.com> Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2018-03-17rtc: pcf85063: fix clearing bits in pcf85063_start_clockMichael McCormick
Bit clear operation was missing ~ Signed-off-by: Michael McCormick <michael.mccormick@enatel.net> Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2018-03-17rtc: at91sam9: Set name of regmap_configJeffy Chen
We are now allowing to register debugfs without a valid device, and not having a valid name will end up using "dummy*" to create debugfs dir. Signed-off-by: Jeffy Chen <jeffy.chen@rock-chips.com> Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2018-03-17rtc: s5m: Remove VLA usageGustavo A. R. Silva
In preparation to enabling -Wvla, remove VLAs and replace them with fixed-length arrays instead. >From a security viewpoint, the use of Variable Length Arrays can be a vector for stack overflow attacks. Also, in general, as the code evolves it is easy to lose track of how big a VLA can get. Thus, we can end up having segfaults that are hard to debug. Also, fixed as part of the directive to remove all VLAs from the kernel: https://lkml.org/lkml/2018/3/7/621 Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> Reviewed-by: Krzysztof Kozlowski <krzk@kernel.org> Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2018-03-17rtc: s5m: Move enum from rtc.h to rtc-s5m.cGustavo A. R. Silva
Move this enum to rtc-s5m.c once it is meaningless to others drivers [1]. [1] https://marc.info/?l=linux-rtc&m=152060068925948&w=2 Suggested-by: Krzysztof Kozlowski <krzk@kernel.org> Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> Reviewed-by: Krzysztof Kozlowski <krzk@kernel.org> Acked-by: Lee Jones <lee.jones@linaro.org> Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2018-03-17rtc: remove VLA usageGustavo A. R. Silva
In preparation to enabling -Wvla, remove VLA and replace it with a fixed-length array instead. >From a security viewpoint, the use of Variable Length Arrays can be a vector for stack overflow attacks. Also, in general, as the code evolves it is easy to lose track of how big a VLA can get. Thus, we can end up having segfaults that are hard to debug. Also, fixed as part of the directive to remove all VLAs from the kernel: https://lkml.org/lkml/2018/3/7/621 Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com> Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2018-03-17rtc: Add one offset seconds to expand RTC rangeBaolin Wang
From our investigation for all RTC drivers, 1 driver will be expired before year 2017, 7 drivers will be expired before year 2038, 23 drivers will be expired before year 2069, 72 drivers will be expired before 2100 and 104 drivers will be expired before 2106. Especially for these early expired drivers, we need to expand the RTC range to make the RTC can still work after the expired year. So we can expand the RTC range by adding one offset to the time when reading from hardware, and subtracting it when writing back. For example, if you have an RTC that can do 100 years, and currently is configured to be based in Jan 1 1970, so it can represents times from 1970 to 2069. Then if you change the start year from 1970 to 2000, which means it can represents times from 2000 to 2099. By adding or subtracting the offset produced by moving the wrap point, all times between 1970 and 1999 from RTC hardware could get interpreted as times from 2070 to 2099, but the interpretation of dates between 2000 and 2069 would not change. Signed-off-by: Baolin Wang <baolin.wang@linaro.org> Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2018-03-17rtc: Factor out the RTC range validation into rtc_valid_range()Baolin Wang
The RTC range validation code can be factored into rtc_valid_range() function to avoid duplicate code. Signed-off-by: Baolin Wang <baolin.wang@linaro.org> Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2018-03-17rtc: Add RTC rangeAlexandre Belloni
Add a way for drivers to inform the core of the supported date/time range. The core can then check whether the date/time or alarm is in the range before calling ->set_time, ->set_mmss or ->set_alarm. It returns -ERANGE when the time is out of range. Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2018-03-17rtc: isl1208: switch to rtc_register_deviceDenis Osterland
Fix possible race condition. It is not allowed to return with an error code after RTC is registered. Suggested-by: Alexandre Belloni <alexandre.belloni@free-electrons.com> Signed-off-by: Denis Osterland <Denis.Osterland@diehl.com> Reviewed-by: Michael Grzeschik <m.grzeschik@pengutronix.de> Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2018-03-17rtc: isl1208: enable interrupt after context preparationMichael Grzeschik
The interrupt handler got enabled very early. If the interrupt cause is triggering immediately before the context is fully prepared. This can lead to undefined behaviour. Therefor we move the interrupt enable code to the end of the probe function. Signed-off-by: Michael Grzeschik <m.grzeschik@pengutronix.de> Signed-off-by: Denis Osterland <Denis.Osterland@diehl.com> Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2018-03-17rtc: cros-ec: return -ETIME when refused to set alarms in the pastJeffy Chen
Since accessing a Chrome OS EC based rtc is a slow operation, there is a race window where if the alarm is set for the next second and the second ticks over right before calculating the alarm offset. In this case the current driver is setting a 0-second alarm, which would be considered as disabling alarms by the EC(EC_RTC_ALARM_CLEAR). This breaks, e.g., hwclock which relies on RTC_UIE_ON -> rtc_update_irq_enable(), which sets a 1-second alarm and expects it to fire an interrupt. So return -ETIME when the alarm is in the past, follow __rtc_set_alarm(). Signed-off-by: Jeffy Chen <jeffy.chen@rock-chips.com> Reviewed-by: Brian Norris <briannorris@chromium.org> Tested-by: Brian Norris <briannorris@chromium.org> Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2018-03-17rtc: pm8xxx: Fix issue in RTC write pathMohit Aggarwal
In order to set time in rtc, need to disable rtc hw before writing into rtc registers. Also fixes disabling of alarm while setting rtc time. Signed-off-by: Mohit Aggarwal <maggarwa@codeaurora.org> Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2018-03-17rtc: at91sam: add 'depends on HAS_IOMEM' to fix unmet dependencyMasahiro Yamada
This config select's MFD_SYSCON, but does not depend on HAS_IOMEM. Compile testing on architecture without HAS_IOMEM causes "unmet direct dependencies" in Kconfig phase. Detected by "make ARCH=score allyesconfig". Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2018-03-17rtc: isl12026: fixup nvmem registrationAlexandre Belloni
The probe function must not fail after rtc_register_device. Also, rename the nvmem device so it is easily identifiable in /sys/bus/nvmem. Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2018-03-17rtc: isl12026: new driver.David Daney
The ISL12026 is a combination RTC and EEPROM device with I2C interface. The standard RTC driver interface is provided. The EEPROM is accessed via the NVMEM interface. Reviewed-by: Rob Herring <robh@kernel.org> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Signed-off-by: David Daney <david.daney@cavium.com> Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2018-03-17rtc: brcmstb-waketimer: Set wktmr prescalerJustin Chen
The HW default is one tick per second, however instead of assuming this, lets make sure the waketimer is actually one tick per second before arming the alarm. Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: Justin Chen <justinpopo6@gmail.com> Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2018-03-17rtc: fix rtc_time64_to_tm for 3477Alexandre Belloni
The current correction for leap years will fail in 3477. 3476-12-31 being 3477-01-00 because this is 366 leap years after 1970 and 3477 isn't a leap year. Fix that by looping over until days is positive or zero. Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2018-03-17rtc: ac100: Fix ac100 determine rate bugPhilipp Rossak
This patch fixes a bug, that prevents the Allwinner A83T and the A80 from a successful boot. The bug is there since v4.16-rc1 and appeared after the clk branch was merged. You can find the shortend trace below: Unable to handle kernel NULL pointer dereference at virtual address 00000000 pgd = (ptrval) [00000000] *pgd=00000000 Internal error: Oops: 5 [#1] SMP ARM Modules linked in: CPU: 0 PID: 49 Comm: kworker/0:1 Not tainted 4.15.0-10190-gb89e32ccd1be #2 Hardware name: Allwinner sun8i Family Workqueue: events deferred_probe_work_func PC is at clk_hw_get_rate+0x0/0x34 LR is at ac100_clkout_determine_rate+0x48/0x19c [ ... ] (clk_hw_get_rate) from (ac100_clkout_determine_rate+0x48/0x19c) (ac100_clkout_determine_rate) from (clk_core_set_rate_nolock+0x3c/0x1a0) (clk_core_set_rate_nolock) from (clk_set_rate+0x30/0x88) (clk_set_rate) from (of_clk_set_defaults+0x200/0x364) (of_clk_set_defaults) from (platform_drv_probe+0x18/0xb0) To fix that bug, we first check if the return of the clk_hw_get_parent_by_index is non zero. If it is zero we skip that clock parent. The BUG report could be found here: https://lkml.org/lkml/2018/2/10/198 Fixes: 04940631b8d2 ("rtc: ac100: Add clk output support") Signed-off-by: Philipp Rossak <embed3d@gmail.com> Acked-by: Maxime Ripard <maxime.ripard@bootlin.com> Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2018-03-17rtc: pcf85363: set time accuratelyAlexandre Belloni
As per 8.2.6 Setting and reading the time in RTC mode, first stop the clok, then reset it before setting the date and time registers. Finally, start the clock. This uses register address wrap around from 0x2f to 0x00 for efficiency. This allows to set the clock with a millisecond accuracy (drift is not corrected in this example): RTC System 1325388767 1325388767.000029180 1325388768 1325388768.000018362 1325388769 1325388769.000006544 1325388770 1325388769.999992725 1325388771 1325388770.999974544 Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2018-03-17rtc: pcf85363: add alarm supportAlexandre Belloni
Handle alarms, currently only on INTA Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2018-03-17rtc: pcf85363: add .max_register in regmap_configAlexandre Belloni
This helps debugging as it allows reading registers from debugfs. Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2018-03-17rtc: m41t80: remove useless indirectionAlexandre Belloni
m41t80_get_datetime and m41t80_set_datetime are only used after casting dev to an i2c_client. Remove that useless indirection. Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2018-03-17rtc: m41t80: fix race conditionsAlexandre Belloni
The IRQ is requested before the struct rtc is allocated and registered, but this struct is used in the IRQ handler, leading to: Unable to handle kernel NULL pointer dereference at virtual address 0000017c pgd = a38a2f9b [0000017c] *pgd=00000000 Internal error: Oops: 5 [#1] ARM Modules linked in: CPU: 0 PID: 613 Comm: irq/48-m41t80 Not tainted 4.16.0-rc1+ #42 Hardware name: Atmel SAMA5 PC is at mutex_lock+0x14/0x38 LR is at m41t80_handle_irq+0x1c/0x9c pc : [<c06e864c>] lr : [<c04b70f0>] psr: 20000013 sp : dec73f30 ip : 00000000 fp : dec56d98 r10: df437cf0 r9 : c0a03008 r8 : c0145ffc r7 : df5c4300 r6 : dec568d0 r5 : df593000 r4 : 0000017c r3 : df592800 r2 : 60000013 r1 : df593000 r0 : 0000017c Flags: nzCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment none Control: 10c53c7d Table: 20004059 DAC: 00000051 Process irq/48-m41t80 (pid: 613, stack limit = 0xb52d091e) Stack: (0xdec73f30 to 0xdec74000) 3f20: dec56840 df5c4300 00000001 df5c4300 3f40: c0145ffc c0146018 dec56840 ffffe000 00000001 c0146290 dec567c0 00000000 3f60: c0146084 ed7c9a62 c014615c dec56d80 dec567c0 00000000 dec72000 dec56840 3f80: c014615c c012ffc0 dec72000 dec567c0 c012fe80 00000000 00000000 00000000 3fa0: 00000000 00000000 00000000 c01010e8 00000000 00000000 00000000 00000000 3fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 3fe0: 00000000 00000000 00000000 00000000 00000013 00000000 29282726 2d2c2b2a [<c06e864c>] (mutex_lock) from [<c04b70f0>] (m41t80_handle_irq+0x1c/0x9c) [<c04b70f0>] (m41t80_handle_irq) from [<c0146018>] (irq_thread_fn+0x1c/0x54) [<c0146018>] (irq_thread_fn) from [<c0146290>] (irq_thread+0x134/0x1c0) [<c0146290>] (irq_thread) from [<c012ffc0>] (kthread+0x140/0x148) [<c012ffc0>] (kthread) from [<c01010e8>] (ret_from_fork+0x14/0x2c) Exception stack(0xdec73fb0 to 0xdec73ff8) 3fa0: 00000000 00000000 00000000 00000000 3fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 3fe0: 00000000 00000000 00000000 00000000 00000013 00000000 Code: e3c33d7f e3c3303f f5d0f000 e593300c (e1901f9f) ---[ end trace 22b027302eb7c604 ]--- genirq: exiting task "irq/48-m41t80" (613) is an active IRQ thread (irq 48) Also, there is another possible race condition. The probe function is not allowed to fail after the RTC is registered because the following may happen: CPU0: CPU1: sys_load_module() do_init_module() do_one_initcall() cmos_do_probe() rtc_device_register() __register_chrdev() cdev->owner = struct module* open("/dev/rtc0") rtc_device_unregister() module_put() free_module() module_free(mod->module_core) /* struct module *module is now freed */ chrdev_open() spin_lock(cdev_lock) cdev_get() try_module_get() module_is_live() /* dereferences already freed struct module* */ Switch to devm_rtc_allocate_device/rtc_register_device to allocate the rtc before requesting the IRQ and register it as late as possible. Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2018-03-17rtc: m41t80: move m41t80_rtc_mutex to the block where it is usedSebastian Andrzej Siewior
Without CONFIG_RTC_DRV_M41T80_WDT the compiler complains: |drivers/rtc/rtc-m41t80.c:76 ‘m41t80_rtc_mutex’ defined but not used [-Wunused-variable] Move the variable to the block where it is used. Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2018-03-17rtc: pcf85063: remove useless indirectionAlexandre Belloni
pcf85063_get_datetime and pcf85063_set_datetime are only used after casting dev to an i2c_client. Remove that useless indirection. Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2018-03-17rtc: pcf85063: stop validating rtc_time in .read_timeAlexandre Belloni
The RTC core is always calling rtc_valid_tm after the read_time callback. It is not necessary to call it before returning from the callback. Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2018-03-17rtc: max6900: remove useless indirectionAlexandre Belloni
max6900_i2c_read_time and max6900_i2c_set_time are only used after casting dev to an i2c_client. Remove that useless indirection. Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2018-03-17rtc: max6900: stop validating rtc_time in .read_timeAlexandre Belloni
The RTC core is always calling rtc_valid_tm after the read_time callback. It is not necessary to call it before returning from the callback. Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2018-03-17rtc: rs5c372: remove useless indirectionAlexandre Belloni
rs5c372_get_datetime and rs5c372_set_datetime are only used after casting dev to an i2c_client. Remove that useless indirection. Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2018-03-17rtc: rs5c372: stop validating rtc_time in .read_timeAlexandre Belloni
The RTC core is always calling rtc_valid_tm after the read_time callback. It is not necessary to call it before returning from the callback. Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2018-03-17rtc: rs5c372: remove useless messageAlexandre Belloni
It is not necessary to print a message when the time is invalid as userspace will already get an error (and an optional dev_dbg message). Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2018-03-17rtc: s35390a: remove useless indirectionAlexandre Belloni
s35390a_set_datetime, s35390a_get_datetime, s35390a_set_alarm and s35390a_read_alarm are only used after casting dev to an i2c_client. Remove that useless indirection. Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>