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Since we have now a common helper to read port properties
use it instead of sparse home grown solution.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20240304123035.758700-12-andriy.shevchenko@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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We need the serial fixes in here as well to build off of.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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This fixes commit 439c7183e5b9 ("serial: 8250: 8250_omap: Disable RX
interrupt after DMA enable") which unfortunately set the
UART_HAS_RHR_IT_DIS bit in the UART_OMAP_IER2 register and never
cleared it.
Cc: stable@vger.kernel.org
Fixes: 439c7183e5b9 ("serial: 8250: 8250_omap: Disable RX interrupt after DMA enable")
Signed-off-by: Ronald Wahl <ronald.wahl@raritan.com>
Reviewed-by: Vignesh Raghavendra <vigneshr@ti.com>
Link: https://lore.kernel.org/r/20231031110909.11695-1-rwahl@gmx.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Starting RX DMA on THRI interrupt is too early because TX may not have
finished yet.
This change is inspired by commit 90b8596ac460 ("serial: 8250: Prevent
starting up DMA Rx on THRI interrupt") and fixes DMA issues I had with
an AM62 SoC that is using the 8250 OMAP variant.
Cc: stable@vger.kernel.org
Fixes: c26389f998a8 ("serial: 8250: 8250_omap: Add DMA support for UARTs on K3 SoCs")
Signed-off-by: Ronald Wahl <ronald.wahl@raritan.com>
Reviewed-by: Vignesh Raghavendra <vigneshr@ti.com>
Link: https://lore.kernel.org/r/20231101171431.16495-1-rwahl@gmx.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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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 ignored (apart
from emitting a warning) 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. Eventually after all drivers
are converted, .remove_new() will be renamed to .remove().
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>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Reviewed-by: Andi Shyti <andi.shyti@linux.intel.com>
Reviewed-by: Florian Fainelli <florian.fainelli@broadcom.com> # 8250_bcm*
Link: https://lore.kernel.org/r/20231110152927.70601-4-u.kleine-koenig@pengutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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pm_runtime_resume_and_get() failed
Returning an error code from .remove() makes the driver core emit the
little helpful error message:
remove callback returned a non-zero value. This will be ignored.
and then remove the device anyhow. So all resources that were not freed
are leaked in this case. Skipping serial8250_unregister_port() has the
potential to keep enough of the UART around to trigger a use-after-free.
So replace the error return (and with it the little helpful error
message) by a more useful error message and continue to cleanup.
Fixes: e3f0c638f428 ("serial: 8250: omap: Fix unpaired pm_runtime_put_sync() in omap8250_remove()")
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Tony Lindgren <tony@atomide.com>
Link: https://lore.kernel.org/r/20231110152927.70601-2-u.kleine-koenig@pengutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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If the console suspend is disabled, the genpd of the console shall not
be powered-off during suspend.
Set the flag GENPD_FLAG_ALWAYS_ON to the corresponding genpd during
suspend, and restore the original value during the resume.
Signed-off-by: Thomas Richard <thomas.richard@bootlin.com>
Link: https://lore.kernel.org/r/20231017130540.1149721-1-thomas.richard@bootlin.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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We need the tty/serial fixes in here as well for testing, and this
resolves merge conflicts in:
drivers/tty/serial/serial_core.c
as reported in linux-next
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Let's drop the use of pm_runtime_irq_safe() for 8250_omap. The use of
pm_runtime_irq_safe() is not nice as it takes a permanent usage count on
the parent device.
We can finally drop pm_runtime_irq_safe() safely as the kernel now knows
when the uart port tx is active. This changed with commit 84a9582fd203
("serial: core: Start managing serial controllers to enable runtime PM").
For serial port rx, we already use Linux generic wakeirqs for 8250_omap.
To drop pm_runtime_irq_safe(), we need to add handling for shallow idle
state where the port hardware may already be awake and an IO interrupt
happens. We also need to replace the serial8250_rpm sync calls in the
interrupt handlers with async runtime PM calls.
Note that omap8250_irq() calls omap_8250_dma_handle_irq(), so we don't
need separate runtime PM calls in omap_8250_dma_handle_irq().
While at it, let's also add the missing line break to the end of
omap8250_runtime_resume() to group the calls.
Signed-off-by: Tony Lindgren <tony@atomide.com>
Link: https://lore.kernel.org/r/20231004062650.64487-1-tony@atomide.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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We now get errors on system suspend if no_console_suspend is set as
reported by Thomas. The errors started with commit 20a41a62618d ("serial:
8250_omap: Use force_suspend and resume for system suspend").
Let's fix the issue by checking for console_suspend_enabled in the system
suspend and resume path.
Note that with this fix the checks for console_suspend_enabled in
omap8250_runtime_suspend() become useless. We now keep runtime PM usage
count for an attached kernel console starting with commit bedb404e91bb
("serial: 8250_port: Don't use power management for kernel console").
Fixes: 20a41a62618d ("serial: 8250_omap: Use force_suspend and resume for system suspend")
Cc: stable <stable@kernel.org>
Cc: Udit Kumar <u-kumar1@ti.com>
Reported-by: Thomas Richard <thomas.richard@bootlin.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Tested-by: Thomas Richard <thomas.richard@bootlin.com>
Reviewed-by: Dhruva Gole <d-gole@ti.com>
Link: https://lore.kernel.org/r/20230926061319.15140-1-tony@atomide.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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When a serial port is used for kernel console output, then all
modifications to the UART registers which are done from other contexts,
e.g. getty, termios, are interference points for the kernel console.
So far this has been ignored and the printk output is based on the
principle of hope. The rework of the console infrastructure which aims to
support threaded and atomic consoles, requires to mark sections which
modify the UART registers as unsafe. This allows the atomic write function
to make informed decisions and eventually to restore operational state. It
also allows to prevent the regular UART code from modifying UART registers
while printk output is in progress.
All modifications of UART registers are guarded by the UART port lock,
which provides an obvious synchronization point with the console
infrastructure.
To avoid adding this functionality to all UART drivers, wrap the
spin_[un]lock*() invocations for uart_port::lock into helper functions
which just contain the spin_[un]lock*() invocations for now. In a
subsequent step these helpers will gain the console synchronization
mechanisms.
Converted with coccinelle. No functional change.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Link: https://lore.kernel.org/r/20230914183831.587273-13-john.ogness@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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The DT of_device.h and of_platform.h date back to the separate
of_platform_bus_type before it as merged into the regular platform bus.
As part of that merge prepping Arm DT support 13 years ago, they
"temporarily" include each other. They also include platform_device.h
and of.h. As a result, there's a pretty much random mix of those include
files used throughout the tree. In order to detangle these headers and
replace the implicit includes with struct declarations, users need to
explicitly include the correct includes.
Signed-off-by: Rob Herring <robh@kernel.org>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> # for imx
Link: https://lore.kernel.org/r/20230724205440.767071-1-robh@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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We should not rely on autosuspend timeout for system suspend. Instead,
let's use force_suspend and force_resume functions. Otherwise the serial
port controller device may not be idled on suspend.
As we are doing a register write on suspend to configure the serial port,
we still need to runtime PM resume the port on suspend.
While at it, let's switch to pm_runtime_resume_and_get() and check for
errors returned. And let's add the missing line break before return to the
suspend function while at it.
Fixes: 09d8b2bdbc5c ("serial: 8250: omap: Provide ability to enable/disable UART as wakeup source")
Signed-off-by: Tony Lindgren <tony@atomide.com>
Tested-by: Dhruva Gole <d-gole@ti.com>
Message-ID: <20230614045922.4798-1-tony@atomide.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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The new uart_write() function is only called from suspend/resume code, causing
a build warning when those are left out:
drivers/tty/serial/8250/8250_omap.c:169:13: error: 'uart_write' defined but not used [-Werror=unused-function]
Remove the #ifdefs and use the modern pm_ops/pm_sleep_ops and their wrappers
to let the compiler see where it's used but still drop the dead code.
Fixes: 398cecc24846 ("serial: 8250: omap: Fix imprecise external abort for omap_8250_pm()")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Tony Lindgren <tony@atomide.com>
Link: https://lore.kernel.org/r/20230517202012.634386-1-arnd@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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If CONFIG_PM is not set (e.g. m68k/allmodconfig):
drivers/tty/serial/8250/8250_omap.c:169:13: error: ‘uart_write’ defined but not used [-Werror=unused-function]
169 | static void uart_write(struct omap8250_priv *priv, u32 reg, u32 val)
| ^~~~~~~~~~
Fix tis by moving uart_write() inside the existing section protected
by #ifdef CONFIG_PM.
Reported-by: noreply@ellerman.id.au
Link: http://kisskb.ellerman.id.au/kisskb/buildresult/14925095/
Fixes: 398cecc24846e867 ("serial: 8250: omap: Fix imprecise external abort for omap_8250_pm()")
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Reviewed-by: Tony Lindgren <tony@atomide.com>
Link: https://lore.kernel.org/r/20230515065706.1723477-1-geert@linux-m68k.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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The UART_IER register is modified twice by each console write
(serial8250_console_write()) under the port lock. Any driver code that
accesses UART_IER must do so with the port locked in order to ensure
consistent values, even when for read accesses.
Add locking, lockdep notation, and/or comments everywhere UART_IER is
accessed. The added locking is not fixing a real problem because it
occurs where the console is not active. However, adding the locking
to these non-critical paths greatly simplifies UART_IER access
tracking by establishing a general policy that all UART_IER access
is performed with the port locked.
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Link: https://lore.kernel.org/r/20230525093159.223817-9-john.ogness@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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omap8250_irq() accesses UART_IER. This register is modified twice
by each console write (serial8250_console_write()) under the port
lock. omap8250_irq() must also take the port lock to guanentee
synchronized access to UART_IER.
Since the port lock is already being taken for the stop_rx() callback
and since it is safe to call cancel_delayed_work() while holding the
port lock, simply extend the port lock region to include UART_IER
access.
Fixes: 1fe0e1fa3209 ("serial: 8250_omap: Handle optional overrun-throttle-ms property")
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Tony Lindgren <tony@atomide.com>
Link: https://lore.kernel.org/r/20230525093159.223817-8-john.ogness@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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omap8250_restore_regs() accesses UART_IER. This register is
modified twice by each console write (serial8250_console_write())
under the port lock. However, not all calls to omap8250_restore_regs()
are under the port lock.
Add the missing port locking around omap8250_restore_regs() calls. Add
lockdep notation to the omap8250_restore_regs().
Note that this is not fixing a real problem because the serial devices
are resumed before console printing is enabled.
However, adding this locking allows for clean locking semantics
for omap8250_restore_regs() so that lockdep can be used to identify
possible problems in the future. It also simplifies synchronization
of UART_IER in general by not needing to rely on such implementation
details.
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Link: https://lore.kernel.org/r/20230525093159.223817-7-john.ogness@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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The rx_dma() callback (omap_8250_rx_dma) accesses UART_IER. This
register is modified twice by each console write
(serial8250_console_write()) under the port lock. However, not
all calls to the rx_dma() callback are under the port lock.
Add the missing port locking around rx_dma() callback calls. Add
lockdep notation to the omap_8250_rx_dma().
Note that this is not fixing a real problem because:
1. Currently DMA is forced off for 8250_omap consoles.
2. The serial devices are resumed before console printing is enabled.
However, adding this locking allows for clean locking semantics
for the rx_dma() callback so that lockdep can be used to identify
possible problems in the future. It also simplifies synchronization
of UART_IER in general by not needing to rely on implementation
details such as 1 and 2.
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Link: https://lore.kernel.org/r/20230525093159.223817-6-john.ogness@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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The uarts_ops stop_rx() callback expects that the port->lock is
taken and interrupts are disabled.
Fixes: 1fe0e1fa3209 ("serial: 8250_omap: Handle optional overrun-throttle-ms property")
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Tony Lindgren <tony@atomide.com>
Link: https://lore.kernel.org/r/20230525093159.223817-4-john.ogness@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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uart_ops startup() callback is called without interrupts
disabled and without port->lock locked, relatively late during the
boot process (from the call path of console_on_rootfs()). If the
device is a console, it was already previously registered and could
be actively printing messages.
The console printing function serial8250_console_write() modifies
the interrupt register (UART_IER) under the port->lock with the
pattern: read, clear, restore.
Since some startup() callbacks are modifying UART_IER without the
port->lock locked, it is possible that the value intended to be
written by the startup() callback will get overwritten and be
lost.
CPU0 CPU1
serial8250_console_write omap_8250_startup
-------------------------- -----------------
spin_lock(port->lock)
oldval = read(UART_IER)
uart_console_write()
write(newval, UART_IER)
write(oldval, UART_IER)
spin_unlock(port->lock)
Add port->lock synchronization to the 8250 startup() callbacks
where they need to access UART_IER. This avoids racing with
serial8250_console_write().
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Link: https://lore.kernel.org/r/20230525093159.223817-2-john.ogness@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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When unbinding the console uart, we want to power down the uart hardware
on remove. For the console uart, the normal shutdown path will never get
called as the cons_filp stays open. Let's rearrange the dma related
functions a bit so we can call driver shutdown also on console uart rebind.
Currently we set up->dma on probe, but that causes issues calling
omap_8250_shutdown() on remove. The dma startup will not get called on
the next rebind as we still have up->dma set from probe.
Note that serial8250_release_dma() already checks for dma so we can
remove the check for it in 8205_omap driver.
With these changes we also avoid hogging dma virtual channels for the
unused uarts that may be limited on some devices.
Signed-off-by: Tony Lindgren <tony@atomide.com>
Link: https://lore.kernel.org/r/20230508082014.23083-5-tony@atomide.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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We have the struct uart_8250_port instance recycled on device rebind while
the struct omap8250_priv instance is not. For the console uart,
__tty_hangup() does not call tty->ops->hangup() as cons_filp stays open,
and uart shutdown won't get called. This means we have a stale
priv->wakeirq handler around after unbind, and port->irq is not freed on
unbind.
There's no need to claim the interrupts on startup. We can fix this and
simplify the driver a bit by claiming the interrupts in probe, and clearing
them on remove. For the device interrupt, we can use devm_request_irq().
To do this, we change omap8250_irq() to use struct omap8250_priv data
directly so we don't have to wait for the assigned port from
serial8250_register_8250_port().
We must also drop IRQF_SHARED to set IRQ_NOAUTOEN to avoid spurious
interrupts until the port has been registered. There's no need for
IRQF_SHARED for 8250_omap, the serial port interrupt lines are dedicated
lines.
Signed-off-by: Tony Lindgren <tony@atomide.com>
Link: https://lore.kernel.org/r/20230508082014.23083-4-tony@atomide.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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We must idle the uart only after serial8250_unregister_port(). Otherwise
unbinding the uart via sysfs while doing cat on the port produces an
imprecise external abort:
mem_serial_in from omap_8250_pm+0x44/0xf4
omap_8250_pm from uart_hangup+0xe0/0x194
uart_hangup from __tty_hangup.part.0+0x37c/0x3a8
__tty_hangup.part.0 from uart_remove_one_port+0x9c/0x22c
uart_remove_one_port from serial8250_unregister_port+0x60/0xe8
serial8250_unregister_port from omap8250_remove+0x6c/0xd0
omap8250_remove from platform_remove+0x28/0x54
Turns out the driver needs to have runtime PM functional before the
driver probe calls serial8250_register_8250_port(). And it needs
runtime PM after driver remove calls serial8250_unregister_port().
On probe, we need to read registers before registering the port in
omap_serial_fill_features_erratas(). We do that with custom uart_read()
already.
On remove, after serial8250_unregister_port(), we need to write to the
uart registers to idle the device. Let's add a custom uart_write() for
that.
Currently the uart register access depends on port->membase to be
initialized, which won't work after serial8250_unregister_port().
Let's use priv->membase instead, and use it for runtime PM related
functions to remove the dependency to port->membase for early and
late register access.
Note that during use, we need to check for a valid port in the runtime PM
related functions. This is needed for the optional wakeup configuration.
We now need to set the drvdata a bit earlier so it's available for the
runtime PM functions.
With the port checks in runtime PM functions, the old checks for priv in
omap8250_runtime_suspend() and omap8250_runtime_resume() functions are no
longer needed and are removed.
Signed-off-by: Tony Lindgren <tony@atomide.com>
Link: https://lore.kernel.org/r/20230508082014.23083-3-tony@atomide.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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If serial8250_register_8250_port() fails, the SoC can hang as the
deferred PMQoS work will still run as is not flushed and removed.
Fixes: 61929cf0169d ("tty: serial: Add 8250-core based omap driver")
Signed-off-by: Tony Lindgren <tony@atomide.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20230508082014.23083-2-tony@atomide.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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We need the tty/serial fixes in here as well.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Commit 801954d1210a ("serial: 8250: 8250_omap: Support native RS485")
calculates RS485 delays from the baudrate. The baudrate is generated
with either a 16x or 13x divisor. The divisor is set in the Mode
Definition Register 1 (MDR1).
The commit erroneously assumes that the register stores the divisor as
a bitmask and uses a logical AND to differentiate between 16x and 13x
divisors. However the divisor is really stored as a 3-bit mode
(see lines 363ff in include/uapi/linux/serial_reg.h).
The logical AND operation is performed with UART_OMAP_MDR1_16X_MODE,
which is defined as 0x0 and hence yields false. So the commit always
assumes a 13x divisor. Fix by using an equal comparison. This works
because we never set any of the other 5 bits in the register. (They
pertain to IrDA mode, which is not supported by the driver).
Fixes: 801954d1210a ("serial: 8250: 8250_omap: Support native RS485")
Link: https://lore.kernel.org/linux-serial/202211070440.8hWunFUN-lkp@intel.com/
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/7d5b04da13d89b8708b9543a0b125f2b6062a77b.1667977259.git.lukas@wunner.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Rebinding 8250_omap in a loop will at some point produce a warning for
kernel/power/qos.c:296 cpu_latency_qos_update_request() with error
"cpu_latency_qos_update_request called for unknown object". Let's flush
the possibly pending PM QOS work scheduled from omap8250_runtime_suspend()
before we disable runtime PM.
Fixes: 61929cf0169d ("tty: serial: Add 8250-core based omap driver")
Signed-off-by: Tony Lindgren <tony@atomide.com>
Link: https://lore.kernel.org/r/20221028110044.54719-1-tony@atomide.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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On remove, we get an error for "Runtime PM usage count underflow!". I guess
this driver is mostly built-in, and this issue has gone unnoticed for a
while. Somehow I did not catch this issue with my earlier fix done with
commit 4e0f5cc65098 ("serial: 8250_omap: Fix probe and remove for PM
runtime").
Fixes: 4e0f5cc65098 ("serial: 8250_omap: Fix probe and remove for PM runtime")
Signed-off-by: Tony Lindgren <tony@atomide.com>
Depends-on: dd8088d5a896 ("PM: runtime: Add pm_runtime_resume_and_get to deal with usage counter")
Link: https://lore.kernel.org/r/20221028105813.54290-1-tony@atomide.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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We were occasionally seeing the "Errata i202: timedout" on an AM335x
board when repeatedly opening and closing a UART connected to an active
sender. As new input may arrive at any time, it is possible to miss the
"RX FIFO empty" condition, forcing the loop to wait until it times out.
Nothing in the i202 Advisory states that such a wait is even necessary;
other FIFO clear functions like serial8250_clear_fifos() do not wait
either. For this reason, it seems safe to remove the wait, fixing the
mentioned issue.
Fixes: 61929cf0169d ("tty: serial: Add 8250-core based omap driver")
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Matthias Schiffer <matthias.schiffer@ew.tq-group.com>
Link: https://lore.kernel.org/r/20221013112339.2540767-1-matthias.schiffer@ew.tq-group.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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There are cases where omap8250_set_mctrl() may get called after the
UART has already autoidled causing an asynchronous external abort.
This can happen on ttyport_open():
mem_serial_in from omap8250_set_mctrl+0x38/0xa0
omap8250_set_mctrl from uart_update_mctrl+0x4c/0x58
uart_update_mctrl from uart_dtr_rts+0x60/0xa8
uart_dtr_rts from tty_port_block_til_ready+0xd0/0x2a8
tty_port_block_til_ready from uart_open+0x14/0x1c
uart_open from ttyport_open+0x64/0x148
And on ttyport_close():
omap8250_set_mctrl from uart_update_mctrl+0x3c/0x48
uart_update_mctrl from uart_dtr_rts+0x54/0x9c
uart_dtr_rts from tty_port_shutdown+0x78/0x9c
tty_port_shutdown from tty_port_close+0x3c/0x74
tty_port_close from ttyport_close+0x40/0x58
It can also happen on disassociate_ctty() calling uart_shutdown()
that ends up calling omap8250_set_mctrl().
Let's fix the issue by adding missing PM runtime calls to
omap8250_set_mctrl(). To do this, we need to add __omap8250_set_mctrl()
that can be called from both omap8250_set_mctrl(), and from runtime PM
resume path when restoring the registers.
Fixes: 61929cf0169d ("tty: serial: Add 8250-core based omap driver")
Reported-by: Merlijn Wajer <merlijn@wizzup.org>
Reported-by: Romain Naour <romain.naour@smile.fr>
Reported-by: Ivaylo Dimitrov <ivo.g.dimitrov.75@gmail.com>
Tested-by: Ivaylo Dimitrov <ivo.g.dimitrov.75@gmail.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Depends-on: dd8088d5a896 ("PM: runtime: Add pm_runtime_resume_and_get to deal with usage counter")
Link: https://lore.kernel.org/r/20221024063613.25943-1-tony@atomide.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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RS485-enabled UART ports on TI Sitara SoCs with active-low polarity
exhibit a Transmit Enable glitch on ->set_termios():
omap8250_restore_regs(), which is called from omap_8250_set_termios(),
sets the TCRTLR bit in the MCR register and clears all other bits,
including RTS. If RTS uses active-low polarity, it is now asserted
for no reason.
The TCRTLR bit is subsequently cleared by writing up->mcr to the MCR
register. That variable is always zero, so the RTS bit is still cleared
(incorrectly so if RTS is active-high).
(up->mcr is not, as one might think, a cache of the MCR register's
current value. Rather, it only caches a single bit of that register,
the AFE bit. And it only does so if the UART supports the AFE bit,
which OMAP does not. For details see serial8250_do_set_termios() and
serial8250_do_set_mctrl().)
Finally at the end of omap8250_restore_regs(), the MCR register is
restored (and RTS deasserted) by a call to up->port.ops->set_mctrl()
(which equals serial8250_set_mctrl()) and serial8250_em485_stop_tx().
So there's an RTS glitch between setting TCRTLR and calling
serial8250_em485_stop_tx(). Avoid by using a read-modify-write
when setting TCRTLR.
While at it, drop a redundant initialization of up->mcr. As explained
above, the variable isn't used by the driver and it is already
initialized to zero because it is part of the static struct
serial8250_ports[] declared in 8250_core.c. (Static structs are
initialized to zero per section 6.7.8 nr. 10 of the C99 standard.)
Cc: Jan Kiszka <jan.kiszka@siemens.com>
Cc: Su Bao Cheng <baocheng.su@siemens.com>
Tested-by: Matthias Schiffer <matthias.schiffer@ew.tq-group.com>
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Link: https://lore.kernel.org/r/6554b0241a2c7fd50f32576fdbafed96709e11e8.1664278942.git.lukas@wunner.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Recent TI Sitara SoCs such as AM64/AM65 have gained the ability to
automatically assert RTS when data is transmitted, obviating the need
to emulate this functionality in software.
The feature is controlled through new DIR_EN and DIR_POL bits in the
Mode Definition Register 3. For details see page 8783 and 8890 of the
AM65 TRM: https://www.ti.com/lit/ug/spruid7e/spruid7e.pdf
Cc: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Cc: Su Bao Cheng <baocheng.su@siemens.com>
Cc: Vignesh Raghavendra <vigneshr@ti.com>
Cc: Jan Kiszka <jan.kiszka@siemens.com>
Cc: Bin Liu <b-liu@ti.com>
Tested-by: Zeng Chao <chao.zeng@siemens.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Link: https://lore.kernel.org/r/e9f25f5c9200a35d3162973c2b45d6b892cc9bf2.1665906869.git.lukas@wunner.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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When a UART port is newly registered, uart_configure_port() seeks to
deassert RS485 Transmit Enable by setting the RTS bit in port->mctrl.
However a number of UART drivers interpret a set RTS bit as *assertion*
instead of deassertion: Affected drivers include those using
serial8250_em485_config() (except 8250_bcm2835aux.c) and some using
mctrl_gpio (e.g. imx.c).
Since the interpretation of the RTS bit is driver-specific, it is not
suitable as a means to centrally deassert Transmit Enable in the serial
core. Instead, the serial core must call on drivers to deassert it in
their driver-specific way. One way to achieve that is to call
->rs485_config(). It implicitly deasserts Transmit Enable.
So amend uart_configure_port() and uart_resume_port() to invoke
uart_rs485_config(). That allows removing calls to uart_rs485_config()
from drivers' ->probe() hooks and declaring the function static.
Skip any invocation of ->set_mctrl() if RS485 is enabled. RS485 has no
hardware flow control, so the modem control lines are irrelevant and
need not be touched. When leaving RS485 mode, reset the modem control
lines to the state stored in port->mctrl. That way, UARTs which are
muxed between RS485 and RS232 transceivers drive the lines correctly
when switched to RS232. (serial8250_do_startup() historically raises
the OUT1 modem signal because otherwise interrupts are not signaled on
ancient PC UARTs, but I believe that no longer applies to modern,
RS485-capable UARTs and is thus safe to be skipped.)
imx.c modifies port->mctrl whenever Transmit Enable is asserted and
deasserted. Stop it from doing that so port->mctrl reflects the RS232
line state.
8250_omap.c deasserts Transmit Enable on ->runtime_resume() by calling
->set_mctrl(). Because that is now a no-op in RS485 mode, amend the
function to call serial8250_em485_stop_tx().
fsl_lpuart.c retrieves and applies the RS485 device tree properties
after registering the UART port. Because applying now happens on
registration in uart_configure_port(), move retrieval of the properties
ahead of uart_add_one_port().
Link: https://lore.kernel.org/all/20220329085050.311408-1-matthias.schiffer@ew.tq-group.com/
Link: https://lore.kernel.org/all/8f538a8903795f22f9acc94a9a31b03c9c4ccacb.camel@ginzinger.com/
Fixes: d3b3404df318 ("serial: Fix incorrect rs485 polarity on uart open")
Cc: stable@vger.kernel.org # v4.14+
Reported-by: Matthias Schiffer <matthias.schiffer@ew.tq-group.com>
Reported-by: Roosen Henri <Henri.Roosen@ginzinger.com>
Tested-by: Matthias Schiffer <matthias.schiffer@ew.tq-group.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Link: https://lore.kernel.org/r/2de36eba3fbe11278d5002e4e501afe0ceaca039.1663863805.git.lukas@wunner.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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uart_xmit_advance() provides a common way on how to advance
the Tx queue. Use it for the sake of unification and robustness.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20220909091258.68886-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty") into tty-next
We need the tty fixes and api additions in this branch.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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8250_omap uses em485, fill in rs485_supported accordingly. This makes
RS485 work with 8250_omap again, which was broken with the introduction
of the RS485 config sanitization.
Fixes: be2e2cb1d2819 ("serial: Sanitize rs485_struct")
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Matthias Schiffer <matthias.schiffer@ew.tq-group.com>
Link: https://lore.kernel.org/r/20220916110955.161099-1-matthias.schiffer@ew.tq-group.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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There should be no reason to adjust old ktermios which is going to get
discarded anyway.
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20220816115739.10928-7-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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DW flags address received as BIT(8) in LSR. In order to not lose that
on read, enlarge lsr_saved_flags to u16.
Adjust lsr/status variables and related call chains to use u16.
Technically, some of these type conversion would not be needed but it
doesn't hurt to be consistent.
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20220624204210.11112-2-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Having a generic UART_LCR_WLEN() macro and the tty_get_char_size()
helper, we can remove all those repeated switch-cases in drivers.
Cc: Laxman Dewangan <ldewangan@nvidia.com>
Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: Jonathan Hunter <jonathanh@nvidia.com>
Cc: linux-tegra@vger.kernel.org
Reviewed-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20220224095558.30929-2-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Commit b67e830d38fa ("serial: 8250: 8250_omap: Fix possible interrupt
storm on K3 SoCs") introduced fixup including a register read to
RX_LVL, however, we should be using word offset than byte offset
since our registers are on 4 byte boundary (port.regshift = 2) for
8250_omap.
Fixes: b67e830d38fa ("serial: 8250: 8250_omap: Fix possible interrupt storm on K3 SoCs")
Cc: stable <stable@vger.kernel.org>
Cc: Jan Kiszka <jan.kiszka@siemens.com>
Cc: Vignesh Raghavendra <vigneshr@ti.com>
Signed-off-by: Nishanth Menon <nm@ti.com>
Link: https://lore.kernel.org/r/20210903050550.29050-1-nm@ti.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Handle optional overrun-throttle-ms property as done for 8250_fsl in commit
6d7f677a2afa ("serial: 8250: Rate limit serial port rx interrupts during
input overruns"). This can be used to rate limit the UART interrupts on
noisy lines that end up producing messages like the following:
ttyS ttyS2: 4 input overrun(s)
At least on droid4, the multiplexed USB and UART port is left to UART mode
by the bootloader for a debug console, and if a USB charger is connected
on boot, we get noise on the UART until the PMIC related drivers for PHY
and charger are loaded.
With this patch and overrun-throttle-ms = <500> we avoid the extra rx
interrupts.
Cc: Carl Philipp Klemm <philipp@uvos.xyz>
Cc: Merlijn Wajer <merlijn@wizzup.org>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Sebastian Reichel <sre@kernel.org>
Cc: Vignesh Raghavendra <vigneshr@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Link: https://lore.kernel.org/r/20210727103533.51547-2-tony@atomide.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Don't populate the const array k3_soc_devices on the stack but instead it
static. Makes the object code smaller by 44 bytes:
Before:
text data bss dec hex filename
31628 5609 128 37365 91f5 drivers/tty/serial/8250/8250_omap.o
After:
text data bss dec hex filename
31520 5673 128 37321 91c9 drivers/tty/serial/8250/8250_omap.o
Reduction of 44 bytes
(gcc version 10.3.0)
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Link: https://lore.kernel.org/r/20210715140759.27244-1-colin.king@canonical.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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On K3 family of SoCs (which includes AM654 SoC), it is observed that RX
TIMEOUT is signalled after RX FIFO has been drained, in which case a
dummy read of RX FIFO is required to clear RX TIMEOUT condition.
Otherwise, this would lead to an interrupt storm.
Fix this by introducing UART_RX_TIMEOUT_QUIRK flag and doing a dummy
read in IRQ handler when RX TIMEOUT is reported with no data in RX FIFO.
Fixes: be70874498f3 ("serial: 8250_omap: Add support for AM654 UART controller")
Reported-by: Jan Kiszka <jan.kiszka@siemens.com>
Tested-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com>
Link: https://lore.kernel.org/r/20210622145704.11168-1-vigneshr@ti.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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This loop ends on -1 so the error message will never be printed.
Fixes: 4bcf59a5dea0 ("serial: 8250: 8250_omap: Account for data in flight during DMA teardown")
Reviewed-by: Alexander Sverdlin <alexander.sverdlin@gmail.com>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Link: https://lore.kernel.org/r/YIpd+kOpXKMpEXPf@mwanda
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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The uart_unlock_and_check_sysrq() helper can be used to defer processing
of sysrq until the interrupt handler has released the port lock and is
about to return.
Since commit 81e2073c175b ("genirq: Disable interrupts for force
threaded handlers") interrupt handlers that are not explicitly requested
as threaded are always called with interrupts disabled and there is no
need to save the interrupt state when taking the port lock.
Instead of adding another sysrq helper for when the interrupt state has
not needlessly been saved, drop the state parameter from
uart_unlock_and_check_sysrq() and update its callers to no longer
explicitly disable interrupts in their interrupt handlers.
Cc: Joel Stanley <joel@jms.id.au>
Cc: Andrew Jeffery <andrew@aj.id.au>
Cc: Andy Gross <agross@kernel.org>
Cc: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210416140557.25177-2-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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It has been observed that once per 300-1300 port openings the first
transmitted byte is being corrupted on AM3352 ("v" written to FIFO appeared
as "e" on the wire). It only happened if single byte has been transmitted
right after port open, which means, DMA is not used for this transfer and
the corruption never happened afterwards.
Therefore I've carefully re-read the MDR1 errata (link below), which says
"when accessing the MDR1 registers that causes a dummy under-run condition
that will freeze the UART in IrDA transmission. In UART mode, this may
corrupt the transferred data". Strictly speaking,
omap_8250_mdr1_errataset() performs a read access and if the value is the
same as should be written, exits without errata-recommended FIFO reset.
A brief check of the serial_omap_mdr1_errataset() from the competing
omap-serial driver showed it has no read access of MDR1. After removing the
read access from omap_8250_mdr1_errataset() the data corruption never
happened any more.
Link: https://www.ti.com/lit/er/sprz360i/sprz360i.pdf
Fixes: 61929cf0169d ("tty: serial: Add 8250-core based omap driver")
Cc: stable@vger.kernel.org
Signed-off-by: Alexander Sverdlin <alexander.sverdlin@gmail.com>
Link: https://lore.kernel.org/r/20201210055257.1053028-1-alexander.sverdlin@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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With commit 439c7183e5b9 ("serial: 8250: 8250_omap: Disable RX interrupt after DMA enable"),
below warning is seen with W=1 and CONFIG_SERIAL_8250_DMA is disabled:
drivers/tty/serial/8250/8250_omap.c:1199:42: warning: unused variable 'k3_soc_devices' [-Wunused-const-variable]
Fix this by moving the code using k3_soc_devices array to
omap_serial_fill_features_erratas() that handles other errata flags as
well.
Fixes: 439c7183e5b9 ("serial: 8250: 8250_omap: Disable RX interrupt after DMA enable")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com>
Link: https://lore.kernel.org/r/20201111112653.2710-2-vigneshr@ti.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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k3_soc_devices array is missing a sentinel entry which may result in out
of bounds access as reported by kernel KASAN.
Fix this by adding a sentinel entry.
Fixes: 439c7183e5b9 ("serial: 8250: 8250_omap: Disable RX interrupt after DMA enable")
Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com>
Link: https://lore.kernel.org/r/20201111112653.2710-1-vigneshr@ti.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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UARTs on TI SoCs prior to J7200 don't provide independent control over
RX FIFO not empty interrupt (RHR_IT) and RX timeout interrupt.
Starting with J7200 SoC, its possible to disable RHR_IT independent of
RX timeout interrupt using bit 2 of IER2 register. So disable RHR_IT
once RX DMA is started so as to avoid spurious interrupt being raised
when data is in the RX FIFO but is yet to be drained by DMA (a known
errata in older SoCs).
Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com>
Link: https://lore.kernel.org/r/20201029051930.7097-1-vigneshr@ti.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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