dw8250_handle_irq() calls serial8250_handle_irq_locked() with the port
lock held via guard(uart_port_lock_irqsave). The guard destructor is
plain uart_port_unlock_irqrestore(), so a SysRq character captured into
port->sysrq_ch by uart_prepare_sysrq_char() is dropped without ever
being dispatched to handle_sysrq().
This is the same regression pattern as in serial8250_handle_irq(),
introduced when 883c5a2bc9 ("serial: 8250_dw: Rework
dw8250_handle_irq() locking and IIR handling") moved the function to
the guard()-based locking scheme without using the sysrq-aware unlock
helper.
Switch to guard(uart_port_lock_check_sysrq_irqsave) so that captured
sysrq_ch is dispatched on scope exit, matching the fix in
serial8250_handle_irq().
Fixes: 883c5a2bc9 ("serial: 8250_dw: Rework dw8250_handle_irq() locking and IIR handling")
Cc: stable@vger.kernel.org
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Jacques Nilo <jnilo@free.fr>
Link: https://patch.msgid.link/ed56fcaf4af24e4ed011a7bce206e0182acb761c.1778675349.git.jnilo@free.fr
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
DW UART cannot write to LCR, DLL, and DLH while BUSY is asserted.
Existance of BUSY depends on uart_16550_compatible, if UART HW is
configured with it those registers can always be written.
There currently is dw8250_force_idle() which attempts to achieve
non-BUSY state by disabling FIFO, however, the solution is unreliable
when Rx keeps getting more and more characters.
Create a sequence of operations that ensures UART cannot keep BUSY
asserted indefinitely. The new sequence relies on enabling loopback mode
temporarily to prevent incoming Rx characters keeping UART BUSY.
Ensure no Tx in ongoing while the UART is switches into the loopback
mode (requires exporting serial8250_fifo_wait_for_lsr_thre() and adding
DMA Tx pause/resume functions).
According to tests performed by Adriana Nicolae <adriana@arista.com>,
simply disabling FIFO or clearing FIFOs only once does not always
ensure BUSY is deasserted but up to two tries may be needed. This could
be related to ongoing Rx of a character (a guess, not known for sure).
Therefore, retry FIFO clearing a few times (retry limit 4 is arbitrary
number but using, e.g., p->fifosize seems overly large). Tests
performed by others did not exhibit similar challenge but it does not
seem harmful to leave the FIFO clearing loop in place for all DW UARTs
with BUSY functionality.
Use the new dw8250_idle_enter/exit() to do divisor writes and LCR
writes. In case of plain LCR writes, opportunistically try to update
LCR first and only invoke dw8250_idle_enter() if the write did not
succeed (it has been observed that in practice most LCR writes do
succeed without complications).
This issue was first reported by qianfan Zhao who put lots of debugging
effort into understanding the solution space.
Fixes: c49436b657 ("serial: 8250_dw: Improve unwritable LCR workaround")
Fixes: 7d4008ebb1 ("tty: add a DesignWare 8250 driver")
Cc: stable <stable@kernel.org>
Reported-by: qianfan Zhao <qianfanguijin@163.com>
Link: https://lore.kernel.org/linux-serial/289bb78a-7509-1c5c-2923-a04ed3b6487d@163.com/
Reported-by: Adriana Nicolae <adriana@arista.com>
Link: https://lore.kernel.org/linux-serial/20250819182322.3451959-1-adriana@arista.com/
Reported-by: Bandal, Shankar <shankar.bandal@intel.com>
Tested-by: Bandal, Shankar <shankar.bandal@intel.com>
Tested-by: Murthy, Shanth <shanth.murthy@intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://patch.msgid.link/20260203171049.4353-8-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
INTC10EE UART can end up into an interrupt storm where it reports
IIR_NO_INT (0x1). If the storm happens during active UART operation, it
is promptly stopped by IIR value change due to Rx or Tx events.
However, when there is no activity, either due to idle serial line or
due to specific circumstances such as during shutdown that writes
IER=0, there is nothing to stop the storm.
During shutdown the storm is particularly problematic because
serial8250_do_shutdown() calls synchronize_irq() that will hang in
waiting for the storm to finish which never happens.
This problem can also result in triggering a warning:
irq 45: nobody cared (try booting with the "irqpoll" option)
[...snip...]
handlers:
serial8250_interrupt
Disabling IRQ #45
Normal means to reset interrupt status by reading LSR, MSR, USR, or RX
register do not result in the UART deasserting the IRQ.
Add a quirk to INTC10EE UARTs to enable Tx interrupts if UART's Tx is
currently empty and inactive. Rework IIR_NO_INT to keep track of the
number of consecutive IIR_NO_INT, and on fourth one perform the quirk.
Enabling Tx interrupts should change IIR value from IIR_NO_INT to
IIR_THRI which has been observed to stop the storm.
Fixes: e92fad0249 ("serial: 8250_dw: Add ACPI ID for Granite Rapids-D UART")
Cc: stable <stable@kernel.org>
Reported-by: Bandal, Shankar <shankar.bandal@intel.com>
Tested-by: Bandal, Shankar <shankar.bandal@intel.com>
Tested-by: Murthy, Shanth <shanth.murthy@intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://patch.msgid.link/20260203171049.4353-6-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
dw8250_handle_irq() takes port's lock multiple times with no good
reason to release it in between and calls serial8250_handle_irq()
that also takes port's lock.
Take port's lock only once in dw8250_handle_irq() and use
serial8250_handle_irq_locked() to avoid releasing port's lock in
between.
As IIR_NO_INT check in serial8250_handle_irq() was outside of port's
lock, it has to be done already in dw8250_handle_irq().
DW UART can, in addition to IIR_NO_INT, report BUSY_DETECT (0x7) which
collided with the IIR_NO_INT (0x1) check in serial8250_handle_irq()
(because & is used instead of ==) meaning that no other work is done by
serial8250_handle_irq() during an BUSY_DETECT interrupt.
This allows reorganizing code in dw8250_handle_irq() to do both
IIR_NO_INT and BUSY_DETECT handling right at the start simplifying
the logic.
Tested-by: Bandal, Shankar <shankar.bandal@intel.com>
Tested-by: Murthy, Shanth <shanth.murthy@intel.com>
Cc: stable <stable@kernel.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://patch.msgid.link/20260203171049.4353-5-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When DW UART is configured with BUSY flag, LCR writes may not always
succeed which can make any LCR write complex and very expensive.
Performing write directly can trigger IRQ and the driver has to perform
complex and distruptive sequence while retrying the write.
Therefore, it's better to avoid doing LCR write that would not change
the value of the LCR register. Add LCR write avoidance code into the
8250_dw driver's .serial_out() functions.
Reported-by: Bandal, Shankar <shankar.bandal@intel.com>
Tested-by: Bandal, Shankar <shankar.bandal@intel.com>
Tested-by: Murthy, Shanth <shanth.murthy@intel.com>
Cc: stable <stable@kernel.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://patch.msgid.link/20260203171049.4353-3-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Move pm_runtime_set_active() call earlier in probe to simplify error
handling and add proper error checking to ensure the device is marked
as active before any runtime PM operations can occur.
Additionally, replace the const struct dev_pm_ops declaration with
_DEFINE_DEV_PM_OPS macro for better consistency with modern kernel PM
patterns.
Signed-off-by: Artem Shimko <a.shimko.dev@gmail.com>
Link: https://patch.msgid.link/20251104145433.2316165-3-a.shimko.dev@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add error checking for clk_prepare_enable() calls in
dw8250_runtime_resume(). Currently if either clock fails to enable,
the function returns success while leaving clocks in inconsistent state.
This change implements comprehensive error handling by checking the return
values of both clk_prepare_enable() calls. If the second clock enable
operation fails after the first clock has already been successfully
enabled, the code now properly cleans up by disabling and unpreparing
the first clock before returning. The error code is then propagated to
the caller, ensuring that clock enable failures are properly reported
rather than being silently ignored.
Signed-off-by: Artem Shimko <a.shimko.dev@gmail.com>
Link: https://patch.msgid.link/20251104145433.2316165-2-a.shimko.dev@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Currently if a user enqueue a work item using schedule_delayed_work() the
used wq is "system_wq" (per-cpu wq) while queue_delayed_work() use
WORK_CPU_UNBOUND (used when a cpu is not specified). The same applies to
schedule_work() that is using system_wq and queue_work(), that makes use
again of WORK_CPU_UNBOUND.
This lack of consistentcy cannot be addressed without refactoring the API.
This patch continues the effort to refactor worqueue APIs, which has begun
with the change introducing new workqueues and a new alloc_workqueue flag:
commit 128ea9f6cc ("workqueue: Add system_percpu_wq and system_dfl_wq")
commit 930c2ea566 ("workqueue: Add new WQ_PERCPU flag")
system_dfl_wq should be the default workqueue so as not to enforce
locality constraints for random work whenever it's not required.
The old system_unbound_wq will be kept for a few release cycles.
Suggested-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Marco Crivellari <marco.crivellari@suse.com>
Link: https://patch.msgid.link/20251104105446.110884-1-marco.crivellari@suse.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Check the return value of reset_control_deassert() in the probe
function to prevent continuing probe when reset deassertion fails.
Previously, reset_control_deassert() was called without checking its
return value, which could lead to probe continuing even when the
device reset wasn't properly deasserted.
The fix checks the return value and returns an error with dev_err_probe()
if reset deassertion fails, providing better error handling and
diagnostics.
Fixes: acbdad8dd1 ("serial: 8250_dw: simplify optional reset handling")
Cc: stable <stable@kernel.org>
Signed-off-by: Artem Shimko <a.shimko.dev@gmail.com>
Link: https://patch.msgid.link/20251019095131.252848-1-a.shimko.dev@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
There is a spelling mistake of 'notifer' in the comment which
should be 'notifier'.
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: WangYuli <wangyuli@uniontech.com>
Link: https://lore.kernel.org/r/BD4804BF4FBA1648+20250722073431.21983-6-wangyuli@uniontech.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
uart_port::{serial_in,serial_out} (and plat_serial8250_port::* likewise)
historically use:
* 'unsigned int' for 32-bit register values in reads and writes, and
* 'int' for offsets.
Make them sane such that:
* 'u32' is used for register values, and
* 'unsigned int' is used for offsets.
While at it, name hooks' parameters, so it is clear what is what.
Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Paul Cercueil <paul@crapouillou.net>
Cc: Vladimir Zapolskiy <vz@mleia.com>
Cc: Kunihiko Hayashi <hayashi.kunihiko@socionext.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20250611100319.186924-9-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
8250 DesignWare driver uses a few custom implementations of the serial_out().
These implementations are carefully made to avoid infinite loops. But this is
not obvious from looking at the code. Comment the possible corner cases in
the respective functions.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20250317094021.1201512-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
There are serial_port_in/out() helpers to be used instead of direct
p->serial_in/out(). Use them in various 8250 drivers.
Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org>
Cc: "Ilpo Järvinen" <ilpo.jarvinen@linux.intel.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
--
[v2]
* Use serial_port_in/out() and not serial_in/out() [Andy]
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> # 8250_dw
Link: https://lore.kernel.org/r/20250317070046.24386-28-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Not all the cases provide the driver data, that is represented by
an object instance of struct dw8250_platform_data. Id est the change
missed the case when the driver is instantiated via board files as
pure platform driver. Fix this by calling dw8250_quirks() conditionally.
This will require splitting dw8250_setup_dma_filter() out of dw8250_quirks().
Also make sure IRQ handler won't crash, it also requires driver data
to be present.
Fixes: bfd3d4a40f ("serial: 8250_dw: Drop unneeded NULL checks in dw8250_quirks()")
Reported-by: kernel test robot <oliver.sang@intel.com>
Closes: https://lore.kernel.org/oe-lkp/202502121529.f7e65d49-lkp@intel.com
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20250212115952.2312444-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Since platform data is being provided for all supported hardware,
no need to NULL check for it. Drop unneeded checks.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20250203121456.3182891-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
SG2044 relys on an internal divisor when calculating bitrate, which
means a wrong clock for the most common bitrates. So add a quirk for
this uart device to skip the set rate call and only relys on the
internal UART divisor.
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Inochi Amaoto <inochiama@gmail.com>
Link: https://lore.kernel.org/r/20241024062105.782330-4-inochiama@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
After commit 0edb555a65 ("platform: Make platform_driver::remove()
return void") .remove() is (again) the right callback to implement for
platform drivers.
Convert all platform drivers below drivers/tty/serial to use .remove(),
with the eventual goal to drop struct platform_driver::remove_new(). As
.remove() and .remove_new() have the same prototypes, conversion is done
by just changing the structure member name in the driver initializer.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com>
Link: https://lore.kernel.org/r/20241007205803.444994-7-u.kleine-koenig@baylibre.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Some SoCs like StarFive JH7110 require two or more resets.
So change to use the reset array API to get resets.
Signed-off-by: Hal Feng <hal.feng@starfivetech.com>
Link: https://lore.kernel.org/r/20240604084729.57239-3-hal.feng@starfivetech.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This reverts commit d9666dfb31.
The container of the struct dw8250_port_data is private to the actual
driver. In particular, 8250_lpss and 8250_dw use different data types
that are assigned to the UART port private_data. Hence, it must not
be used outside the specific driver.
Fix the mistake made in the past by moving the respective definitions
to the specific driver.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20240514190730.2787071-3-andriy.shevchenko@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The container of the struct dw8250_port_data is private to the actual
driver. In particular, 8250_lpss and 8250_dw use different data types
that are assigned to the UART port private_data. Hence, it must not
be used outside the specific driver.
Currently the only cpr_val is required by the common code, make it
be available via struct dw8250_port_data.
This fixes the UART breakage on Intel Galileo boards.
Fixes: 593dea000b ("serial: 8250: dw: Allow to use a fallback CPR value if not synthesized")
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20240514190730.2787071-2-andriy.shevchenko@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
We want the tty fixes in here as well, and it resolves a merge conflict
in:
drivers/tty/serial/serial_core.c
as well.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
dw8250_serial_inq() uses unsigned int variable to store 8-bit value.
Due to that it needs a cast which can be avoided by switching to use
u8 instead of unsigned int.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20240412173937.187442-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit e5d6bd25f9 ("serial: 8250_dw: Do not reclock if already at
correct rate") breaks the dw UARTs on Intel Bay Trail (BYT) and
Cherry Trail (CHT) SoCs.
Before this change the RTL8732BS Bluetooth HCI which is found
connected over the dw UART on both BYT and CHT boards works properly:
Bluetooth: hci0: RTL: examining hci_ver=06 hci_rev=000b lmp_ver=06 lmp_subver=8723
Bluetooth: hci0: RTL: rom_version status=0 version=1
Bluetooth: hci0: RTL: loading rtl_bt/rtl8723bs_fw.bin
Bluetooth: hci0: RTL: loading rtl_bt/rtl8723bs_config-OBDA8723.bin
Bluetooth: hci0: RTL: cfg_sz 64, total sz 24508
Bluetooth: hci0: RTL: fw version 0x365d462e
where as after this change probing it fails:
Bluetooth: hci0: RTL: examining hci_ver=06 hci_rev=000b lmp_ver=06 lmp_subver=8723
Bluetooth: hci0: RTL: rom_version status=0 version=1
Bluetooth: hci0: RTL: loading rtl_bt/rtl8723bs_fw.bin
Bluetooth: hci0: RTL: loading rtl_bt/rtl8723bs_config-OBDA8723.bin
Bluetooth: hci0: RTL: cfg_sz 64, total sz 24508
Bluetooth: hci0: command 0xfc20 tx timeout
Bluetooth: hci0: RTL: download fw command failed (-110)
Revert the changes to fix this regression.
Fixes: e5d6bd25f9 ("serial: 8250_dw: Do not reclock if already at correct rate")
Cc: stable@vger.kernel.org
Cc: Peter Collingbourne <pcc@google.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Peter Collingbourne <pcc@google.com>
Link: https://lore.kernel.org/r/20240317214123.34482-1-hdegoede@redhat.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Here is the big set of TTY/Serial driver updates and cleanups for
6.9-rc1. Included in here are:
- more tty cleanups from Jiri
- loads of 8250 driver cleanups from Andy
- max310x driver updates
- samsung serial driver updates
- uart_prepare_sysrq_char() updates for many drivers
- platform driver remove callback void cleanups
- stm32 driver updates
- other small tty/serial driver updates
All of these have been in linux-next for a long time with no reported
issues.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'tty-6.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty
Pull tty / serial driver updates from Greg KH:
"Here is the big set of TTY/Serial driver updates and cleanups for
6.9-rc1. Included in here are:
- more tty cleanups from Jiri
- loads of 8250 driver cleanups from Andy
- max310x driver updates
- samsung serial driver updates
- uart_prepare_sysrq_char() updates for many drivers
- platform driver remove callback void cleanups
- stm32 driver updates
- other small tty/serial driver updates
All of these have been in linux-next for a long time with no reported
issues"
* tag 'tty-6.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (199 commits)
dt-bindings: serial: stm32: add power-domains property
serial: 8250_dw: Replace ACPI device check by a quirk
serial: Lock console when calling into driver before registration
serial: 8250_uniphier: Switch to use uart_read_port_properties()
serial: 8250_tegra: Switch to use uart_read_port_properties()
serial: 8250_pxa: Switch to use uart_read_port_properties()
serial: 8250_omap: Switch to use uart_read_port_properties()
serial: 8250_of: Switch to use uart_read_port_properties()
serial: 8250_lpc18xx: Switch to use uart_read_port_properties()
serial: 8250_ingenic: Switch to use uart_read_port_properties()
serial: 8250_dw: Switch to use uart_read_port_properties()
serial: 8250_bcm7271: Switch to use uart_read_port_properties()
serial: 8250_bcm2835aux: Switch to use uart_read_port_properties()
serial: 8250_aspeed_vuart: Switch to use uart_read_port_properties()
serial: port: Introduce a common helper to read properties
serial: core: Add UPIO_UNKNOWN constant for unknown port type
serial: core: Move struct uart_port::quirks closer to possible values
serial: sh-sci: Call sci_serial_{in,out}() directly
serial: core: only stop transmit when HW fifo is empty
serial: pch: Use uart_prepare_sysrq_char().
...
Since we have now a common helper to read port properties
use it instead of sparse home grown solution.
Reviewed-by: Andi Shyti <andi.shyti@linux.intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20240304123035.758700-8-andriy.shevchenko@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When userspace opens the console, we call set_termios() passing a
termios with the console's configured baud rate. Currently this causes
dw8250_set_termios() to disable and then re-enable the UART clock at
the same frequency as it was originally. This can cause corruption
of any concurrent console output. Fix it by skipping the reclocking
if we are already at the correct rate.
Signed-off-by: Peter Collingbourne <pcc@google.com>
Fixes: 4e26b134bd ("serial: 8250_dw: clock rate handling for all ACPI platforms")
Cc: stable@vger.kernel.org
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20240222192635.1050502-1-pcc@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Instead of silently giving up, at least tell what the problem is.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20240222111922.2016122-2-u.kleine-koenig@pengutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Granite Rapids-D has an additional UART that is enumerated via ACPI.
Add ACPI ID for it.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: stable <stable@kernel.org>
Link: https://lore.kernel.org/r/20231205195524.2705965-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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>
Use devm_clk_get_optional_enabled() to simplify the code.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Andi Shyti <andi.shyti@linux.intel.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20230919195513.3197930-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Link: https://lore.kernel.org/r/20230914183831.587273-9-john.ogness@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When there's no irq(this can be due to various reasons, for example,
no irq from HW support, or we just want to use poll solution, and so
on), falling back to poll is still better than no support at all.
Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Link: https://lore.kernel.org/r/20230806092056.2467-3-jszhang@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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>
Here is the big set of tty and serial driver changes for 6.0-rc1.
It was delayed from last week as I wanted to make sure the last commit
here got some good testing in linux-next and elsewhere as it seemed to
show up only late in testing for some reason.
Nothing major here, just lots of cleanups from Jiri and Ilpo to make the
tty core cleaner (Jiri) and the rs485 code simpler to use (Ilpo). Also
included in here is the obligatory n_gsm updates from Daniel Starke and
lots of tiny driver updates and minor fixes and tweaks for other smaller
serial drivers.
Full details are in the shortlog.
All of these have been in linux-next for a while with no reported
problems.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'tty-6.0-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty
Pull tty / serial driver updates from Greg KH:
"Here is the big set of tty and serial driver changes for 6.0-rc1.
It was delayed from last week as I wanted to make sure the last commit
here got some good testing in linux-next and elsewhere as it seemed to
show up only late in testing for some reason.
Nothing major here, just lots of cleanups from Jiri and Ilpo to make
the tty core cleaner (Jiri) and the rs485 code simpler to use (Ilpo).
Also included in here is the obligatory n_gsm updates from Daniel
Starke and lots of tiny driver updates and minor fixes and tweaks for
other smaller serial drivers.
All of these have been in linux-next for a while with no reported
problems"
* tag 'tty-6.0-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (186 commits)
tty: serial: qcom-geni-serial: Fix %lu -> %u in print statements
tty: amiserial: Fix comment typo
tty: serial: document uart_get_console()
tty: serial: serial_core, reformat kernel-doc for functions
Documentation: serial: link uart_ops properly
Documentation: serial: move GPIO kernel-doc to the functions
Documentation: serial: dedup kernel-doc for uart functions
Documentation: serial: move uart_ops documentation to the struct
dt-bindings: serial: snps-dw-apb-uart: Document Rockchip RV1126
serial: mvebu-uart: uart2 error bits clearing
tty: serial: fsl_lpuart: correct the count of break characters
serial: stm32: make info structs static to avoid sparse warnings
serial: fsl_lpuart: zero out parity bit in CS7 mode
tty: serial: qcom-geni-serial: Fix get_clk_div_rate() which otherwise could return a sub-optimal clock rate.
serial: 8250_bcm2835aux: Add missing clk_disable_unprepare()
tty: vt: initialize unicode screen buffer
serial: remove VR41XX serial driver
serial: 8250: lpc18xx: Remove redundant sanity check for RS485 flags
serial: 8250_dwlib: remove redundant sanity check for RS485 flags
dt_bindings: rs485: Correct delay values
...
With PSLVERR_RESP_EN parameter set to 1, the device generates an error
response when an attempt to read an empty RBR with FIFO enabled.
This happens when LCR writes are ignored when UART is busy.
dw8250_check_lcr() in retries to update LCR, invokes dw8250_force_idle()
to clear and reset FIFO and eventually reads UART_RX causing the error.
Avoid this by not reading RBR/UART_RX when no data is available.
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: VAMSHI GAJJELA <vamshigajjela@google.com>
Link: https://lore.kernel.org/r/20220713131722.2316829-1-vamshigajjela@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
As per RZ/N1 peripheral user manual(r01uh0752ej0100-rzn1-peripheral.pdf)
rev 1.0.0 Mar,2019, the value for 8_WORD_BURST is 4(b2,b1=2’b10).
This patch fixes the macro as per the user manual.
Fixes: aa63d786ce ("serial: 8250: dw: Add support for DMA flow controlling devices")
Reviewed-by: Phil Edworthy <phil.edworthy@renesas.com>
Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
Link: https://lore.kernel.org/r/20220630083909.4294-1-biju.das.jz@bp.renesas.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Place dw8250_serial_out() before dw8250_serial_out38x() so that it can
be called from dw8250_serial_out38x() to do the actual write.
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20220628134234.53771-2-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Drop CONFIG_PM and CONFIG_PM_SLEEP ifdeffery while converting dw8250_pm_ops
to use new PM macros. Since we are using runtime PM, wrap dw8250_pm_ops into
pm_ptr().
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20220630100507.31113-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
For the sake of better maintenance, sort included headers alphabetically.
While at it, split the serial group of headers which makes clear the
subsystem the driver belongs to.
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20220630093816.28271-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Accessing LSR requires port lock because it mutates lsr_saved_flags
in serial_lsr_in().
Fixes: 197eb5c416 ("serial: 8250_dw: Use serial_lsr_in() in dw8250_handle_irq()")
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/c5879db7-bee9-93f-526e-872a292442@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit ffd381445e ("serial: 8250: dw: Move the USR register to pdata")
caused NULL-pointer dereference when booting with ACPI by unconditional
usage of the recently added pdata.
In order to fix that and prevent similar issues in future, hook the
default version of this structure in dw8250_acpi_match table.
While at it, sort all entries alphabetically.
Fixes: ffd381445e ("serial: 8250: dw: Move the USR register to pdata")
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Marcin Wojtas <mw@semihalf.com>
Link: https://lore.kernel.org/r/20220620121046.1307412-1-mw@semihalf.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Make sure LSR flags are preserved in dw8250_tx_wait_empty(). This
function is called from a low-level out function and therefore cannot
call serial_lsr_in() as it would lead to infinite recursion.
It is borderline if the flags need to be saved here at all since this
code relates to writing LCR register which usually implies no important
characters should be arriving.
Fixes: 914eaf935e ("serial: 8250_dw: Allow TX FIFO to drain before writing to UART_LCR")
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20220608095431.18376-7-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
dw8250_handle_irq() reads LSR under a few conditions, convert both to
use serial_lsr_in() in order to preserve LSR flags properly across
reads.
Fixes: 424d79183a ("serial: 8250_dw: Avoid "too much work" from bogus rx timeout interrupt")
Fixes: aa63d786ce ("serial: 8250: dw: Add support for DMA flow controlling devices")
Cc: Douglas Anderson <dianders@chromium.org>
Cc: Phil Edworthy <phil.edworthy@renesas.com>
Cc: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20220608095431.18376-6-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Slightly simplify ->probe() and drop a few goto labels by using
devm_add_action_or_reset() for clock and reset cleanup.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20220509172129.37770-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The of_irq.h and of_platform.h are not used by the driver. On the
other hand, the mod_devicetable.h missed. Drop the former two and
add the latter one.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20220509161911.37164-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Jacques Nilo