serial: imx: Ensure that imx_uart_rs485_config() is called with enabled clock

There are register accesses in the function imx_uart_rs485_config(). The
clock must be enabled for these accesses. This

serial: imx: Ensure that imx_uart_rs485_config() is called with enabled clock

There are register accesses in the function imx_uart_rs485_config(). The
clock must be enabled for these accesses. This was ensured by calling it
via the function uart_rs485_config() in the probe() function within the
range where the clock is enabled. With the commit 7c7f9bc986e6 ("serial:
Deassert Transmit Enable on probe in driver-specific way") it was removed
from the probe() function and is now only called through the function
uart_add_one_port() which is located at the end of the probe() function.
But the clock is already switched off in this area. To ensure that the
clock is enabled during register access, move the disabling of the clock
to the very end of the probe() function. To avoid leaking enabled clocks
on error also add an error path for exiting with disabling the clock.

Fixes: 7c7f9bc986e6 ("serial: Deassert Transmit Enable on probe in driver-specific way")
Cc: stable <stable@kernel.org>
Signed-off-by: Christoph Niedermaier <cniedermaier@dh-electronics.com>
Reviewed-by: Lukas Wunner <lukas@wunner.de>
Link: https://lore.kernel.org/r/20231226113647.39376-1-cniedermaier@dh-electronics.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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serial: imx: Correct clock error message in function probe()

Correct the clock error message by changing the clock name.

Fixes: 1e512d45332b ("serial: imx: add error messages when .probe fails")
Si

serial: imx: Correct clock error message in function probe()

Correct the clock error message by changing the clock name.

Fixes: 1e512d45332b ("serial: imx: add error messages when .probe fails")
Signed-off-by: Christoph Niedermaier <cniedermaier@dh-electronics.com>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20231224093209.2612-1-cniedermaier@dh-electronics.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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serial: imx: fix tx statemachine deadlock

When using the serial port as RS485 port, the tx statemachine is used to
control the RTS pin to drive the RS485 transceiver TX_EN pin. When the
TTY port is

serial: imx: fix tx statemachine deadlock

When using the serial port as RS485 port, the tx statemachine is used to
control the RTS pin to drive the RS485 transceiver TX_EN pin. When the
TTY port is closed in the middle of a transmission (for instance during
userland application crash), imx_uart_shutdown disables the interface
and disables the Transmission Complete interrupt. afer that,
imx_uart_stop_tx bails on an incomplete transmission, to be retriggered
by the TC interrupt. This interrupt is disabled and therefore the tx
statemachine never transitions out of SEND. The statemachine is in
deadlock now, and the TX_EN remains low, making the interface useless.

imx_uart_stop_tx now checks for incomplete transmission AND whether TC
interrupts are enabled before bailing to be retriggered. This makes sure
the state machine handling is reached, and is properly set to
WAIT_AFTER_SEND.

Fixes: cb1a60923609 ("serial: imx: implement rts delaying for rs485")
Signed-off-by: Paul Geurts <paul_geurts@live.nl>
Tested-by: Rasmus Villemoes <rasmus.villemoes@prevas.dk>
Tested-by: Eberhard Stoll <eberhard.stoll@gmx.de>
Link: https://lore.kernel.org/r/AM0PR09MB26758F651BC1B742EB45775995B8A@AM0PR09MB2675.eurprd09.prod.outlook.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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serial: imx: convert not to use dma_request_slave_channel()

dma_request_slave_channel() is deprecated. dma_request_chan() should
be used directly instead.

Switch to the preferred function and updat

serial: imx: convert not to use dma_request_slave_channel()

dma_request_slave_channel() is deprecated. dma_request_chan() should
be used directly instead.

Switch to the preferred function and update the error handling accordingly.

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Link: https://lore.kernel.org/r/a46b493c6b5cfa09417e3e138e304fd01b61e748.1700410346.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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serial: imx: Convert to platform remove callback returning void

The .remove() callback for a platform driver returns an int which makes
many driver authors wrongly assume it's possible to do error h

serial: imx: Convert to platform remove callback returning void

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>
Link: https://lore.kernel.org/r/20231110152927.70601-18-u.kleine-koenig@pengutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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Merge branch 'for-6.8/amd-sfh' into for-linus

- addition of new interfaces to export User presence information and
Ambient light from amd-sfh to other drivers within the kernel (Basavaraj
Natika

Merge branch 'for-6.8/amd-sfh' into for-linus

- addition of new interfaces to export User presence information and
Ambient light from amd-sfh to other drivers within the kernel (Basavaraj
Natikar)

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Merge drm/drm-next into drm-misc-next

Let's kickstart the v6.8 release cycle.

Signed-off-by: Maxime Ripard <mripard@kernel.org>

Merge drm/drm-next into drm-intel-gt-next

Work that needs to land in drm-intel-gt-next depends on two patches only
present in drm-intel-next, absence of which is causing a merge conflict:

3b918f4

Merge drm/drm-next into drm-intel-gt-next

Work that needs to land in drm-intel-gt-next depends on two patches only
present in drm-intel-next, absence of which is causing a merge conflict:

3b918f4f0c8b ("drm/i915/pxp: Optimize GET_PARAM:PXP_STATUS")
ac765b7018f6 ("drm/i915/pxp/mtl: intel_pxp_init_hw needs runtime-pm inside pm-complete")

Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>

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Merge branch 'tip/perf/urgent'

Avoid conflicts, base on fixes.

Signed-off-by: Peter Zijlstra <peterz@infradead.org>

Merge branch 'next' into for-linus

Prepare input updates for 6.7 merge window.

Merge tag 'tty-6.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

Pull tty and serial updates from Greg KH:
"Here is the big set of tty/serial driver changes for 6.7-rc1. Included

Merge tag 'tty-6.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

Pull tty and serial updates from Greg KH:
"Here is the big set of tty/serial driver changes for 6.7-rc1. Included
in here are:

- console/vgacon cleanups and removals from Arnd

- tty core and n_tty cleanups from Jiri

- lots of 8250 driver updates and cleanups

- sc16is7xx serial driver updates

- dt binding updates

- first set of port lock wrapers from Thomas for the printk fixes
coming in future releases

- other small serial and tty core cleanups and updates

All of these have been in linux-next for a while with no reported
issues"

* tag 'tty-6.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (193 commits)
serdev: Replace custom code with device_match_acpi_handle()
serdev: Simplify devm_serdev_device_open() function
serdev: Make use of device_set_node()
tty: n_gsm: add copyright Siemens Mobility GmbH
tty: n_gsm: fix race condition in status line change on dead connections
serial: core: Fix runtime PM handling for pending tx
vgacon: fix mips/sibyte build regression
dt-bindings: serial: drop unsupported samsung bindings
tty: serial: samsung: drop earlycon support for unsupported platforms
tty: 8250: Add note for PX-835
tty: 8250: Fix IS-200 PCI ID comment
tty: 8250: Add Brainboxes Oxford Semiconductor-based quirks
tty: 8250: Add support for Intashield IX cards
tty: 8250: Add support for additional Brainboxes PX cards
tty: 8250: Fix up PX-803/PX-857
tty: 8250: Fix port count of PX-257
tty: 8250: Add support for Intashield IS-100
tty: 8250: Add support for Brainboxes UP cards
tty: 8250: Add support for additional Brainboxes UC cards
tty: 8250: Remove UC-257 and UC-431
...

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Merge branch 'linus' into smp/core

Pull in upstream to get the fixes so depending changes can be applied.

Merge drm/drm-next into drm-misc-next

Updating drm-misc-next to the state of Linux v6.6-rc2.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>

serial: imx: Put DMA enabled UART in separate lock subclass

Lockdep complains about possible circular locking dependencies when the
i.MX SDMA driver issues console messages under its spinlock. While

serial: imx: Put DMA enabled UART in separate lock subclass

Lockdep complains about possible circular locking dependencies when the
i.MX SDMA driver issues console messages under its spinlock. While the
SDMA driver calls back into the UART when issuing a message, the i.MX
UART driver will never call back into the SDMA driver for this UART,
because DMA is explicitly not used for UARTs providing the console.

To avoid the lockdep warnings put the UART port lock for console devices
into a separate subclass.

This fixes possible deadlock warnings like the following which was
provoked by adding a printk to the i.MX SDMA driver at a place where the
driver holds its spinlock.

======================================================
WARNING: possible circular locking dependency detected
6.6.0-rc3-00045-g517852be693b-dirty #110 Not tainted
------------------------------------------------------
swapper/0/0 is trying to acquire lock:
c1818e04 (console_owner){-...}-{0:0}, at: console_flush_all+0x1c4/0x634

but task is already holding lock:
c44649e0 (&vc->lock){-...}-{3:3}, at: sdma_int_handler+0xc4/0x368

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #2 (&vc->lock){-...}-{3:3}:
_raw_spin_lock_irqsave+0x4c/0x68
sdma_prep_dma_cyclic+0x1a8/0x21c
imx_uart_startup+0x44c/0x5d4
uart_startup+0x120/0x2b0
uart_port_activate+0x44/0x98
tty_port_open+0x80/0xd0
uart_open+0x18/0x20
tty_open+0x120/0x664
chrdev_open+0xc0/0x214
do_dentry_open+0x1d0/0x544
path_openat+0xbb0/0xea0
do_filp_open+0x5c/0xd4
do_sys_openat2+0xb8/0xf0
sys_openat+0x8c/0xd8
ret_fast_syscall+0x0/0x1c

-> #1 (&port_lock_key){-.-.}-{3:3}:
_raw_spin_lock_irqsave+0x4c/0x68
imx_uart_console_write+0x164/0x1a0
console_flush_all+0x220/0x634
console_unlock+0x64/0x164
vprintk_emit+0xb0/0x390
vprintk_default+0x24/0x2c
_printk+0x2c/0x5c
register_console+0x244/0x478
serial_core_register_port+0x5c4/0x618
imx_uart_probe+0x4e0/0x7d4
platform_probe+0x58/0xb0
really_probe+0xc4/0x2e0
__driver_probe_device+0x84/0x1a0
driver_probe_device+0x2c/0x108
__driver_attach+0x94/0x17c
bus_for_each_dev+0x7c/0xd0
bus_add_driver+0xc4/0x1cc
driver_register+0x7c/0x114
imx_uart_init+0x20/0x40
do_one_initcall+0x7c/0x3c4
kernel_init_freeable+0x17c/0x228
kernel_init+0x14/0x140
ret_from_fork+0x14/0x24

-> #0 (console_owner){-...}-{0:0}:
__lock_acquire+0x14b0/0x29a0
lock_acquire.part.0+0xb4/0x264
console_flush_all+0x20c/0x634
console_unlock+0x64/0x164
vprintk_emit+0xb0/0x390
vprintk_default+0x24/0x2c
_printk+0x2c/0x5c
sdma_int_handler+0xcc/0x368
__handle_irq_event_percpu+0x94/0x2d0
handle_irq_event+0x38/0xd0
handle_fasteoi_irq+0x98/0x248
handle_irq_desc+0x1c/0x2c
gic_handle_irq+0x6c/0x90
generic_handle_arch_irq+0x2c/0x64
__irq_svc+0x90/0xbc
cpuidle_enter_state+0x1a0/0x4f4
cpuidle_enter+0x30/0x40
do_idle+0x210/0x2b4
cpu_startup_entry+0x28/0x2c
rest_init+0xd0/0x184
arch_post_acpi_subsys_init+0x0/0x8

other info that might help us debug this:

Chain exists of:
console_owner --> &port_lock_key --> &vc->lock

Possible unsafe locking scenario:

CPU0 CPU1
---- ----
lock(&vc->lock);
lock(&port_lock_key);
lock(&vc->lock);
lock(console_owner);

*** DEADLOCK ***

3 locks held by swapper/0/0:
#0: c44649e0 (&vc->lock){-...}-{3:3}, at: sdma_int_handler+0xc4/0x368
#1: c1818d50 (console_lock){+.+.}-{0:0}, at: vprintk_default+0x24/0x2c
#2: c1818d08 (console_srcu){....}-{0:0}, at: console_flush_all+0x44/0x634

stack backtrace:
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 6.6.0-rc3-00045-g517852be693b-dirty #110
Hardware name: Freescale i.MX6 Quad/DualLite (Device Tree)
unwind_backtrace from show_stack+0x10/0x14
show_stack from dump_stack_lvl+0x60/0x90
dump_stack_lvl from check_noncircular+0x184/0x1b8
check_noncircular from __lock_acquire+0x14b0/0x29a0
__lock_acquire from lock_acquire.part.0+0xb4/0x264
lock_acquire.part.0 from console_flush_all+0x20c/0x634
console_flush_all from console_unlock+0x64/0x164
console_unlock from vprintk_emit+0xb0/0x390
vprintk_emit from vprintk_default+0x24/0x2c
vprintk_default from _printk+0x2c/0x5c
_printk from sdma_int_handler+0xcc/0x368
sdma_int_handler from __handle_irq_event_percpu+0x94/0x2d0
__handle_irq_event_percpu from handle_irq_event+0x38/0xd0
handle_irq_event from handle_fasteoi_irq+0x98/0x248
handle_fasteoi_irq from handle_irq_desc+0x1c/0x2c
handle_irq_desc from gic_handle_irq+0x6c/0x90
gic_handle_irq from generic_handle_arch_irq+0x2c/0x64
generic_handle_arch_irq from __irq_svc+0x90/0xbc
Exception stack(0xc1801ee8 to 0xc1801f30)
1ee0: ffffffff ffffffff 00000001 00030349 00000000 00000012
1f00: 00000000 d7e45f4b 00000012 00000000 d7e16d63 c1810828 00000000 c1801f38
1f20: c108125c c1081260 60010013 ffffffff
__irq_svc from cpuidle_enter_state+0x1a0/0x4f4
cpuidle_enter_state from cpuidle_enter+0x30/0x40
cpuidle_enter from do_idle+0x210/0x2b4
do_idle from cpu_startup_entry+0x28/0x2c
cpu_startup_entry from rest_init+0xd0/0x184
rest_init from arch_post_acpi_subsys_init+0x0/0x8

Reported-by: Tim van der Staaij <Tim.vanderstaaij@zigngroup.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Link: https://lore.kernel.org/r/20230928064320.711603-1-s.hauer@pengutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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Merge tag 'v6.6-rc4' into perf/core, to pick up fixes

Signed-off-by: Ingo Molnar <mingo@kernel.org>

Merge tag 'v6.6-rc2' into locking/core, to pick up fixes

Signed-off-by: Ingo Molnar <mingo@kernel.org>

serial: imx: Use port lock wrappers

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 in

serial: imx: Use port lock wrappers

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/20230914183831.587273-30-john.ogness@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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serial: imx: Simplify compatibility handling

Three of the four entries of imx_uart_devdata[] use .uts_reg =
IMX21_UTS. The difference in the .devtype member isn't relevant, the
only thing that matte

serial: imx: Simplify compatibility handling

Three of the four entries of imx_uart_devdata[] use .uts_reg =
IMX21_UTS. The difference in the .devtype member isn't relevant, the
only thing that matters is if is equal to IMX1_UART.

So use an entry with .devtype = IMX21_UART on all platforms but i.MX1.
There is no need to have the dev types in an array, so split them up in
two separate variables.

The fsl,imx53-uart devinfo can go away because in the binding and also
the dts files all fsl,imx53-uart devices also are compatible to
fsl,imx21-uart. That's not the case for fsl,imx6q-uart (which is a bit
strange IMHO), so the fsl,imx6q-uart must stay around.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20230911085451.628798-1-u.kleine-koenig@pengutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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Merge drm/drm-next into drm-intel-next

Sync to v6.6-rc1.

Signed-off-by: Jani Nikula <jani.nikula@intel.com>

Merge drm/drm-fixes into drm-misc-fixes

Forwarding to v6.6-rc1.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>

Merge tag 'v6.5' into next

Sync up with mainline to bring in updates to the shared infrastructure.

Merge tag 'tty-6.6-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 6.6-rc1.

Merge tag 'tty-6.6-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 6.6-rc1.

Lots of cleanups in here this cycle, and some driver updates. Short
summary is:

- Jiri's continued work to make the tty code and apis be a bit more
sane with regards to modern kernel coding style and types

- cpm_uart driver updates

- n_gsm updates and fixes

- meson driver updates

- sc16is7xx driver updates

- 8250 driver updates for different hardware types

- qcom-geni driver fixes

- tegra serial driver change

- stm32 driver updates

- synclink_gt driver cleanups

- tty structure size reduction

All of these have been in linux-next this week with no reported
issues. The last bit of cleanups from Jiri and the tty structure size
reduction came in last week, a bit late but as they were just style
changes and size reductions, I figured they should get into this merge
cycle so that others can work on top of them with no merge conflicts"

* tag 'tty-6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (199 commits)
tty: shrink the size of struct tty_struct by 40 bytes
tty: n_tty: deduplicate copy code in n_tty_receive_buf_real_raw()
tty: n_tty: extract ECHO_OP processing to a separate function
tty: n_tty: unify counts to size_t
tty: n_tty: use u8 for chars and flags
tty: n_tty: simplify chars_in_buffer()
tty: n_tty: remove unsigned char casts from character constants
tty: n_tty: move newline handling to a separate function
tty: n_tty: move canon handling to a separate function
tty: n_tty: use MASK() for masking out size bits
tty: n_tty: make n_tty_data::num_overrun unsigned
tty: n_tty: use time_is_before_jiffies() in n_tty_receive_overrun()
tty: n_tty: use 'num' for writes' counts
tty: n_tty: use output character directly
tty: n_tty: make flow of n_tty_receive_buf_common() a bool
Revert "tty: serial: meson: Add a earlycon for the T7 SoC"
Documentation: devices.txt: Fix minors for ttyCPM*
Documentation: devices.txt: Remove ttySIOC*
Documentation: devices.txt: Remove ttyIOC*
serial: 8250_bcm7271: improve bcm7271 8250 port
...

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Merge branch 'next' into for-linus

Prepare input updates for 6.6 merge window.

Merge drm/drm-next into drm-intel-next

Catching-up with drm-next and drm-intel-gt-next.
It will unblock a code refactor around the platform
definitions (names vs acronyms).

Signed-off-by: Rodrigo V

Merge drm/drm-next into drm-intel-next

Catching-up with drm-next and drm-intel-gt-next.
It will unblock a code refactor around the platform
definitions (names vs acronyms).

Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

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Merge drm/drm-next into drm-intel-gt-next

Need to pull in b3e4aae612ec ("drm/i915/hdcp: Modify hdcp_gsc_message msg sending mechanism") as
a dependency for https://patchwork.freedesktop.org/series/1

Merge drm/drm-next into drm-intel-gt-next

Need to pull in b3e4aae612ec ("drm/i915/hdcp: Modify hdcp_gsc_message msg sending mechanism") as
a dependency for https://patchwork.freedesktop.org/series/121735/

Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>

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