linux-stable.git/drivers/tty, branch v5.4.255

serial: 8250: Fix oops for port->pm on uart_change_pm()

2023-08-30T14:27:18+00:00

[ Upstream commit dfe2aeb226fd5e19b0ee795f4f6ed8bc494c1534 ]

Unloading a hardware specific 8250 driver can produce error "Unable to
handle kernel paging request at virtual address" about ten seconds after
unloading the driver. This happens on uart_hangup() calling
uart_change_pm().

Turns out commit 04e82793f068 ("serial: 8250: Reinit port->pm on port
specific driver unbind") was only a partial fix. If the hardware specific
driver has initialized port->pm function, we need to clear port->pm too.
Just reinitializing port->ops does not do this. Otherwise serial8250_pm()
will call port->pm() instead of serial8250_do_pm().

Fixes: 04e82793f068 ("serial: 8250: Reinit port->pm on port specific driver unbind")
Signed-off-by: Tony Lindgren 
Link: https://lore.kernel.org/r/20230804131553.52927-1-tony@atomide.com
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Sasha Levin

tty: serial: fsl_lpuart: Clear the error flags by writing 1 for lpuart32 platforms

2023-08-30T14:27:15+00:00

commit 282069845af388b08d622ad192b831dcd0549c62 upstream.

Do not read the data register to clear the error flags for lpuart32
platforms, the additional read may cause the receive FIFO underflow
since the DMA has already read the data register.
Actually all lpuart32 platforms support write 1 to clear those error
bits, let's use this method to better clear the error flags.

Fixes: 42b68768e51b ("serial: fsl_lpuart: DMA support for 32-bit variant")
Cc: stable 
Signed-off-by: Sherry Sun 
Link: https://lore.kernel.org/r/20230801022304.24251-1-sherry.sun@nxp.com
Signed-off-by: Greg Kroah-Hartman

serial: sifive: Fix sifive_serial_console_setup() section

2023-08-11T09:53:50+00:00

commit 9b8fef6345d5487137d4193bb0a0eae2203c284e upstream.

This function is called indirectly from the platform driver probe
function. Even if the driver is built in, it may be probed after
free_initmem() due to deferral or unbinding/binding via sysfs.
Thus the function cannot be marked as __init.

Fixes: 45c054d0815b ("tty: serial: add driver for the SiFive UART")
Cc: stable 
Signed-off-by: Samuel Holland 
Link: https://lore.kernel.org/r/20230624060159.3401369-1-samuel.holland@sifive.com
Signed-off-by: Greg Kroah-Hartman

serial: 8250_dw: Preserve original value of DLF register

2023-08-11T09:53:50+00:00

commit 748c5ea8b8796ae8ee80b8d3a3d940570b588d59 upstream.

Preserve the original value of the Divisor Latch Fraction (DLF) register.
When the DLF register is modified without preservation, it can disrupt
the baudrate settings established by firmware or bootloader, leading to
data corruption and the generation of unreadable or distorted characters.

Fixes: 701c5e73b296 ("serial: 8250_dw: add fractional divisor support")
Cc: stable 
Signed-off-by: Ruihong Luo 
Link: https://lore.kernel.org/stable/20230713004235.35904-1-colorsu1922%40gmail.com
Reviewed-by: Ilpo Järvinen 
Reviewed-by: Andy Shevchenko 
Link: https://lore.kernel.org/r/20230713004235.35904-1-colorsu1922@gmail.com
Signed-off-by: Greg Kroah-Hartman

tty: serial: samsung_tty: Fix a memory leak in s3c24xx_serial_getclk() when iterating clk

2023-07-27T06:37:38+00:00

commit 832e231cff476102e8204a9e7bddfe5c6154a375 upstream.

When the best clk is searched, we iterate over all possible clk.

If we find a better match, the previous one, if any, needs to be freed.
If a better match has already been found, we still need to free the new
one, otherwise it leaks.

Cc:  # v3.3+
Reviewed-by: Krzysztof Kozlowski 
Reviewed-by: Andi Shyti 
Fixes: 5f5a7a5578c5 ("serial: samsung: switch to clkdev based clock lookup")
Signed-off-by: Christophe JAILLET 
Reviewed-by: Jiri Slaby 
Message-ID: 
Signed-off-by: Greg Kroah-Hartman

tty: serial: samsung_tty: Fix a memory leak in s3c24xx_serial_getclk() in case of error

2023-07-27T06:37:38+00:00

commit a9c09546e903f1068acfa38e1ee18bded7114b37 upstream.

If clk_get_rate() fails, the clk that has just been allocated needs to be
freed.

Cc:  # v3.3+
Reviewed-by: Krzysztof Kozlowski 
Reviewed-by: Andi Shyti 
Fixes: 5f5a7a5578c5 ("serial: samsung: switch to clkdev based clock lookup")
Signed-off-by: Christophe JAILLET 
Reviewed-by: Jiri Slaby 
Message-ID: 
Signed-off-by: Greg Kroah-Hartman

Revert "8250: add support for ASIX devices with a FIFO bug"

2023-07-27T06:37:38+00:00

commit a82d62f708545d22859584e0e0620da8e3759bbc upstream.

This reverts commit eb26dfe8aa7eeb5a5aa0b7574550125f8aa4c3b3.

Commit eb26dfe8aa7e ("8250: add support for ASIX devices with a FIFO
bug") merged on Jul 13, 2012 adds a quirk for PCI_VENDOR_ID_ASIX
(0x9710). But that ID is the same as PCI_VENDOR_ID_NETMOS defined in
1f8b061050c7 ("[PATCH] Netmos parallel/serial/combo support") merged
on Mar 28, 2005. In pci_serial_quirks array, the NetMos entry always
takes precedence over the ASIX entry even since it was initially
merged, code in that commit is always unreachable.

In my tests, adding the FIFO workaround to pci_netmos_init() makes no
difference, and the vendor driver also does not have such workaround.
Given that the code was never used for over a decade, it's safe to
revert it.

Also, the real PCI_VENDOR_ID_ASIX should be 0x125b, which is used on
their newer AX99100 PCIe serial controllers released on 2016. The FIFO
workaround should not be intended for these newer controllers, and it
was never implemented in vendor driver.

Fixes: eb26dfe8aa7e ("8250: add support for ASIX devices with a FIFO bug")
Cc: stable 
Signed-off-by: Jiaqing Zhao 
Reviewed-by: Andy Shevchenko 
Link: https://lore.kernel.org/r/20230619155743.827859-1-jiaqing.zhao@linux.intel.com
Signed-off-by: Greg Kroah-Hartman

serial: atmel: don't enable IRQs prematurely

2023-07-27T06:37:37+00:00

commit 27a826837ec9a3e94cc44bd9328b8289b0fcecd7 upstream.

The atmel_complete_tx_dma() function disables IRQs at the start
of the function by calling spin_lock_irqsave(&port->lock, flags);
There is no need to disable them a second time using the
spin_lock_irq() function and, in fact, doing so is a bug because
it will enable IRQs prematurely when we call spin_unlock_irq().

Just use spin_lock/unlock() instead without disabling or enabling
IRQs.

Fixes: 08f738be88bb ("serial: at91: add tx dma support")
Signed-off-by: Dan Carpenter 
Reviewed-by: Jiri Slaby 
Acked-by: Richard Genoud 
Link: https://lore.kernel.org/r/cb7c39a9-c004-4673-92e1-be4e34b85368@moroto.mountain
Cc: stable 
Signed-off-by: Greg Kroah-Hartman

tty: serial: fsl_lpuart: add earlycon for imx8ulp platform

2023-07-27T06:37:28+00:00

commit e0edfdc15863ec80a1d9ac6e174dbccc00206dd0 upstream.

Add earlycon support for imx8ulp platform.

Signed-off-by: Sherry Sun 
Cc: stable 
Link: https://lore.kernel.org/r/20230619080613.16522-1-sherry.sun@nxp.com
Signed-off-by: Greg Kroah-Hartman

serial: 8250_omap: Use force_suspend and resume for system suspend

2023-07-27T06:37:21+00:00

[ Upstream commit 20a41a62618df85f3a2981008edec5cadd785e0a ]

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 
Tested-by: Dhruva Gole 
Message-ID: <20230614045922.4798-1-tony@atomide.com>
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Sasha Levin