linux-stable.git/drivers/tty/serial, branch v5.4.217

serial: tegra-tcu: Use uart_xmit_advance(), fixes icount.tx accounting

2022-09-28T09:04:08+00:00

commit 1d10cd4da593bc0196a239dcc54dac24b6b0a74e upstream.

Tx'ing does not correctly account Tx'ed characters into icount.tx.
Using uart_xmit_advance() fixes the problem.

Fixes: 2d908b38d409 ("serial: Add Tegra Combined UART driver")
Cc:  # serial: Create uart_xmit_advance()
Reviewed-by: Andy Shevchenko 
Signed-off-by: Ilpo Järvinen 
Link: https://lore.kernel.org/r/20220901143934.8850-4-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman

serial: tegra: Use uart_xmit_advance(), fixes icount.tx accounting

2022-09-28T09:04:08+00:00

commit 754f68044c7dd6c52534ba3e0f664830285c4b15 upstream.

DMA complete & stop paths did not correctly account Tx'ed characters
into icount.tx. Using uart_xmit_advance() fixes the problem.

Fixes: e9ea096dd225 ("serial: tegra: add serial driver")
Cc:  # serial: Create uart_xmit_advance()
Reviewed-by: Andy Shevchenko 
Signed-off-by: Ilpo Järvinen 
Link: https://lore.kernel.org/r/20220901143934.8850-3-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman

tty: serial: atmel: Preserve previous USART mode if RS485 disabled

2022-09-28T09:04:02+00:00

[ Upstream commit 692a8ebcfc24f4a5bea0eb2967e450f584193da6 ]

Whenever the atmel_rs485_config() driver method would be called,
the USART mode is reset to normal mode before even checking if
RS485 flag is set, thus resulting in losing the previous USART
mode in the case where the checking fails.

Some tools, such as `linux-serial-test`, lead to the driver calling
this method when doing the setup of the serial port: after setting the
port mode (Hardware Flow Control, Normal Mode, RS485 Mode, etc.),
`linux-serial-test` tries to enable/disable RS485 depending on
the commandline arguments that were passed.

Example of how this issue could reveal itself:
When doing a serial communication with Hardware Flow Control through
`linux-serial-test`, the tool would lead to the driver roughly doing
the following:
- set the corresponding bit to 1 (ATMEL_US_USMODE_HWHS bit in the
ATMEL_US_MR register) through the atmel_set_termios() to enable
Hardware Flow Control
- disable RS485 through the atmel_config_rs485() method
Thus, when the latter is called, the mode will be reset and the
previously set bit is unset, leaving USART in normal mode instead of
the expected Hardware Flow Control mode.

This fix ensures that this reset is only done if the checking for
RS485 succeeds and that the previous mode is preserved otherwise.

Fixes: e8faff7330a35 ("ARM: 6092/1: atmel_serial: support for RS485 communications")
Cc: stable 
Reviewed-by: Ilpo Järvinen 
Signed-off-by: Sergiu Moga 
Link: https://lore.kernel.org/r/20220824142902.502596-1-sergiu.moga@microchip.com
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Sasha Levin

serial: atmel: remove redundant assignment in rs485_config

2022-09-28T09:04:02+00:00

[ Upstream commit 60efd0513916f195dd85bfbf21653f74f9ab019c ]

In uart_set_rs485_config() the serial core already assigns the passed
serial_rs485 struct to the uart port.

So remove the assignment from the drivers rs485_config() function to avoid
redundancy.

Reviewed-by: Claudiu Beznea 
Acked-by: Richard Genoud 
Signed-off-by: Lino Sanfilippo 
Link: https://lore.kernel.org/r/20220410104642.32195-10-LinoSanfilippo@gmx.de
Signed-off-by: Greg Kroah-Hartman 
Stable-dep-of: 692a8ebcfc24 ("tty: serial: atmel: Preserve previous USART mode if RS485 disabled")
Signed-off-by: Sasha Levin

tty/serial: atmel: RS485 & ISO7816: wait for TXRDY before sending data

2022-09-28T09:04:02+00:00

[ Upstream commit 477b8383100023ea0769979cff67e9be3a720397 ]

At this moment, TXEMPTY is checked before sending data on RS485 and ISO7816
modes. However, TXEMPTY is risen when FIFO (if used) or the Transmit Shift
Register are empty, even though TXRDY might be up and controller is able to
receive data. Since the controller sends data only when TXEMPTY is ready,
on RS485, when DMA is not used, the RTS pin is driven low after each byte.
With this patch, the characters will be transmitted when TXRDY is up and
so, RTS pin will remain high between bytes.
The performance improvement on RS485 is about 8% with a baudrate of 300.

Signed-off-by: Codrin Ciubotariu 
Acked-by: Richard Genoud 
Link: https://lore.kernel.org/r/20200107111656.26308-1-codrin.ciubotariu@microchip.com
Signed-off-by: Greg Kroah-Hartman 
Stable-dep-of: 692a8ebcfc24 ("tty: serial: atmel: Preserve previous USART mode if RS485 disabled")
Signed-off-by: Sasha Levin

tty: serial: lpuart: disable flow control while waiting for the transmit engine to complete

2022-09-15T10:04:51+00:00

commit d5a2e0834364377a5d5a2fff1890a0b3f0bafd1f upstream.

When the user initializes the uart port, and waits for the transmit
engine to complete in lpuart32_set_termios(), if the UART TX fifo has
dirty data and the UARTMODIR enable the flow control, the TX fifo may
never be empty. So here we should disable the flow control first to make
sure the transmit engin can complete.

Fixes: 380c966c093e ("tty: serial: fsl_lpuart: add 32-bit register interface support")
Cc: stable 
Signed-off-by: Sherry Sun 
Link: https://lore.kernel.org/r/20220821101527.10066-1-sherry.sun@nxp.com
Signed-off-by: Greg Kroah-Hartman

serial: fsl_lpuart: RS485 RTS polariy is inverse

2022-09-15T10:04:50+00:00

commit 846651eca073e2e02e37490a4a52752415d84781 upstream.

The setting of RS485 RTS polarity is inverse in the current driver.

When the property of 'rs485-rts-active-low' is enabled in the dts node,
the RTS signal should be LOW during sending. Otherwise, if there is no
such a property, the RTS should be HIGH during sending.

Fixes: 03895cf41d18 ("tty: serial: fsl_lpuart: Add support for RS-485")
Cc: stable 
Signed-off-by: Nicolas Diaz 
Signed-off-by: Shenwei Wang 
Link: https://lore.kernel.org/r/20220805144529.604856-1-shenwei.wang@nxp.com
Signed-off-by: Greg Kroah-Hartman

tty: serial: Fix refcount leak bug in ucc_uart.c

2022-08-25T09:18:36+00:00

[ Upstream commit d24d7bb2cd947676f9b71fb944d045e09b8b282f ]

In soc_info(), of_find_node_by_type() will return a node pointer
with refcount incremented. We should use of_node_put() when it is
not used anymore.

Acked-by: Timur Tabi 
Signed-off-by: Liang He 
Link: https://lore.kernel.org/r/20220618060850.4058525-1-windhl@126.com
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Sasha Levin

serial: 8250_dw: Store LSR into lsr_saved_flags in dw8250_tx_wait_empty()

2022-08-25T09:18:01+00:00

[ Upstream commit af14f3007e2dca0d112f10f6717ba43093f74e81 ]

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: 914eaf935ec7 ("serial: 8250_dw: Allow TX FIFO to drain before writing to UART_LCR")
Reviewed-by: Andy Shevchenko 
Signed-off-by: Ilpo Järvinen 
Link: https://lore.kernel.org/r/20220608095431.18376-7-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Sasha Levin

serial: mvebu-uart: uart2 error bits clearing

2022-08-25T09:17:24+00:00

commit a7209541239e5dd44d981289e5f9059222d40fd1 upstream.

For mvebu uart2, error bits are not cleared on buffer read.
This causes interrupt loop and system hang.

Cc: stable@vger.kernel.org
Reviewed-by: Yi Guo 
Reviewed-by: Nadav Haklai 
Signed-off-by: Narendra Hadke 
Signed-off-by: Pali Rohár 
Link: https://lore.kernel.org/r/20220726091221.12358-1-pali@kernel.org
Signed-off-by: Greg Kroah-Hartman