linux-stable.git/drivers/tty/serial, branch v6.14.2 Linux kernel stable tree tty: serial: lpuart: only disable CTS instead of overwriting the whole UARTMODIR register 2025-04-10T12:44:43+00:00 Sherry Sun sherry.sun@nxp.com 2025-03-07T06:54:46+00:00 80a72e6380fd2402475e7f747ce4952aac3e17be [ Upstream commit e98ab45ec5182605d2e00114cba3bbf46b0ea27f ] No need to overwrite the whole UARTMODIR register before waiting the transmit engine complete, actually our target here is only to disable CTS flow control to avoid the dirty data in TX FIFO may block the transmit engine complete. Also delete the following duplicate CTS disable configuration. Fixes: d5a2e0834364 ("tty: serial: lpuart: disable flow control while waiting for the transmit engine to complete") Cc: stable <stable@kernel.org> Signed-off-by: Sherry Sun <sherry.sun@nxp.com> Link: https://lore.kernel.org/r/20250307065446.1122482-1-sherry.sun@nxp.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit e98ab45ec5182605d2e00114cba3bbf46b0ea27f ]

No need to overwrite the whole UARTMODIR register before waiting the
transmit engine complete, actually our target here is only to disable
CTS flow control to avoid the dirty data in TX FIFO may block the
transmit engine complete.
Also delete the following duplicate CTS disable configuration.

Fixes: d5a2e0834364 ("tty: serial: lpuart: disable flow control while waiting for the transmit engine to complete")
Cc: stable <stable@kernel.org>
Signed-off-by: Sherry Sun <sherry.sun@nxp.com>
Link: https://lore.kernel.org/r/20250307065446.1122482-1-sherry.sun@nxp.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
tty: serial: fsl_lpuart: Fix unused variable 'sport' build warning 2025-04-10T12:44:43+00:00 Sherry Sun sherry.sun@nxp.com 2025-03-24T02:10:51+00:00 fa00a5fccd0ce42a444b69119601737ef36e62df commit 9f8fe348ac9544f6855f82565e754bf085d81f88 upstream. Remove the unused variable 'sport' to avoid the kernel build warning. Fixes: 3cc16ae096f1 ("tty: serial: fsl_lpuart: use port struct directly to simply code") Reported-by: kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202503210614.2qGlnbIq-lkp@intel.com/ Signed-off-by: Sherry Sun <sherry.sun@nxp.com> Link: https://lore.kernel.org/r/20250324021051.162676-1-sherry.sun@nxp.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 9f8fe348ac9544f6855f82565e754bf085d81f88 upstream.

Remove the unused variable 'sport' to avoid the kernel build warning.

Fixes: 3cc16ae096f1 ("tty: serial: fsl_lpuart: use port struct directly to simply code")
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202503210614.2qGlnbIq-lkp@intel.com/
Signed-off-by: Sherry Sun <sherry.sun@nxp.com>
Link: https://lore.kernel.org/r/20250324021051.162676-1-sherry.sun@nxp.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
tty: serial: fsl_lpuart: use port struct directly to simply code 2025-04-10T12:44:43+00:00 Sherry Sun sherry.sun@nxp.com 2025-03-12T02:39:03+00:00 2526110174c7b5e33f3ebac3e1540443b0715dbe commit 3cc16ae096f164ae0c6b98416c25a01db5f3a529 upstream. Most lpuart functions have the parameter struct uart_port *port, but still use the &sport->port to get the uart_port instead of use it directly, let's simply the code logic, directly use this struct instead of covert it from struct sport. Signed-off-by: Sherry Sun <sherry.sun@nxp.com> Link: https://lore.kernel.org/r/20250312023904.1343351-3-sherry.sun@nxp.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 3cc16ae096f164ae0c6b98416c25a01db5f3a529 upstream.

Most lpuart functions have the parameter struct uart_port *port, but
still use the &sport->port to get the uart_port instead of use it
directly, let's simply the code logic, directly use this struct instead
of covert it from struct sport.

Signed-off-by: Sherry Sun <sherry.sun@nxp.com>
Link: https://lore.kernel.org/r/20250312023904.1343351-3-sherry.sun@nxp.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
tty: serial: fsl_lpuart: Use u32 and u8 for register variables 2025-04-10T12:44:43+00:00 Sherry Sun sherry.sun@nxp.com 2025-03-12T02:39:02+00:00 7b0b0c70de2f68c75a5da2c76c2a2856cd9847df [ Upstream commit b6a8f6ab2c53e5ea3c7f2a3978db378a89bb7595 ] Use u32 and u8 rather than unsigned long or unsigned char for register variables for clarity and consistency. Signed-off-by: Sherry Sun <sherry.sun@nxp.com> Link: https://lore.kernel.org/r/20250312023904.1343351-2-sherry.sun@nxp.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Stable-dep-of: e98ab45ec518 ("tty: serial: lpuart: only disable CTS instead of overwriting the whole UARTMODIR register") Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit b6a8f6ab2c53e5ea3c7f2a3978db378a89bb7595 ]

Use u32 and u8 rather than unsigned long or unsigned char for register
variables for clarity and consistency.

Signed-off-by: Sherry Sun <sherry.sun@nxp.com>
Link: https://lore.kernel.org/r/20250312023904.1343351-2-sherry.sun@nxp.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Stable-dep-of: e98ab45ec518 ("tty: serial: lpuart: only disable CTS instead of overwriting the whole UARTMODIR register")
Signed-off-by: Sasha Levin <sashal@kernel.org>
serial: 8250_dma: terminate correct DMA in tx_dma_flush() 2025-04-07T08:11:12+00:00 John Keeping jkeeping@inmusicbrands.com 2025-02-24T12:18:30+00:00 6e1eee76c8096edb03e9a6a4a35056ce29eb4379 commit a26503092c75abba70a0be2aa01145ecf90c2a22 upstream. When flushing transmit side DMA, it is the transmit channel that should be terminated, not the receive channel. Fixes: 9e512eaaf8f40 ("serial: 8250: Fix fifo underflow on flush") Cc: stable <stable@kernel.org> Reported-by: Wentao Guan <guanwentao@uniontech.com> Signed-off-by: John Keeping <jkeeping@inmusicbrands.com> Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20250224121831.1429323-1-jkeeping@inmusicbrands.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit a26503092c75abba70a0be2aa01145ecf90c2a22 upstream.

When flushing transmit side DMA, it is the transmit channel that should
be terminated, not the receive channel.

Fixes: 9e512eaaf8f40 ("serial: 8250: Fix fifo underflow on flush")
Cc: stable <stable@kernel.org>
Reported-by: Wentao Guan <guanwentao@uniontech.com>
Signed-off-by: John Keeping <jkeeping@inmusicbrands.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20250224121831.1429323-1-jkeeping@inmusicbrands.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
serial: stm32: do not deassert RS485 RTS GPIO prematurely 2025-04-07T08:11:12+00:00 Cheick Traore cheick.traore@foss.st.com 2025-03-20T15:25:40+00:00 cf1eda0b9f1af2e93c07d7c52b79101d9d21526c commit 2790ce23951f0c497810c44ad60a126a59c8d84c upstream. If stm32_usart_start_tx is called with an empty xmit buffer, RTS GPIO could be deasserted prematurely, as bytes in TX FIFO are still transmitting. So this patch remove rts disable when xmit buffer is empty. Fixes: d7c76716169d ("serial: stm32: Use TC interrupt to deassert GPIO RTS in RS485 mode") Cc: stable <stable@kernel.org> Signed-off-by: Cheick Traore <cheick.traore@foss.st.com> Link: https://lore.kernel.org/r/20250320152540.709091-1-cheick.traore@foss.st.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 2790ce23951f0c497810c44ad60a126a59c8d84c upstream.

If stm32_usart_start_tx is called with an empty xmit buffer, RTS GPIO
could be deasserted prematurely, as bytes in TX FIFO are still
transmitting.
So this patch remove rts disable when xmit buffer is empty.

Fixes: d7c76716169d ("serial: stm32: Use TC interrupt to deassert GPIO RTS in RS485 mode")
Cc: stable <stable@kernel.org>
Signed-off-by: Cheick Traore <cheick.traore@foss.st.com>
Link: https://lore.kernel.org/r/20250320152540.709091-1-cheick.traore@foss.st.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
tty: serial: fsl_lpuart: disable transmitter before changing RS485 related registers 2025-04-07T08:11:11+00:00 Sherry Sun sherry.sun@nxp.com 2025-03-12T02:25:03+00:00 126049ffdc0d50657e3d8a804d6af700e9922531 commit f5cb528d6441eb860250a2f085773aac4f44085e upstream. According to the LPUART reference manual, TXRTSE and TXRTSPOL of MODIR register only can be changed when the transmitter is disabled. So disable the transmitter before changing RS485 related registers and re-enable it after the change is done. Fixes: 67b01837861c ("tty: serial: lpuart: Add RS485 support for 32-bit uart flavour") Cc: stable <stable@kernel.org> Signed-off-by: Sherry Sun <sherry.sun@nxp.com> Reviewed-by: Frank Li <Frank.Li@nxp.com> Link: https://lore.kernel.org/r/20250312022503.1342990-1-sherry.sun@nxp.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit f5cb528d6441eb860250a2f085773aac4f44085e upstream.

According to the LPUART reference manual, TXRTSE and TXRTSPOL of MODIR
register only can be changed when the transmitter is disabled.
So disable the transmitter before changing RS485 related registers and
re-enable it after the change is done.

Fixes: 67b01837861c ("tty: serial: lpuart: Add RS485 support for 32-bit uart flavour")
Cc: stable <stable@kernel.org>
Signed-off-by: Sherry Sun <sherry.sun@nxp.com>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Link: https://lore.kernel.org/r/20250312022503.1342990-1-sherry.sun@nxp.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
tty: serial: 8250: Add Brainboxes XC devices 2025-04-07T08:11:11+00:00 Cameron Williams cang1@live.co.uk 2025-03-10T22:27:10+00:00 5247eeaafa03e90a883dabe06760e6ca09f56901 commit 5c7e2896481a177bbda41d7850f05a9f5a8aee2b upstream. These ExpressCard devices use the OxPCIE chip and can be used with this driver. Signed-off-by: Cameron Williams <cang1@live.co.uk> Cc: stable <stable@kernel.org> Link: https://lore.kernel.org/r/DB7PR02MB3802907A9360F27F6CD67AAFC4D62@DB7PR02MB3802.eurprd02.prod.outlook.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 5c7e2896481a177bbda41d7850f05a9f5a8aee2b upstream.

These ExpressCard devices use the OxPCIE chip and can be used with
this driver.

Signed-off-by: Cameron Williams <cang1@live.co.uk>
Cc: stable <stable@kernel.org>
Link: https://lore.kernel.org/r/DB7PR02MB3802907A9360F27F6CD67AAFC4D62@DB7PR02MB3802.eurprd02.prod.outlook.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
tty: serial: 8250: Add some more device IDs 2025-04-07T08:11:11+00:00 Cameron Williams cang1@live.co.uk 2025-02-23T22:07:38+00:00 529be5444816b79e4b56e7877b641b476f80d77b commit be6a23650908e2f827f2e7839a3fbae41ccb5b63 upstream. These card IDs got missed the first time around. Cc: stable <stable@kernel.org> Signed-off-by: Cameron Williams <cang1@live.co.uk> Link: https://lore.kernel.org/r/DB7PR02MB380295BCC879CCF91315AC38C4C12@DB7PR02MB3802.eurprd02.prod.outlook.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit be6a23650908e2f827f2e7839a3fbae41ccb5b63 upstream.

These card IDs got missed the first time around.

Cc: stable <stable@kernel.org>
Signed-off-by: Cameron Williams <cang1@live.co.uk>
Link: https://lore.kernel.org/r/DB7PR02MB380295BCC879CCF91315AC38C4C12@DB7PR02MB3802.eurprd02.prod.outlook.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
serial: 8250: Fix fifo underflow on flush 2025-02-14T08:50:55+00:00 John Keeping jkeeping@inmusicbrands.com 2025-02-08T12:41:44+00:00 9e512eaaf8f4008c44ede3dfc0fbc9d9c5118583 When flushing the serial port's buffer, uart_flush_buffer() calls kfifo_reset() but if there is an outstanding DMA transfer then the completion function will consume data from the kfifo via uart_xmit_advance(), underflowing and leading to ongoing DMA as the driver tries to transmit another 2^32 bytes. This is readily reproduced with serial-generic and amidi sending even short messages as closing the device on exit will wait for the fifo to drain and in the underflow case amidi hangs for 30 seconds on exit in tty_wait_until_sent(). A trace of that gives: kworker/1:1-84 [001] 51.769423: bprint: serial8250_tx_dma: tx_size=3 fifo_len=3 amidi-763 [001] 51.769460: bprint: uart_flush_buffer: resetting fifo irq/21-fe530000-76 [000] 51.769474: bprint: __dma_tx_complete: tx_size=3 irq/21-fe530000-76 [000] 51.769479: bprint: serial8250_tx_dma: tx_size=4096 fifo_len=4294967293 irq/21-fe530000-76 [000] 51.781295: bprint: __dma_tx_complete: tx_size=4096 irq/21-fe530000-76 [000] 51.781301: bprint: serial8250_tx_dma: tx_size=4096 fifo_len=4294963197 irq/21-fe530000-76 [000] 51.793131: bprint: __dma_tx_complete: tx_size=4096 irq/21-fe530000-76 [000] 51.793135: bprint: serial8250_tx_dma: tx_size=4096 fifo_len=4294959101 irq/21-fe530000-76 [000] 51.804949: bprint: __dma_tx_complete: tx_size=4096 Since the port lock is held in when the kfifo is reset in uart_flush_buffer() and in __dma_tx_complete(), adding a flush_buffer hook to adjust the outstanding DMA byte count is sufficient to avoid the kfifo underflow. Fixes: 9ee4b83e51f74 ("serial: 8250: Add support for dmaengine") Cc: stable <stable@kernel.org> Signed-off-by: John Keeping <jkeeping@inmusicbrands.com> Link: https://lore.kernel.org/r/20250208124148.1189191-1-jkeeping@inmusicbrands.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
When flushing the serial port's buffer, uart_flush_buffer() calls
kfifo_reset() but if there is an outstanding DMA transfer then the
completion function will consume data from the kfifo via
uart_xmit_advance(), underflowing and leading to ongoing DMA as the
driver tries to transmit another 2^32 bytes.

This is readily reproduced with serial-generic and amidi sending even
short messages as closing the device on exit will wait for the fifo to
drain and in the underflow case amidi hangs for 30 seconds on exit in
tty_wait_until_sent().  A trace of that gives:

     kworker/1:1-84    [001]    51.769423: bprint:               serial8250_tx_dma: tx_size=3 fifo_len=3
           amidi-763   [001]    51.769460: bprint:               uart_flush_buffer: resetting fifo
 irq/21-fe530000-76    [000]    51.769474: bprint:               __dma_tx_complete: tx_size=3
 irq/21-fe530000-76    [000]    51.769479: bprint:               serial8250_tx_dma: tx_size=4096 fifo_len=4294967293
 irq/21-fe530000-76    [000]    51.781295: bprint:               __dma_tx_complete: tx_size=4096
 irq/21-fe530000-76    [000]    51.781301: bprint:               serial8250_tx_dma: tx_size=4096 fifo_len=4294963197
 irq/21-fe530000-76    [000]    51.793131: bprint:               __dma_tx_complete: tx_size=4096
 irq/21-fe530000-76    [000]    51.793135: bprint:               serial8250_tx_dma: tx_size=4096 fifo_len=4294959101
 irq/21-fe530000-76    [000]    51.804949: bprint:               __dma_tx_complete: tx_size=4096

Since the port lock is held in when the kfifo is reset in
uart_flush_buffer() and in __dma_tx_complete(), adding a flush_buffer
hook to adjust the outstanding DMA byte count is sufficient to avoid the
kfifo underflow.

Fixes: 9ee4b83e51f74 ("serial: 8250: Add support for dmaengine")
Cc: stable <stable@kernel.org>
Signed-off-by: John Keeping <jkeeping@inmusicbrands.com>
Link: https://lore.kernel.org/r/20250208124148.1189191-1-jkeeping@inmusicbrands.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>