linux-stable.git/drivers/tty, branch v5.4.293

serial: sifive: lock port in startup()/shutdown() callbacks

2025-05-02T05:39:26+00:00

commit e1ca3ff28ab1e2c1e70713ef3fa7943c725742c3 upstream.

startup()/shutdown() callbacks access SIFIVE_SERIAL_IE_OFFS.
The register is also accessed from write() callback.

If console were printing and startup()/shutdown() callback
gets called, its access to the register could be overwritten.

Add port->lock to startup()/shutdown() callbacks to make sure
their access to SIFIVE_SERIAL_IE_OFFS is synchronized against
write() callback.

Fixes: 45c054d0815b ("tty: serial: add driver for the SiFive UART")
Signed-off-by: Ryo Takakura 
Reviewed-by: Petr Mladek 
Cc: stable@vger.kernel.org
Reviewed-by: John Ogness 
Rule: add
Link: https://lore.kernel.org/stable/20250330003522.386632-1-ryotkkr98%40gmail.com
Link: https://lore.kernel.org/r/20250412001847.183221-1-ryotkkr98@gmail.com
Signed-off-by: Greg Kroah-Hartman

serial: 8250_dma: terminate correct DMA in tx_dma_flush()

2025-04-10T12:29:39+00:00

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 
Reported-by: Wentao Guan 
Signed-off-by: John Keeping 
Reviewed-by: Ilpo Järvinen 
Link: https://lore.kernel.org/r/20250224121831.1429323-1-jkeeping@inmusicbrands.com
Signed-off-by: Greg Kroah-Hartman

tty: serial: 8250: Add some more device IDs

2025-04-10T12:29:39+00:00

commit be6a23650908e2f827f2e7839a3fbae41ccb5b63 upstream.

These card IDs got missed the first time around.

Cc: stable 
Signed-off-by: Cameron Williams 
Link: https://lore.kernel.org/r/DB7PR02MB380295BCC879CCF91315AC38C4C12@DB7PR02MB3802.eurprd02.prod.outlook.com
Signed-off-by: Greg Kroah-Hartman

serial: 8250_pci: add support for ASIX AX99100

2025-03-13T11:43:19+00:00

commit 0b32216557ce3b2a468d1282d99b428bf72ff532 upstream.

Each of the 4 PCI functions on ASIX AX99100 PCIe to Multi I/O
Controller can be configured as a single-port serial port controller.
The subvendor id is 0x1000 when configured as serial port and MSI
interrupts are supported.

Signed-off-by: Jiaqing Zhao 
Reviewed-by: Andy Shevchenko 
Link: https://lore.kernel.org/r/20230724083933.3173513-4-jiaqing.zhao@linux.intel.com
Signed-off-by: Tomita Moeko 
Signed-off-by: Greg Kroah-Hartman

serial: 8250: Fix fifo underflow on flush

2025-03-13T11:43:16+00:00

commit 9e512eaaf8f4008c44ede3dfc0fbc9d9c5118583 upstream.

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 
Signed-off-by: John Keeping 
Link: https://lore.kernel.org/r/20250208124148.1189191-1-jkeeping@inmusicbrands.com
Signed-off-by: Greg Kroah-Hartman

serial: sh-sci: Do not probe the serial port if its slot in sci_ports[] is in use

2025-03-13T11:43:09+00:00

commit 9f7dea875cc7f9c1a56a5c688290634a59cd1420 upstream.

In the sh-sci driver, sci_ports[0] is used by earlycon. If the earlycon is
still active when sci_probe() is called and the new serial port is supposed
to map to sci_ports[0], return -EBUSY to prevent breaking the earlycon.

This situation should occurs in debug scenarios, and users should be
aware of the potential conflict.

Fixes: 0b0cced19ab1 ("serial: sh-sci: Add CONFIG_SERIAL_EARLYCON support")
Cc: stable@vger.kernel.org
Signed-off-by: Claudiu Beznea 
Link: https://lore.kernel.org/r/20250116182249.3828577-4-claudiu.beznea.uj@bp.renesas.com
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Greg Kroah-Hartman

serial: sh-sci: Drop __initdata macro for port_cfg

2025-03-13T11:43:09+00:00

commit eaeee4225dba30bef4d424bdf134a07b7f423e8b upstream.

The port_cfg object is used by serial_console_write(), which serves as
the write function for the earlycon device. Marking port_cfg as __initdata
causes it to be freed after kernel initialization, resulting in earlycon
becoming unavailable thereafter. Remove the __initdata macro from port_cfg
to resolve this issue.

Fixes: 0b0cced19ab1 ("serial: sh-sci: Add CONFIG_SERIAL_EARLYCON support")
Cc: stable@vger.kernel.org
Reviewed-by: Geert Uytterhoeven 
Signed-off-by: Claudiu Beznea 
Fixes: 0b0cced19ab15c9e ("serial: sh-sci: Add CONFIG_SERIAL_EARLYCON support")
Link: https://lore.kernel.org/r/20250116182249.3828577-2-claudiu.beznea.uj@bp.renesas.com
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Greg Kroah-Hartman

serial: 8250: omap: Move pm_runtime_get_sync

2024-12-14T18:44:37+00:00

commit bcc7ba668818dcadd2f1db66b39ed860a63ecf97 upstream.

Currently in omap_8250_shutdown, the dma->rx_running flag is
set to zero in omap_8250_rx_dma_flush. Next pm_runtime_get_sync
is called, which is a runtime resume call stack which can
re-set the flag. When the call omap_8250_shutdown returns, the
flag is expected to be UN-SET, but this is not the case. This
is causing issues the next time UART is re-opened and
omap_8250_rx_dma is called. Fix by moving pm_runtime_get_sync
before the omap_8250_rx_dma_flush.

cc: stable@vger.kernel.org
Fixes: 0e31c8d173ab ("tty: serial: 8250_omap: add custom DMA-RX callback")
Signed-off-by: Bin Liu 
[Judith: Add commit message]
Signed-off-by: Judith Mendez 
Reviewed-by: Kevin Hilman 
Tested-by: Kevin Hilman 
Link: https://lore.kernel.org/r/20241031172315.453750-1-jm@ti.com
Signed-off-by: Greg Kroah-Hartman

Revert "serial: sh-sci: Clean sci_ports[0] after at earlycon exit"

2024-12-14T18:44:36+00:00

commit 718632467d88e98816fa01ab12681ef1c2aa56f8 upstream.

This reverts commit 3791ea69a4858b81e0277f695ca40f5aae40f312.

It was reported to cause boot-time issues, so revert it for now.

Reported-by: Geert Uytterhoeven 
Fixes: 3791ea69a485 ("serial: sh-sci: Clean sci_ports[0] after at earlycon exit")
Cc: stable 
Cc: Claudiu Beznea 
Signed-off-by: Greg Kroah-Hartman

serial: sh-sci: Clean sci_ports[0] after at earlycon exit

2024-12-14T18:44:36+00:00

commit 3791ea69a4858b81e0277f695ca40f5aae40f312 upstream.

The early_console_setup() function initializes the sci_ports[0].port with
an object of type struct uart_port obtained from the object of type
struct earlycon_device received as argument by the early_console_setup().

It may happen that later, when the rest of the serial ports are probed,
the serial port that was used as earlycon (e.g., port A) to be mapped to a
different position in sci_ports[] and the slot 0 to be used by a different
serial port (e.g., port B), as follows:

sci_ports[0] = port A
sci_ports[X] = port B

In this case, the new port mapped at index zero will have associated data
that was used for earlycon.

In case this happens, after Linux boot, any access to the serial port that
maps on sci_ports[0] (port A) will block the serial port that was used as
earlycon (port B).

To fix this, add early_console_exit() that clean the sci_ports[0] at
earlycon exit time.

Fixes: 0b0cced19ab1 ("serial: sh-sci: Add CONFIG_SERIAL_EARLYCON support")
Cc: stable@vger.kernel.org
Signed-off-by: Claudiu Beznea 
Link: https://lore.kernel.org/r/20241106120118.1719888-4-claudiu.beznea.uj@bp.renesas.com
Signed-off-by: Greg Kroah-Hartman