kernel/drivers/tty/serial, branch linux-6.9.y

serial: imx: ensure RTS signal is not left active after shutdown

2024-07-18T11:22:50Z

commit 1af2156e58f3af1216ce2f0456b3b8949faa5c7e upstream. If a process is killed while writing to a /dev/ttymxc* device in RS485 mode, we observe that the RTS signal is left high, thus making it impossible for other devices to transmit anything. Moreover, the ->tx_state variable is left in state SEND, which means that when one next opens the device and configures baud rate etc., the initialization code in imx_uart_set_termios dutifully ensures the RTS pin is pulled down, but since ->tx_state is already SEND, the logic in imx_uart_start_tx() does not in fact pull the pin high before transmitting, so nothing actually gets on the wire on the other side of the transceiver. Only when that transmission is allowed to complete is the state machine then back in a consistent state. This is completely reproducible by doing something as simple as seq 10000 > /dev/ttymxc0 and hitting ctrl-C, and watching with a logic analyzer. Signed-off-by: Rasmus Villemoes Cc: stable Reviewed-by: Marek Vasut Link: https://lore.kernel.org/r/20240625184206.508837-1-linux@rasmusvillemoes.dk Signed-off-by: Greg Kroah-Hartman

tty: serial: ma35d1: Add a NULL check for of_node

2024-07-18T11:22:50Z

commit acd09ac253b5de8fd79fc61a482ee19154914c7a upstream. The pdev->dev.of_node can be NULL if the "serial" node is absent. Add a NULL check to return an error in such cases. Fixes: 930cbf92db01 ("tty: serial: Add Nuvoton ma35d1 serial driver support") Reported-by: Dan Carpenter Closes: https://lore.kernel.org/all/8df7ce45-fd58-4235-88f7-43fe7cd67e8f@moroto.mountain/ Signed-off-by: Jacky Huang Reviewed-by: Dan Carpenter Cc: stable Link: https://lore.kernel.org/r/20240625064128.127-1-ychuang570808@gmail.com Signed-off-by: Greg Kroah-Hartman

serial: imx: Raise TX trigger level to 8

2024-07-11T10:51:05Z

[ Upstream commit a3d8728ab079951741efa11360df43dbfacba7ab ] At the default TX trigger level of 2 in non-DMA mode (meaning that an interrupt is generated when less than 2 characters are left in the FIFO), we have observed frequent buffer underruns at 115200 Baud on an i.MX8M Nano. This can cause communication issues if the receiving side expects a continuous transfer. Increasing the level to 8 makes the UART trigger an interrupt earlier, giving the kernel enough time to refill the FIFO, at the cost of triggering one interrupt per ~24 instead of ~30 bytes of transmitted data (as the i.MX UART has a 32 byte FIFO). Signed-off-by: Michael Krummsdorf Signed-off-by: Matthias Schiffer Link: https://lore.kernel.org/r/20240508133744.35858-1-matthias.schiffer@ew.tq-group.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin

serial: 8250_omap: Fix Errata i2310 with RX FIFO level check

2024-07-05T07:38:20Z

commit c128a1b0523b685c8856ddc0ac0e1caef1fdeee5 upstream. Errata i2310[0] says, Erroneous timeout can be triggered, if this Erroneous interrupt is not cleared then it may leads to storm of interrupts. Commit 9d141c1e6157 ("serial: 8250_omap: Implementation of Errata i2310") which added the workaround but missed ensuring RX FIFO is really empty before applying the errata workaround as recommended in the errata text. Fix this by adding back check for UART_OMAP_RX_LVL to be 0 for workaround to take effect. [0] https://www.ti.com/lit/pdf/sprz536 page 23 Fixes: 9d141c1e6157 ("serial: 8250_omap: Implementation of Errata i2310") Cc: stable@vger.kernel.org Reported-by: Vignesh Raghavendra Closes: https://lore.kernel.org/all/e96d0c55-0b12-4cbf-9d23-48963543de49@ti.com/ Signed-off-by: Udit Kumar Link: https://lore.kernel.org/r/20240625160725.2102194-1-u-kumar1@ti.com Signed-off-by: Greg Kroah-Hartman

serial: imx: only set receiver level if it is zero

2024-07-05T07:38:20Z

commit 9706fc87b4cff0ac4f5d5d62327be83fe72e3108 upstream. With commit a81dbd0463ec ("serial: imx: set receiver level before starting uart") we set the receiver level to its default value. This caused a regression when using SDMA, where the receiver level is 9 instead of 8 (default). This change will first check if the receiver level is zero and only then set it to the default. This still avoids the interrupt storm when the receiver level is zero. Fixes: a81dbd0463ec ("serial: imx: set receiver level before starting uart") Cc: stable Signed-off-by: Stefan Eichenberger Link: https://lore.kernel.org/r/20240703112543.148304-1-eichest@gmail.com Signed-off-by: Greg Kroah-Hartman

tty: mcf: MCF54418 has 10 UARTS

2024-07-05T07:38:11Z

commit 7c92a8bd53f24d50c8cf4aba53bb75505b382fed upstream. Most of the colfires have up to 5 UARTs but MCF54418 has up-to 10 ! Change the maximum value authorized. Signed-off-by: Jean-Michel Hautbois Cc: stable Fixes: 2545cf6e94b4 ("m68knommu: allow 4 coldfire serial ports") Link: https://lore.kernel.org/r/20240620-upstream-uart-v1-1-a9d0d95fb19e@yoseli.org Signed-off-by: Greg Kroah-Hartman

serial: bcm63xx-uart: fix tx after conversion to uart_port_tx_limited()

2024-07-05T07:38:11Z

commit ea55c65dedf40e9c1911dc1e63e26bc9a59692b9 upstream. When bcm63xx-uart was converted to uart_port_tx_limited(), it implicitly added a call to stop_tx(). This causes garbage to be put out on the serial console. To fix this, pass UART_TX_NOSTOP in flags, and manually call stop_tx() ourselves analogue to how a similar issue was fixed in commit 7be50f2e8f20 ("serial: mxs-auart: fix tx"). Fixes: d11cc8c3c4b6 ("tty: serial: use uart_port_tx_limited()") Cc: stable@vger.kernel.org Signed-off-by: Jonas Gorski Signed-off-by: Doug Brown Link: https://lore.kernel.org/r/20240606195632.173255-4-doug@schmorgal.com Signed-off-by: Greg Kroah-Hartman

serial: imx: set receiver level before starting uart

2024-07-05T07:38:10Z

commit a81dbd0463eca317eee44985a66aa6cc2ce5c101 upstream. Set the receiver level to something > 0 before calling imx_uart_start_rx in rs485_config. This is necessary to avoid an interrupt storm that might prevent the system from booting. This was seen on an i.MX7 device when the rs485-rts-active-low property was active in the device tree. Fixes: 6d215f83e5fc ("serial: imx: warn user when using unsupported configuration") Cc: stable Signed-off-by: Stefan Eichenberger Link: https://lore.kernel.org/r/20240621153829.183780-1-eichest@gmail.com Signed-off-by: Greg Kroah-Hartman

serial: 8250_omap: Implementation of Errata i2310

2024-07-05T07:38:10Z

commit 9d141c1e615795eeb93cd35501ad144ee997a826 upstream. As per Errata i2310[0], Erroneous timeout can be triggered, if this Erroneous interrupt is not cleared then it may leads to storm of interrupts, therefore apply Errata i2310 solution. [0] https://www.ti.com/lit/pdf/sprz536 page 23 Fixes: b67e830d38fa ("serial: 8250: 8250_omap: Fix possible interrupt storm on K3 SoCs") Cc: stable@vger.kernel.org Signed-off-by: Udit Kumar Link: https://lore.kernel.org/r/20240619105903.165434-1-u-kumar1@ti.com Signed-off-by: Greg Kroah-Hartman

tty: serial: 8250: Fix port count mismatch with the device

2024-07-05T07:38:10Z

commit 0ac18dac43103ab1df6d26ec9a781c0126f83ced upstream. Normally, the number of ports is indicated by the third digit of the device ID on Moxa PCI serial boards. For example, `0x1121` indicates a device with 2 ports. However, `CP116E_A_A` and `CP116E_A_B` are exceptions; they have 8 ports, but the third digit of the device ID is `6`. This patch introduces a function to retrieve the number of ports on Moxa PCI serial boards, addressing the issue described above. Fixes: 37058fd5d239 ("tty: serial: 8250: Add support for MOXA Mini PCIe boards") Cc: stable Signed-off-by: Crescent Hsieh Reviewed-by: Andy Shevchenko Link: https://lore.kernel.org/r/20240617063058.18866-1-crescentcy.hsieh@moxa.com Signed-off-by: Greg Kroah-Hartman