kernel.git/drivers/tty/serial/8250, branch linux-5.10.y

serial: 8250: 8250_omap.c: Clear DMA RX running status only after DMA termination is done

2026-03-04T12:20:06Z

[ Upstream commit a5fd8945a478ff9be14812693891d7c9b4185a50 ] Clear rx_running flag only after DMA teardown polling completes. In the previous implementation the flag was being cleared while hardware teardown was still in progress, creating a mismatch between software state (flag = 0, "ready") and hardware state (still terminating). Signed-off-by: Moteen Shah Link: https://patch.msgid.link/20260112081829.63049-3-m-shah@ti.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin

serial: 8250_dw: handle clock enable errors in runtime_resume

2026-03-04T12:20:06Z

[ Upstream commit d31228143a489ba6ba797896a07541ce06828c09 ] Add error checking for clk_prepare_enable() calls in dw8250_runtime_resume(). Currently if either clock fails to enable, the function returns success while leaving clocks in inconsistent state. This change implements comprehensive error handling by checking the return values of both clk_prepare_enable() calls. If the second clock enable operation fails after the first clock has already been successfully enabled, the code now properly cleans up by disabling and unpreparing the first clock before returning. The error code is then propagated to the caller, ensuring that clock enable failures are properly reported rather than being silently ignored. Signed-off-by: Artem Shimko Link: https://patch.msgid.link/20251104145433.2316165-2-a.shimko.dev@gmail.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin

serial: add support of CPCI cards

2026-01-19T12:11:25Z

commit 0e5a99e0e5f50353b86939ff6e424800d769c818 upstream. Addi-Data GmbH is manufacturing multi-serial ports cards supporting CompactPCI (known as CPCI). Those cards are identified with different DeviceIds. Those cards integrating standard UARTs work the same way as PCI/PCIe models already supported in the serial driver. Signed-off-by: Magne Bruno Link: https://patch.msgid.link/20251110162456.341029-1-magne.bruno@addi-data.com Cc: stable Signed-off-by: Greg Kroah-Hartman

serial: 8250_dw: handle reset control deassert error

2025-12-06T21:08:08Z

[ Upstream commit daeb4037adf7d3349b4a1fb792f4bc9824686a4b ] Check the return value of reset_control_deassert() in the probe function to prevent continuing probe when reset deassertion fails. Previously, reset_control_deassert() was called without checking its return value, which could lead to probe continuing even when the device reset wasn't properly deasserted. The fix checks the return value and returns an error with dev_err_probe() if reset deassertion fails, providing better error handling and diagnostics. Fixes: acbdad8dd1ab ("serial: 8250_dw: simplify optional reset handling") Cc: stable Signed-off-by: Artem Shimko Link: https://patch.msgid.link/20251019095131.252848-1-a.shimko.dev@gmail.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

serial: 8250_dw: Use devm_add_action_or_reset()

2025-12-06T21:08:08Z

[ Upstream commit 295b09128d12fb1a7a67f771cc0ae0df869eafaf ] Slightly simplify ->probe() and drop a few goto labels by using devm_add_action_or_reset() for clock and reset cleanup. Signed-off-by: Andy Shevchenko Link: https://lore.kernel.org/r/20220509172129.37770-1-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman Stable-dep-of: daeb4037adf7 ("serial: 8250_dw: handle reset control deassert error") Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

serial: 8250_exar: add support for Advantech 2 port card with Device ID 0x0018

2025-10-29T13:01:23Z

commit e7cbce761fe3fcbcb49bcf30d4f8ca5e1a9ee2a0 upstream. The Advantech 2-port serial card with PCI vendor=0x13fe and device=0x0018 has a 'XR17V35X' chip installed on the circuit board. Therefore, this driver can be used instead of theu outdated out-of-tree driver from the manufacturer. Signed-off-by: Florian Eckert Cc: stable Link: https://patch.msgid.link/20250924134115.2667650-1-fe@dev.tdt.de Signed-off-by: Greg Kroah-Hartman

serial: 8250: fix panic due to PSLVERR

2025-08-28T14:22:48Z

commit 7f8fdd4dbffc05982b96caf586f77a014b2a9353 upstream. When the PSLVERR_RESP_EN parameter is set to 1, the device generates an error response if an attempt is made to read an empty RBR (Receive Buffer Register) while the FIFO is enabled. In serial8250_do_startup(), calling serial_port_out(port, UART_LCR, UART_LCR_WLEN8) triggers dw8250_check_lcr(), which invokes dw8250_force_idle() and serial8250_clear_and_reinit_fifos(). The latter function enables the FIFO via serial_out(p, UART_FCR, p->fcr). Execution proceeds to the serial_port_in(port, UART_RX). This satisfies the PSLVERR trigger condition. When another CPU (e.g., using printk()) is accessing the UART (UART is busy), the current CPU fails the check (value & ~UART_LCR_SPAR) == (lcr & ~UART_LCR_SPAR) in dw8250_check_lcr(), causing it to enter dw8250_force_idle(). Put serial_port_out(port, UART_LCR, UART_LCR_WLEN8) under the port->lock to fix this issue. Panic backtrace: [ 0.442336] Oops - unknown exception [#1] [ 0.442343] epc : dw8250_serial_in32+0x1e/0x4a [ 0.442351] ra : serial8250_do_startup+0x2c8/0x88e ... [ 0.442416] console_on_rootfs+0x26/0x70 Fixes: c49436b657d0 ("serial: 8250_dw: Improve unwritable LCR workaround") Link: https://lore.kernel.org/all/84cydt5peu.fsf@jogness.linutronix.de/T/ Signed-off-by: Yunhui Cui Reviewed-by: John Ogness Cc: stable Link: https://lore.kernel.org/r/20250723023322.464-2-cuiyunhui@bytedance.com [ Applied fix to serial8250_do_startup() instead of serial8250_initialize() ] Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

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

2025-04-10T12:30:54Z

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

2025-04-10T12:30:54Z

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

2025-03-13T11:47:23Z

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