kernel/linux.git/drivers/acpi/spcr.c, branch linux-7.1.y

ACPI: SPCR: Check for table version when using precise baudrate

2025-10-27T19:43:41+00:00

Commit 4d330fe54145 ("ACPI: SPCR: Support Precise Baud Rate field") added support to use the precise baud rate available since SPCR 1.09 (revision 4) but failed to check the version of the table provided by the firmware. Accessing an older version of SPCR table causes accesses beyond the end of the table and can lead to garbage data to be used for the baud rate. Check the version of the firmware provided SPCR to ensure that the precise baudrate is vaild before using it. Fixes: 4d330fe54145 ("ACPI: SPCR: Support Precise Baud Rate field") Signed-off-by: Punit Agrawal Link: https://patch.msgid.link/20251024123125.1081612-1-punit.agrawal@oss.qualcomm.com Signed-off-by: Rafael J. Wysocki

ACPI: SPCR: Support Precise Baud Rate field

2025-09-22T17:13:08+00:00

The Microsoft Serial Port Console Redirection (SPCR) specification revision 1.09 comprises additional field: Precise Baud Rate [1]. It is used to describe non-traditional baud rates (such as those used by high-speed UARTs). It contains a specific non-zero baud rate which overrides the value of the Configured Baud Rate field. If this field is zero or not present, Configured Baud Rate is used. Link: https://learn.microsoft.com/en-us/windows-hardware/drivers/serports/serial-port-console-redirection-table [1] Signed-off-by: Chen Pei Link: https://patch.msgid.link/20250913070815.16758-1-cp0613@linux.alibaba.com [ rjw: Corrected typo in the subject ] Signed-off-by: Rafael J. Wysocki

ACPI: SPCR: Add support for DBG2 RISC-V SBI port subtype

2025-09-15T19:37:40+00:00

Commit 4aca2bef90bd1296 ("ACPICA: Headers: Add RISC-V SBI Subtype to DBG2") added the definition of ACPI_DBG2_RISCV_SBI_CON. Continue to implement its function so that the parameters of UART can be configured correctly. Subsequent calls to setup_earlycon() will reuse the earlycon based on SBI. Signed-off-by: Chen Pei Reviewed-by: Guo Ren (Alibaba Damo Academy) Link: https://patch.msgid.link/20250910094136.4423-1-cp0613@linux.alibaba.com [ rjw: Changelog edits ] Signed-off-by: Rafael J. Wysocki

ACPI: SPCR: Amend indentation

2023-03-27T18:50:28+00:00

1) Remove unnecessary blank lines. 2) Reformat one comment for consistency. Signed-off-by: Andy Shevchenko Signed-off-by: Rafael J. Wysocki

ACPI: SPCR: Prefix error messages with FW_BUG

2023-03-22T18:46:49+00:00

The table values that are not defined in the specification are considered non-fatal errors in the code. However, they are firmware bugs, so point this out in the messages by prefixing them with FW_BUG. Signed-off-by: Andy Shevchenko Signed-off-by: Rafael J. Wysocki

ACPI: SPCR: Add support for NVIDIA 16550-compatible port subtype

2022-04-13T18:37:29+00:00

Add support for the NVIDIA specific 16550 subtype to SPCR table parsing routine. Signed-off-by: Jeff Brasen Signed-off-by: Jon Hunter Signed-off-by: Rafael J. Wysocki

ACPI: SPCR: check if table->serial_port.access_width is too wide

2022-01-11T15:39:14+00:00

If table->serial_port.access_width is more than 29, it causes undefined behavior when ACPI_ACCESS_BIT_WIDTH shifts it to (1 << ((size) + 2)): [ 0.000000] UBSAN: Undefined behaviour in drivers/acpi/spcr.c:114:11 [ 0.000000] shift exponent 102 is too large for 32-bit type 'int' Use the new ACPI_ACCESS_ defines to test that serial_port.access_width is less than 30 and set it to 6 if it is not. Signed-off-by: Mark Langsdorf Signed-off-by: Rafael J. Wysocki

ACPI: SPCR: Add support for the new 16550-compatible Serial Port Subtype

2021-08-16T16:38:08+00:00

The Microsoft Debug Port Table 2 (DBG2) specification revision May 31, 2017 added definition of the 16550-compatible Serial Port Subtype with parameters defined in Generic Address Structure (GAS) [1] Add its support in the SPCR table parsing routine. [1] https://docs.microsoft.com/en-us/windows-hardware/drivers/bringup/acpi-debug-port-table Signed-off-by: Marcin Wojtas Signed-off-by: Rafael J. Wysocki

ACPI: Use fallthrough pseudo-keyword

2020-07-09T12:09:28+00:00

Replace the existing /* fall through */ comments and its variants with the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary fall-through markings when it is the case. Link: https://www.kernel.org/doc/html/latest/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through # [1] Signed-off-by: Gustavo A. R. Silva Signed-off-by: Rafael J. Wysocki

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500

2019-06-19T15:09:55+00:00

Based on 2 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license version 2 as published by the free software foundation this program is free software you can redistribute it and or modify it under the terms of the gnu general public license version 2 as published by the free software foundation # extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 4122 file(s). Signed-off-by: Thomas Gleixner Reviewed-by: Enrico Weigelt Reviewed-by: Kate Stewart Reviewed-by: Allison Randal Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de Signed-off-by: Greg Kroah-Hartman