[0/3] Implement ACPI SPCR v3 support and minor earlycon cleanup

Message

Raul Rangel Sept. 12, 2024, 5:36 p.m. UTC

Getting `earlycon` working on AMD platforms is a bit tricky because the
uartclk is 48MHz. If the uartclk isn't specified, we default to
115200*16 which results in an incorrect divisor computation.

This patch set adds the uartclk to the `console=` documentation,
prints a notice to the user that it's using a default uartclk, and
implements support for SPCR v3 so that the uartclk can be provided
by the firmware.


Raul E Rangel (3):
  Documentation: kernel-parameters: Add uartclk to console=uart
  earlycon: Print a notice when uartclk is unknown
  ACPI: SPCR: Add support for rev 3

 Documentation/admin-guide/kernel-parameters.txt | 16 ++++++----------
 drivers/acpi/spcr.c                             |  5 ++++-
 drivers/tty/serial/earlycon.c                   |  6 +++++-
 include/acpi/actbl3.h                           |  6 +++---
 4 files changed, 18 insertions(+), 15 deletions(-)