Re: [PATCH] x86/acpi: Add acpi=spcr to use SPCR-provided default console

Hi,

On 15/1/26 20:00, Borislav Petkov wrote:

On Thu, Jan 15, 2026 at 01:09:40AM +0800, Shenghao Yang wrote:

quoted

We've been inserting the dumped config into the kernel command 
line and rebooting on first boot (e.g. console=uart,io,0x3f8,115200),
but would love to avoid this loop.

Yah, put that in your v2 pls. That's much more understandable.

quoted

It's easier this way for larger fleets - we don't want to manage
hardware specific serial console settings on the kernel command line
if the firmware is already capable of telling us the correct ones.

Should also be in the commit message.

quoted

If earlycon is specified on the command line the console from SPCR
is used, but only as a boot console. It's not present in
/proc/consoles.

It is possible to retain it with keep_bootcon, but that uses the
less efficient (in the 8250 case) 8250_early driver.

Also for the commit message.

quoted

In 0231d00082f6 ("ACPI: SPCR: Make SPCR available to x86") the SPCR
console is only added as an option for earlycon but not as an ordinary
console so users don't see console output changes.  

The patch adds an opt in so we can get the SPCR console added as
an ordinary console.

Yap, your explanations make much more sense, thanks.

Please structure your v2 something like this boilerplate guidance below:

1. Prepare the context for the explanation briefly.

2. Explain the problem at hand.

3. "It happens because of <...>"

4. "Fix it by doing X"

5. "(Potentially do Y)."

And some of those above are optional depending on the issue being
explained.

For more detailed info, see
Documentation/process/submitting-patches.rst,
Section "2) Describe your changes".

Also, to the tone, from Documentation/process/submitting-patches.rst:

 "Describe your changes in imperative mood, e.g. "make xyzzy do frotz"
  instead of "[This patch] makes xyzzy do frotz" or "[I] changed xyzzy
  to do frotz", as if you are giving orders to the codebase to change
  its behaviour."

Also, do not talk about what your patch does - that should (hopefully) be
visible from the diff itself. Rather, talk about *why* you're doing what
you're doing.

Thanks! I'll reword and send v2.

Shenghao