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

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <b2584ec9-8593-46d6-aff7-5a1f6081c9ae@shenghaoyang.info>
Date: Sat, 17 Jan 2026 15:06:11 +0800
From: Shenghao Yang <me@...nghaoyang.info>
To: Borislav Petkov <bp@...en8.de>
Cc: x86@...nel.org, Jonathan Corbet <corbet@....net>,
 "Rafael J. Wysocki" <rafael@...nel.org>, Len Brown <lenb@...nel.org>,
 Thomas Gleixner <tglx@...utronix.de>, Ingo Molnar <mingo@...hat.com>,
 Dave Hansen <dave.hansen@...ux.intel.com>, "H. Peter Anvin" <hpa@...or.com>,
 linux-doc@...r.kernel.org, linux-kernel@...r.kernel.org,
 linux-acpi@...r.kernel.org
Subject: 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:
>> 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.
> 
>> 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.
> 
>> 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.
> 
>> 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