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From: Laura Nao <laura.nao@collabora.com>
To: tglx@linutronix.de
Cc: kernel@collabora.com,
	laura.nao@collabora.com,
	linux-kernel@vger.kernel.org,
	regressions@leemhuis.info,
	regressions@lists.linux.dev,
	x86@kernel.org
Subject: Re: [REGRESSION] mainline boot regression on AMD Stoney Ridge Chromebooks
Date: Fri,  5 Apr 2024 12:32:33 +0200
Message-Id: <20240405103233.268999-1-laura.nao@collabora.com>
In-Reply-To: <877chc9p4l.ffs@tglx>
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On 4/5/24 10:42, Thomas Gleixner wrote:
> Laura!
> 
> On Fri, Apr 05 2024 at 10:14, Laura Nao wrote:
>> On 4/4/24 22:05, Thomas Gleixner wrote:
>>> Can I get the /proc/cpuinfo output please?
>>
>> Here are more logs from the same device running v6.8:
>> - cpuid -r: https://pastebin.com/raw/YmDrnw06
>> - cpuinfo: https://pastebin.com/raw/Ki0vwdDE
> 
> Thanks for the info. I'm still not seing why that wouldn't work.
> 
> As the machine seems to have a serial port, can you please replace
> 'earlycon' with 'earlyprintk=ttyS0,115200' on the command line and see
> whether that gives some output. I'm not sure that the current 'earlycon'
> has the same effect.
> 

Thanks for the hint - replacing earlycon with earlyprintk=ttyS0,115200 
doesn't seem to help unfortunately, I still get no output at all.

Not sure if it's really relevant to mention, but when booting a v6.8
kernel the first stage bootloader (i.e. coreboot in this case) spits out
a few lines before the kernel takes over:

coreboot-v1.9308_26_0.0.22-6034-gd586c7b122 Wed Jul 15 17:51:44 UTC 2020 smm starting...
SMI# #0
Chrome EC: Set SMI mask to 0x0000000000000000
Chrome EC: UHEPI supported
Clearing pending EC events. Error code 1 is expected.
EC returned error result code 9
Chrome EC: Set SCI mask to 0x00000000142609fb

When booting e.g. next-20240404 not even these lines are reported after
'Starting Kernel...'. Not sure if that suggests anything significant
though.

For the sake of completeness, I'm leaving here links to the full test
jobs run in our Collabora LAVA lab, to include everything that's reported
on the serial console after the device is powered on:
- v6.8 test job: https://lava.collabora.dev/scheduler/job/13265735#L279
- next-20240404 test job w/ 'earlyprintk=ttyS0,115200' in cmdline:
https://lava.collabora.dev/scheduler/job/13266992#L279

I also tried applying the patch you attached above on top of
next-20240404 but it doesn't seem to make any difference unfortunately.

Best,

Laura