Re: 5.15 regression: CONFIG_SYSFB_SIMPLEFB breaks console scrolling

From: Thorsten Leemhuis <regressions@leemhuis.info>
To: Harald Dunkel <harri@afaics.de>,
	Javier Martinez Canillas <javierm@redhat.com>
Cc: Kernel Mailing List <linux-kernel@vger.kernel.org>,
	dri-devel@lists.freedesktop.org,
	Thomas Zimmermann <tzimmermann@suse.de>,
	"regressions@lists.linux.dev" <regressions@lists.linux.dev>
Subject: Re: 5.15 regression: CONFIG_SYSFB_SIMPLEFB breaks console scrolling
Date: Fri, 3 Dec 2021 11:40:04 +0100	[thread overview]
Message-ID: <bf5d157b-4661-3549-5c90-e28be1846e70@leemhuis.info> (raw)
In-Reply-To: <d9acb4ba-691b-3496-f77b-175c441f887d@leemhuis.info>

On 25.11.21 13:00, Thorsten Leemhuis wrote:
> On 21.11.21 12:47, Thorsten Leemhuis wrote:
>> Hi, this is your Linux kernel regression tracker speaking.
> /me again

and again :-D

>> On 16.11.21 05:52, Harald Dunkel wrote:
>>>
>>> if I enable CONFIG_SYSFB_SIMPLEFB in 5.15.2 and use grub's default
>>> configuration
>>> (Debian sid amd64), then a few lines at the bottom of /dev/tty1 including
>>> login prompt are off-screen. Scrolling is broken. I can login, though.
>>>
>>> Enabling GRUB_TERMINAL=console in grub doesn't make a difference. Using
>>> the same kernel except for CONFIG_SYSFB_SIMPLEFB the problem is gone.
>>>
>>> Graphics card is a GeForce GTX 1650. I tried with both CONFIG_DRM_NOUVEAU
>>> and proprietary graphics drivers disabled.
>>>
>>> Attached you can find the config file. Please mail if I can help to track
>>> this problem down.
>>
>> Thx for the report. I'm not totally sure if this is a regression, as
>> that's a new config option. But it might be one considered a successor
>> to an older one, hence it might count as regression. Adding two
>> developers and a mailing list to the CC, hopefully someone can clarify.
> 
> Javier, I'd be interested in your option on this.
> 
> Harald, did you have CONFIG_X86_SYSFB enabled in earlier kernel versions
> (and did console scrolling work then)? The answer would help me to
> decide if this a regression, as those ideally should be fixed as quickly
> as possible.

Harald, a reply would have been very helpful; I wonder if Javier is
waiting for the answer, too. If I get none in the next few days I guess
I'll drop this from the list of tracked regressions.

Ciao, Thorsten

#regzbot ignore-activity

>> TWIMC: To be sure this issue doesn't fall through the cracks unnoticed,
>> I'm adding it to regzbot, my Linux kernel regression tracking bot:
>>
>> #regzbot ^introduced 8633ef82f101c040427b57d4df7b706261420b94
>> #regzbot title CONFIG_SYSFB_SIMPLEFB breaks console scrolling
>> #regzbot ignore-activity
>>
>> Ciao, Thorsten, your Linux kernel regression tracker.
>>
>> P.S.: If you want to know more about regzbot, check out its
>> web-interface, the getting start guide, and/or the references documentation:
>>
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>>
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>> That's in your interest, as they will make sure the report won't fall
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>>
>> Hint for developers: you normally don't need to care about regzbot, just
>> fix the issue as you normally would. Just remember to include a 'Link:'
>> tag to the report in the commit message, as explained in
>> Documentation/process/submitting-patches.rst
>> That aspect was recently was made more explicit in commit 1f57bd42b77c:
>> https://git.kernel.org/linus/1f57bd42b77c
> 
> #regzbot title drm: CONFIG_SYSFB_SIMPLEFB breaks console scrolling
> 
> 
> 
> 