Re: 5.15 regression: CONFIG_SYSFB_SIMPLEFB breaks console scrolling

Re: 5.15 regression: CONFIG_SYSFB_SIMPLEFB breaks console scrolling

[Thorsten Leemhuis]

Hi, this is your Linux kernel regression tracker speaking.

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.

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:

https://linux-regtracking.leemhuis.info/regzbot/
https://gitlab.com/knurd42/regzbot/-/blob/main/docs/getting_started.md
https://gitlab.com/knurd42/regzbot/-/blob/main/docs/reference.md

The last two documents will explain how you can interact with regzbot
yourself if your want to.

Hint for the reporter: when reporting a regression it's in your interest
to tell #regzbot about it in the report, as that will ensure the
regression gets on the radar of regzbot and the regression tracker.
That's in your interest, as they will make sure the report won't fall
through the cracks unnoticed.

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

Re: 5.15 regression: CONFIG_SYSFB_SIMPLEFB breaks console scrolling

[Thorsten Leemhuis]

On 21.11.21 12:47, Thorsten Leemhuis wrote:
> Hi, this is your Linux kernel regression tracker speaking.

/me again

> 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.

Ciao, Thorsten

> 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:
> 
> https://linux-regtracking.leemhuis.info/regzbot/
> https://gitlab.com/knurd42/regzbot/-/blob/main/docs/getting_started.md
> https://gitlab.com/knurd42/regzbot/-/blob/main/docs/reference.md
> 
> The last two documents will explain how you can interact with regzbot
> yourself if your want to.
> 
> Hint for the reporter: when reporting a regression it's in your interest
> to tell #regzbot about it in the report, as that will ensure the
> regression gets on the radar of regzbot and the regression tracker.
> That's in your interest, as they will make sure the report won't fall
> through the cracks unnoticed.
> 
> 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

Re: 5.15 regression: CONFIG_SYSFB_SIMPLEFB breaks console scrolling

[Thorsten Leemhuis]

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:
>>
>> https://linux-regtracking.leemhuis.info/regzbot/
>> https://gitlab.com/knurd42/regzbot/-/blob/main/docs/getting_started.md
>> https://gitlab.com/knurd42/regzbot/-/blob/main/docs/reference.md
>>
>> The last two documents will explain how you can interact with regzbot
>> yourself if your want to.
>>
>> Hint for the reporter: when reporting a regression it's in your interest
>> to tell #regzbot about it in the report, as that will ensure the
>> regression gets on the radar of regzbot and the regression tracker.
>> That's in your interest, as they will make sure the report won't fall
>> through the cracks unnoticed.
>>
>> 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
> 
> 
> 
> 

Re: 5.15 regression: CONFIG_SYSFB_SIMPLEFB breaks console scrolling

[Javier Martinez Canillas]

Sorry for the late reply.

On 11/21/21 12:47, Thorsten Leemhuis wrote:
> Hi, this is your Linux kernel regression tracker speaking.
> 
> 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.
>

I don't think this is a regression since enabling CONFIG_SYSFB_SIMPLEFB will
make the simpledrm driver to be bound while disabling the option makes the
efifb driver to be bound instead.
 Yes, it seems to be a bug in the simpledrm driver but the solution if you
have issues with the simpledrm is to not enable CONFIG_SYSFB_SIMPLEFB and
keep using the old fbdev driver.

Best regards,
-- 
Javier Martinez Canillas
Linux Engineering
Red Hat

Re: 5.15 regression: CONFIG_SYSFB_SIMPLEFB breaks console scrolling

[Thorsten Leemhuis]

Hi, this is your Linux kernel regression tracker speaking.

On 03.12.21 12:20, Javier Martinez Canillas wrote:
> Sorry for the late reply.
> 
> On 11/21/21 12:47, Thorsten Leemhuis wrote:
>> Hi, this is your Linux kernel regression tracker speaking.
>>
>> 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.
> 
> I don't think this is a regression since enabling CONFIG_SYSFB_SIMPLEFB will
> make the simpledrm driver to be bound while disabling the option makes the
> efifb driver to be bound instead.
>  Yes, it seems to be a bug in the simpledrm driver but the solution if you
> have issues with the simpledrm is to not enable CONFIG_SYSFB_SIMPLEFB and
> keep using the old fbdev driver.

Mandy thx for the answer, Javier. Harald is quiet for some time already
and didn't object so far, hence I'll remove this from regzbot:

#regzbot invalid: problem caused by a new CONFIG option

Ciao, Thorsten

P.S.: As a Linux kernel regression tracker I'm getting a lot of reports
on my table. I can only look briefly into most of them. Unfortunately
therefore I sometimes will get things wrong or miss something important.
I hope that's not the case here; if you think it is, don't hesitate to
tell me about it in a public reply. That's in everyone's interest, as
what I wrote above might be misleading to everyone reading this; any
suggestion I gave they thus might sent someone reading this down the
wrong rabbit hole, which none of us wants.

BTW, I have no personal interest in this issue, which is tracked using
regzbot, my Linux kernel regression tracking bot
(https://linux-regtracking.leemhuis.info/regzbot/). I'm only posting
this mail to get things rolling again and hence don't need to be CC on
all further activities wrt to this regression.