Re: Blank screen on boot of Linux 6.5 and later on Lenovo ThinkPad L570

[Huacai Chen]

On Fri, Oct 20, 2023 at 5:35 PM Linux regression tracking (Thorsten
Leemhuis) <regressions@xxxxxxxxxxxxx> wrote:
>
> On 09.10.23 10:54, Huacai Chen wrote:
> > On Mon, Oct 9, 2023 at 4:45 PM Bagas Sanjaya <bagasdotme@xxxxxxxxx> wrote:
> >> On Mon, Oct 09, 2023 at 09:27:02AM +0800, Huacai Chen wrote:
> >>> On Tue, Sep 26, 2023 at 10:31 PM Huacai Chen <chenhuacai@xxxxxxxxxx> wrote:
> >>>> On Tue, Sep 26, 2023 at 7:15 PM Linux regression tracking (Thorsten
> >>>> Leemhuis) <regressions@xxxxxxxxxxxxx> wrote:
> >>>>> On 13.09.23 14:02, Jaak Ristioja wrote:
> >>>>>>
> >>>>>> Upgrading to Linux 6.5 on a Lenovo ThinkPad L570 (Integrated Intel HD
> >>>>>> Graphics 620 (rev 02), Intel(R) Core(TM) i7-7500U) results in a blank
> >>>>>> screen after boot until the display manager starts... if it does start
> >>>>>> at all. Using the nomodeset kernel parameter seems to be a workaround.
> >>>>>>
> >>>>>> I've bisected this to commit 60aebc9559492cea6a9625f514a8041717e3a2e4
> >>>>>> ("drivers/firmware: Move sysfb_init() from device_initcall to
> >>>>>> subsys_initcall_sync").
> >>>>>
> >>>>> Hmmm, no reaction since it was posted a while ago, unless I'm missing
> >>>>> something.
> >>>>>
> >>>>> Huacai Chen, did you maybe miss this report? The problem is apparently
> >>>>> caused by a commit of yours (that Javier applied), you hence should look
> >>>>> into this.
> >>>> I'm sorry but it looks very strange, could you please share your config file?
> >>> As confirmed by Jaak, disabling DRM_SIMPLEDRM makes things work fine
> >>> again. So I guess the reason:
> >>
> >> Did Jaak reply privately? It should have been disclosed in public
> >> ML here instead.
> > Yes, he replied privately, and disabling DRM_SIMPLEDRM was suggested by me.
>
> Well, this to me still looks a lot (please correct me if I'm wrong) like
> regression that should be fixed, as DRM_SIMPLEDRM was enabled beforehand
> if I understood things correctly. Or is there a proper fix for this
> already in the works and I just missed this? Or is there some good
> reason why this won't/can't be fixed?
DRM_SIMPLEDRM was enabled but it didn't work at all because there was
no corresponding platform device. Now DRM_SIMPLEDRM works but it has a
blank screen. Of course it is valuable to investigate further about
DRM_SIMPLEDRM on Jaak's machine, but that needs Jaak's effort because
I don't have a same machine.

Huacai
>
> Ciao, Thorsten (wearing his 'the Linux kernel's regression tracker' hat)
> --
> Everything you wanna know about Linux kernel regression tracking:
> https://linux-regtracking.leemhuis.info/about/#tldr
> If I did something stupid, please tell me, as explained on that page.
>
> #regzbot poke
>
> >>> When SIMPLEDRM takes over the framebuffer, the screen is blank (don't
> >>> know why). And before 60aebc9559492cea6a9625f ("drivers/firmware: Move
> >>> sysfb_init() from device_initcall to subsys_initcall_sync") there is
> >>> no platform device created for SIMPLEDRM at early stage, so it seems
> >>> also "no problem".
> >>
> >> I don't understand above. You mean that after that commit the platform
> >> device is also none, right?
> > No. The SIMPLEDRM driver needs a platform device to work, and that
> > commit makes the platform device created earlier. So, before that
> > commit, SIMPLEDRM doesn't work, but the screen isn't blank; after that
> > commit, SIMPLEDRM works, but the screen is blank.
> >
> > Huacai
> >>
> >> Confused...
> >>
> >> --
> >> An old man doll... just what I always wanted! - Clara
> >
> >