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

[Huacai Chen]

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:
> > Hi, all,
> >
> > On Tue, Sep 26, 2023 at 10:31 PM Huacai Chen <chenhuacai@xxxxxxxxxx> wrote:
> > >
> > > Hi, all,
> > >
> > > On Tue, Sep 26, 2023 at 7:15 PM Linux regression tracking (Thorsten
> > > Leemhuis) <regressions@xxxxxxxxxxxxx> wrote:
> > > >
> > > > [CCing the regression list, as it should be in the loop for regressions:
> > > > https://docs.kernel.org/admin-guide/reporting-regressions.html]
> > > >
> > > > Hi, Thorsten here, the Linux kernel's regression tracker.
> > > >
> > > > 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.

>
> >
> > 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