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In-Reply-To: <c9b79a69-bdc1-4457-900d-709a15d99568@leemhuis.info>
From:   Huacai Chen <chenhuacai@kernel.org>
Date:   Fri, 20 Oct 2023 17:48:31 +0800
Message-ID: <CAAhV-H4qQW_fOdkTxmT1xbvo4LOapzw_tOw7Kma47xmh0PvpPA@mail.gmail.com>
Subject: Re: Blank screen on boot of Linux 6.5 and later on Lenovo ThinkPad L570
To:     Linux regressions mailing list <regressions@lists.linux.dev>
Cc:     Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Jaak Ristioja <jaak@ristioja.ee>,
        Javier Martinez Canillas <javierm@redhat.com>,
        Linux DRI Development <dri-devel@lists.freedesktop.org>,
        David Airlie <airlied@gmail.com>,
        Daniel Vetter <daniel@ffwll.ch>,
        Thomas Zimmermann <tzimmermann@suse.de>,
        Bagas Sanjaya <bagasdotme@gmail.com>
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On Fri, Oct 20, 2023 at 5:35=E2=80=AFPM Linux regression tracking (Thorsten
Leemhuis) <regressions@leemhuis.info> wrote:
>
> On 09.10.23 10:54, Huacai Chen wrote:
> > On Mon, Oct 9, 2023 at 4:45=E2=80=AFPM Bagas Sanjaya <bagasdotme@gmail.=
com> wrote:
> >> On Mon, Oct 09, 2023 at 09:27:02AM +0800, Huacai Chen wrote:
> >>> On Tue, Sep 26, 2023 at 10:31=E2=80=AFPM Huacai Chen <chenhuacai@kern=
el.org> wrote:
> >>>> On Tue, Sep 26, 2023 at 7:15=E2=80=AFPM Linux regression tracking (T=
horsten
> >>>> Leemhuis) <regressions@leemhuis.info> 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 bl=
ank
> >>>>>> screen after boot until the display manager starts... if it does s=
tart
> >>>>>> at all. Using the nomodeset kernel parameter seems to be a workaro=
und.
> >>>>>>
> >>>>>> I've bisected this to commit 60aebc9559492cea6a9625f514a8041717e3a=
2e4
> >>>>>> ("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 missi=
ng
> >>>>> something.
> >>>>>
> >>>>> Huacai Chen, did you maybe miss this report? The problem is apparen=
tly
> >>>>> 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 con=
fig 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: Mov=
e
> >>> 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
> >
> >