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

[Huacai Chen]

Hi, Jaak,

On Wed, Nov 1, 2023 at 7:52 PM Jaak Ristioja <jaak@xxxxxxxxxxx> wrote:
>
> On 31.10.23 14:17, Huacai Chen wrote:
> > Hi, Jaak and Evan,
> >
> > On Sun, Oct 29, 2023 at 9:42 AM Huacai Chen <chenhuacai@xxxxxxxxxx> wrote:
> >>
> >> On Sat, Oct 28, 2023 at 7:06 PM Jaak Ristioja <jaak@xxxxxxxxxxx> wrote:
> >>>
> >>> On 26.10.23 03:58, Huacai Chen wrote:
> >>>> Hi, Jaak,
> >>>>
> >>>> On Thu, Oct 26, 2023 at 2:49 AM Jaak Ristioja <jaak@xxxxxxxxxxx> wrote:
> >>>>>
> >>>>> On 25.10.23 16:23, Huacai Chen wrote:
> >>>>>> On Wed, Oct 25, 2023 at 6:08 PM Thorsten Leemhuis
> >>>>>> <regressions@xxxxxxxxxxxxx> wrote:
> >>>>>>>
> >>>>>>> Javier, Dave, Sima,
> >>>>>>>
> >>>>>>> On 23.10.23 00:54, Evan Preston wrote:
> >>>>>>>> On 2023-10-20 Fri 05:48pm, Huacai Chen wrote:
> >>>>>>>>> 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").
> >>>>>>>>>>>>>>>
> >>>>>>>>>>>>> As confirmed by Jaak, disabling DRM_SIMPLEDRM makes things work fine
> >>>>>>>>>>>>> again. So I guess the reason:
> >>>>>>>>>>
> >>>>>>>>>> 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.
> >>>>>>>
> >>>>>>> Side note: Huacai, have you tried working with Jaak to get down to the
> >>>>>>> real problem? Evan, might you be able to help out here?
> >>>>>> No, Jaak has no response after he 'fixed' his problem by disabling SIMPLEDRM.
> >>>>>>
> >>>>>
> >>>>> I'm sorry, what was it exactly you want me to do? Please be mindful that
> >>>>> I'm not familiar with the internals of the Linux kernel and DRI, and it
> >>>>> might sometimes take weeks before I have time to work and respond on this.
> >>>> It doesn't matter. I hope you can do some experiments to investigate
> >>>> deeper. The first experiment you can do is enabling SIMPLEFB (i.e.
> >>>> CONFIG_FB_SIMPLE) instead of SIMPLEDRM (CONFIG_DRM_SIMPLEDRM) to see
> >>>> whether there is also a blank screen. If no blank screen, that
> >>>> probably means SIMPLEDRM has a bug, if still blank screen, that means
> >>>> the firmware may pass wrong screen information.
> >>>
> >>> Testing with 6.5.9 I get a blank screen with CONFIG_DRM_SIMPLEDRM=y and
> >>> get no blank screen with CONFIG_FB_SIMPLE=y and CONFIG_DRM_SIMPLEDRM unset.
> >> CONFIG_FB_SIMPLE and  CONFIG_DRM_SIMPLEDRM use the same device created
> >> by sysfb_init(). Since FB_SIMPLE works fine, I think the real problem
> >> is that DRM_SIMPLEDRM has a bug. The next step is to enable
> >> CONFIG_DRM_SIMPLEDRM and trace its initialization. In detail, adding
> >> some printk() in simpledrm_probe() and its sub-routines to see where
> >> the driver fails. The output of these printk() can be seen by the
> >> 'dmesg' command after boot.
> > I need your help. I tried with my laptop (ThinkPad E490, Intel Core
> > i3-8145U, UHD Graphics 620) but I can't reproduce your problem. So
> > please patch your 6.5.x kernel with this temporary patch [1], then
> > build a "bad kernel" with SIMPLEDRM enabled. And after booting your
> > machine with this "bad kernel", please give me the dmesg output. Thank
> > you very much.
> >
> > [1] http://ddns.miaomiaomiao.top:9000/download/kernel/patch-6.5.9
>
> I'm unable to download it. Can you please send it by e-mail?
I'm sorry, please download from attachment.

Huacai

>
> Jaak
>
> >
> >
> > Huacai
> >
> >>
> >> Huacai
> >>
> >>>
> >>> Jaak
> >>>
> >>>>
> >>>> Huacai
> >>>>
> >>>>>
> >>>>> Jaak
> >>>>>
> >>>>>>>
> >>>>>>> But I write this mail for a different reason:
> >>>>>>>
> >>>>>>>> I am having the same issue on a Lenovo Thinkpad P70 (Intel
> >>>>>>>> Corporation HD Graphics 530 (rev 06), Intel(R) Core(TM) i7-6700HQ).
> >>>>>>>> Upgrading from Linux 6.4.12 to 6.5 and later results in only a blank
> >>>>>>>> screen after boot and a rapidly flashing device-access-status
> >>>>>>>> indicator.
> >>>>>>>
> >>>>>>> This additional report makes me wonder if we should revert the culprit
> >>>>>>> (60aebc9559492c ("drivers/firmware: Move sysfb_init() from
> >>>>>>> device_initcall to subsys_initcall_sync") [v6.5-rc1]). But I guess that
> >>>>>>> might lead to regressions for some users? But the patch description says
> >>>>>>> that this is not a common configuration, so can we maybe get away with that?
> >>>>>>    From my point of view, this is not a regression, 60aebc9559492c
> >>>>>> doesn't cause a problem, but exposes a problem. So we need to fix the
> >>>>>> real problem (SIMPLEDRM has a blank screen on some conditions). This
> >>>>>> needs Jaak or Evan's help.
> >>>>>>
> >>>>>> 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.
> >>>>>>>
> >>>>>>>>>>>>> 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
> >>>>>>>>>>>
> >>>>>>>>>>>
> >>>>>>>>
> >>>>>>>>
> >>>>>
> >>>
>

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