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

[Thorsten Leemhuis]

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?

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?

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
>>>>
>>>>
> 
>