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?
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
