Re: drm/fbdev-dma: regression

From: Thomas Zimmermann
Date: Tue Nov 12 2024 - 03:11:43 EST


Hi


Am 11.11.24 um 20:06 schrieb Nuno Gonçalves:


On Mon, Nov 11, 2024, 14:37 Thomas Zimmermann <tzimmermann@xxxxxxx> wrote:

Hi


Am 11.11.24 um 14:42 schrieb Nuno Gonçalves:
> On Mon, Nov 11, 2024 at 1:22 PM Thomas Zimmermann
<tzimmermann@xxxxxxx> wrote:
>> The patch in question changes the whole memory management of the
>> affected code. It's also noteworthy that most of it has been
reworked
>> for the upcoming v6.12. Maybe this already fixed the problem.
Kernel
>> v6.11-rc7 added commit 5a498d4d06d6 ("drm/fbdev-dma: Only install
>> deferred I/O if necessary"), which possibly fixes the problem
as well.
>>
>> But there's no explicit fix for this problem and I have not
seen any
>> other related reports. Any further information is welcome.
> Issue was present since 5ab91447aa13b8b98bc11f5326f33500b0ee2c48 and
> tested until 6.12-rc3.
> Is there any suggestion on how to dig down?

Do you have a stack trace of this problem?


No. I need to build kernel with debug?

Isn't there an error message in the output of dmesg?

Or maybe can you save the whole output of dmesg after a crash and attach the file to an email?

In the original bug report, you mentioned that you often get an error. But not 'always'?

Do you have a reproducer for the problem? Such as a very simple program that triggers the bug.




Which hardware platform is affected?


ARM64 with ili9225 and display size 220, 176. It also
happens in another board with a different tinydrm driver and size 320,
240.

I meant, which board or CPU. ARM64/Aarch64 is really just a very broad term describing the system.

Best regards
Thomas


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Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
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