WARNING: CPU: 0 PID: 8 at drivers/video/fbdev/core/fbmem.c:467 unregister_framebuffer+0x45/0x160

[V, Narasimhan]

[AMD Official Use Only - AMD Internal Distribution Only]

Hi,


________________________________________
From: Helge Deller <deller at gmx.de>
Sent: Tuesday, September 3, 2024 01:48 AM
To: V, Narasimhan; Thomas Zimmermann
Cc: Linux Next Mailing List; Daniel Vetter; linux-fbdev at vger.kernel.org; dri-devel at lists.freedesktop.org; open list; linux at weissschuh.net; Borislav Petkov
Subject: Re: WARNING: CPU: 0 PID: 8 at drivers/video/fbdev/core/fbmem.c:467 unregister_framebuffer+0x45/0x160

>On 9/2/24 20:56, V, Narasimhan wrote:
>> From: Thomas Zimmermann <tzimmermann at suse.de>
>>>>> Seeing the following warning and bug on boot with linux-next-20240829
>>>>>
>>>>> WARNING: CPU: 0 PID: 8 at drivers/video/fbdev/core/fbmem.c:467 unregister_framebuffer+0x45/0x160
>>>>> BUG: kernel NULL pointer dereference, address: 0000000000000000
>>
>>> Does it work if you revert one of these commits?
>>
>>>    c2fe0480cd77 ("fbdev/efifb: Use devm_register_framebuffer()")
>>
>>
>> Reverting this commit fixes the issue.

> Good.

>>> For the latter, there might be a fix at
>>
>>> https://patchwork.freedesktop.org/patch/611902/?series=138008&rev=1

> Current fbdev git tree and for-next series have this newer patch already.
> I expect that the issue is already resolved with there, but it would
> be good if you could test.

> Helge

The patch seems to be already into linux-next tree and the issue is no more seen with today's linux-next build.

--
Regards
Narasimhan V