On 2026. július 11., szombat 21:35:07 közép-európai nyári idő Lionso Alejandro
Pacheco Vacacela wrote:
> Hi,
>
> I independently hit this regression on a desktop Kaveri system and can
> confirm this patch fixes it:
>
> - AMD A10-7850K (Kaveri, DCE 8.1), MSI A68HM-E33, VGA monitor on the
> onboard output (NUTMEG DP-to-VGA bridge)
> - Debian kernel 7.1.3 (amdgpu.cik_support=1): VGA monitor receives no
> signal from KMS takeover on; dmesg shows
> "[drm] enabling link 2 failed: 15" (DC_FAIL_DP_LINK_TRAINING).
> - Applying just this patch (1/2) on top of v7.1.3 restores VGA output
> with DC enabled: the link trains, the CRTC comes up at 1360x768@60,
> and the fix survived three consecutive reboots.
>
> Tested-by: Lionso Alejandro Pacheco Vacacela <[email protected]>
Thank you for the testing!
I would appreciate if you could verify that the second patch also works well.
>
> Two notes:
>
> 1. The Fixes: tag references b74322eea36b, but that hash does not exist
> in mainline — it looks like an amd-staging-internal id. In Linus'
> tree the offending commit is:
>
> a62346043a89 ("drm/amd/display: Fix coding style issue")
>
> It would be good to correct this before the patch is pushed so the
> stable tooling can resolve the dependency.
As far as I remember the regression hasn't made it upstream yet when I made
the fix, so the hash didn't exist in Linus's tree yet.
>
> 2. Since the offending commit shipped in v7.1, could this be annotated
> Cc: [email protected] # 7.1.x (or nominated for 7.1.y once it
> lands in mainline)? Every Kaveri/Kabini/Mullins system with a VGA
> monitor loses display output on release kernels.
Agreed. Alex can you please backport this to 7.1?
Thanks & best regards,
Timur
