Hi
Am 04.10.24 um 12:01 schrieb Ville Syrjälä:
On Fri, Oct 04, 2024 at 11:17:02AM +0200, Thomas Zimmermann wrote:
Hi
Am 02.10.24 um 18:15 schrieb Luck, Tony:
Thanks for the bug report. Can you provide the output of 'sudo lspci
-vvv' for the graphics device?
Thomas,
Sure. Here's the output (run on the v6.11.0 kernel)
Thanks. It doesn't look much different from other systems. IRQ is also
assigned.
Attached is a patch that fixes a possible off-by-one error in the
register settings. This would affect the bug you're reporting. If
possible, please apply the patch to your 6.12-rc1, test and report the
result.
Didn't one of these weird variants have some bug where the
CRTC startadd was not working? Is this one of those?
That to me sounds like maybe linecomp has internally been
tied to be always active somehow. Perhaps that would
also prevent it from generating the interrupt...
Impressive debugging skills! The broken chip has vendor id 0x0522
according to commit 21e74bf99596 ("drm/mgag200: Store HW_BUG_NO_STARTADD
flag in device info"). And that's the same type the Tony reported. [1]
I'm just not sure if it's worth special casing the chip again or simply
revert vblank irqs.
Best regards
Thomas
[1] https://admin.pci-ids.ucw.cz/read/PC/102b/0522
Anyways, sounds like someone should just double check whether
the status bit ever get asserted or not. If yes, then the
problem must be with interrupt delivery, otherwise the
problem is that the internal interrupt is never even
generated. In the latter case you could try using the
vsync interrupt instead.
--
--
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Frankenstrasse 146, 90461 Nuernberg, Germany
GF: Ivo Totev, Andrew Myers, Andrew McDonald, Boudien Moerman
HRB 36809 (AG Nuernberg)
