Re: mgag200 broken on kernel-6.0-rc3 on DELL/T620

[Wang Yugui <wangyugui@e16-tech.com>]

Hi,


> Hi
> 
> Am 13.09.22 um 17:15 schrieb Wang Yugui:
> [...]
> >>>
> >>> so I tried to revert patch of mgag200 driver in batch of 2 or 3, the I
> >>> noticed the patch 'Subject: drm/mgag200: Remove special case for G200SE
> >>> with <2 MiB' and then tried this dirty fix.
> >>
> >> Oh, great work! Thank you. From looking at the screenshot that you provided, it seems as if the 24-bit mode setting is broken. I'm not sure why the G200SE workaround applies to a G200ER, but we'll see.
> >
> > I tested 'preferred_depth = 32' too. it works on T630 too.
> >
> > so both 16 and 32 work, but 24 failed on DELL/T630.
> 
> I tried on my test machine with a 5.19 kernel and found that 32-bit and 24-bit pixels work, but 16-bit looks incorrect.
> 
> What are the results if you boot your kernel 5.19.3 with the parameter video=1024x768-24? This should enable 24-bit pixels.
> 
> How does video=1024x768-16 look with the 5.19 kernel?

test result here
kernel 5.19.3 & video=1024x768-24
	dell/T620/centos-8.5	broken
	dell/T630/centos-7.9	broken

kernel 5.19.3 & video=1024x768-32
	dell/T620/centos-8.5	OK
	dell/T630/centos-7.9	OK

Both DELL/T620 and DELL/T630 have the lastest BIOS/iDRAC installed.

Best Regards
Wang Yugui (wangyugui@e16-tech.com)
2022/09/14



> 
> Best regards
> Thomas
> 
> >
> > diff --git a/drivers/gpu/drm/mgag200/mgag200_mode.c
> > b/drivers/gpu/drm/mgag200/mgag200_mode.c
> > index 225cca2ed60e..563e3ab05fbc 100644
> > --- a/drivers/gpu/drm/mgag200/mgag200_mode.c
> > +++ b/drivers/gpu/drm/mgag200/mgag200_mode.c
> > @@ -1070,7 +1070,7 @@ int mgag200_modeset_init(struct mga_device *mdev, resource_size_t vram_available
> >
> >          dev->mode_config.max_width = MGAG200_MAX_FB_WIDTH;
> >          dev->mode_config.max_height = MGAG200_MAX_FB_HEIGHT;
> > -       dev->mode_config.preferred_depth = 24;
> > +       dev->mode_config.preferred_depth = 32;
> >          dev->mode_config.fb_base = mdev->vram_res->start;
> >          dev->mode_config.funcs = &mgag200_mode_config_funcs;
> >
> > Best Regards
> > Wang Yugui (wangyugui@e16-tech.com)
> > 2022/09/13
> >
> >
> > 
> -- Thomas Zimmermann
> Graphics Driver Developer
> SUSE Software Solutions Germany GmbH
> Maxfeldstr. 5, 90409 Nürnberg, Germany
> (HRB 36809, AG Nürnberg)
> Gesch?ftsführer: Ivo Totev