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

Thomas Zimmermann <tzimmermann@xxxxxxx> · Tue, 20 Sep 2022 09:57:35 +0200

Hi

Am 15.09.22 um 16:41 schrieb Wang Yugui:
Hi,

Hi

Am 14.09.22 um 16:58 schrieb Wang Yugui:
[...]
24-bit works on my G200HE and G200 test machines. Maybe the G200ER has a bug.

When I try 16-bit depth, the display works, but is way too dark. No fiddling with the LUT tables fixes this. It's 90s hardware, so it should support 16-bit framebuffers well, but there's no obvious bug to be seen.

I guess, we could remove 16 and 24 bit support for now if nothing else helps.

maybe better if we revert 73f54d5d9682 (drm/mgag200: Remove special case
for G200SE with <2 MiB)

Could you please test the attached patch on the 6.0-rc3 kernel? It should force the driver to a correct color format if no kernel parameters are given.

This patch works well.

I have meanwhile added the patch to drm-misc-fixes. We want to add a 
workaround for your machine to the driver. Can you please send me the 
output of

  sudo dmidecode -s system-manufacturer

and

  sudo dmidecode -s system-product-name

Best regards
Thomas

test case detail:
   kernel parm video is not given
   server DELL/T620
   kernel is 6.0-rc5

Best Regards
Wang Yugui (wangyugui@xxxxxxxxxxxx)
2022/09/15

Best regards
Thomas

because there is no test result on device G200_SE

static unsigned int mgag200_preferred_depth(struct mga_device *mdev)
{
         if (IS_G200_SE(mdev) && mdev->vram_fb_available < (2048*1024))
                 return 16;
         else
                 return 32;
}

Best Regards
Wang Yugui (wangyugui@xxxxxxxxxxxx)
2022/09/14

-- Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Maxfeldstr. 5, 90409 Nürnberg, Germany
(HRB 36809, AG Nürnberg)
Gesch?ftsführer: Ivo Totev

--
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Maxfeldstr. 5, 90409 Nürnberg, Germany
(HRB 36809, AG Nürnberg)
Geschäftsführer: Ivo Totev
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