[PATCH] drm/mgag200: Force 32 bpp on the console

[Jocelyn Falempe]

On 15/09/2022 17:03, Thomas Zimmermann wrote:
> G200ER does not seem to support 24 bpp, so force the console to
> use 32 bpp. The problem was introduced, when commit 73f54d5d9682
> ("drm/mgag200: Remove special case for G200SE with <2 MiB") changed
> the preferred color depth from 32 bit to 24 bit.
> 
> A setting of 24 is the correct color depth, but G200ER doesn't seem
> to be able to use the respective RGB888 color format. Using 24-bit
> color with forced 32 bpp works around the problem.

Thanks for the patch.
At least on my G200EW, 24 bpp is working well. So maybe only the G200ER 
is affected.
I think it may have a performance penalty, I will try to measure it.

Reviewed-by: Jocelyn Falempe <jfalempe at redhat.com>

-- 

Jocelyn

> 
> Reported-by: Wang Yugui <wangyugui at e16-tech.com>
> Signed-off-by: Thomas Zimmermann <tzimmermann at suse.de>
> Tested-by: Wang Yugui <wangyugui at e16-tech.com>
> Fixes: 73f54d5d9682 ("drm/mgag200: Remove special case for G200SE with <2 MiB")
> Cc: Thomas Zimmermann <tzimmermann at suse.de>
> Cc: Jocelyn Falempe <jfalempe at redhat.com>
> Cc: Dave Airlie <airlied at redhat.com>
> Cc: dri-devel at lists.freedesktop.org
> ---
>   drivers/gpu/drm/mgag200/mgag200_drv.c | 6 +++++-
>   1 file changed, 5 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/mgag200/mgag200_drv.c b/drivers/gpu/drm/mgag200/mgag200_drv.c
> index 251a1bb648cc..a222bf76804f 100644
> --- a/drivers/gpu/drm/mgag200/mgag200_drv.c
> +++ b/drivers/gpu/drm/mgag200/mgag200_drv.c
> @@ -262,7 +262,11 @@ mgag200_pci_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
>   	if (ret)
>   		return ret;
>   
> -	drm_fbdev_generic_setup(dev, 0);
> +	/*
> +	 * FIXME: A 24-bit color depth does not work with 24 bpp on
> +	 * G200ER. Force 32 bpp.
> +	 */
> +	drm_fbdev_generic_setup(dev, 32);
>   
>   	return 0;
>   }