Re: [PATCH 0/3] drm/client: Fix display-mode selection

[Maxime Ripard <maxime@cerno.tech>]

[-- Attachment #1: Type: text/plain, Size: 1310 bytes --]

On Wed, May 11, 2022 at 08:31:22PM +0200, Thomas Zimmermann wrote:
> Pick user-defined display mode in DRM clients if the mode has been
> validated by the driver. Otherwise pick a preferred display mode.
> 
> Booting the kernel with video=<mode> and giving an unsupported display
> mode can easily turn the display unusable. This is best tested by
> booting simpledrm with a display mode that does not use the firmware
> framebuffer's resolution. While simpledrm filter's out the mode as
> invalid, the DRM client still picks it and the console won't show up.
> 
> Several factors contribute to this problem.
> 
>  * The connector invalidates the user-defined display mode, but never
>    tells the user about it.
>  * The DRM client doesn't look for user-defined display modes, but for
>    modes that are similar.
>  * If no similar mode can be found, the client adds the invalid display
>    mode back to the connector's mode list for use.
> 
> Each of the patches in this patchset addresses one of these problems.
> Overall the DRM client has no business in display-mode detection and
> should only pick one of the modes that has been detected and validated 
> by the connector.

That's awesome, thanks!

For the series,
Reviewed-by: Maxime Ripard <maxime@cerno.tech>

Maxime

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 228 bytes --]