Empty IN_FORMATS in sun4i-drm

[Jernej Škrabec]

Hi!

Dne četrtek, 23. december 2021 ob 10:59:23 CET je Emmanuel Gil Peyrot 
napisal(a):
> On Tue, Dec 14, 2021 at 06:58:56PM +0100, Jernej Škrabec wrote:
> > Dne torek, 14. december 2021 ob 13:02:48 CET je Emmanuel Gil Peyrot 
> > napisal(a):
> > > Hi,
> > > 
> > > After updating Weston from 9f8561e9 to 07326040 (latest master), it
> > > fails to run on my PinePhone saying “format 0x34325258 not supported by
> > > output DSI-1” and then exiting.
> > > 
> > > This format is XR24, which would be extremely surprising not to be
> > > present, and drm_info[1] says it is present.  Looking into Weston’s
> > > code, I found that drm_plane_populate_formats()’s docstring says it uses
> > > “either the IN_FORMATS blob property (if available), or the plane's
> > > format list if not.”  Looking back at drm_info, I saw said IN_FORMATS
> > > blob being empty of formats (while the format list is fully populated):
> > > "IN_FORMATS" (immutable): blob = 32
> > > └───DRM_FORMAT_MOD_LINEAR (0x0)
> > 
> > Does this solve your issue? http://ix.io/3Ipo
> 
> Hi, yes it does, thanks!
> 
> Tested-by: Emmanuel Gil Peyrot <linkmauve at linkmauve.fr>

Thanks, but this issue is already in process of being fixed with a more general 
approach (this driver is not the only one with this type of issue).

Please look and comment at:
https://patchwork.kernel.org/project/dri-devel/cover/20211222090552.25972-1-jose.exposito89@gmail.com/

Best regards,
Jernej

> 
> > 
> > Best regards,
> > Jernej
> > 
> > > 
> > > This makes me think the kernel should populate IN_FORMATS with at least
> > > the same formats as the format list when supported, or stop advertising
> > > this property altogether.
> > > 
> > > Other compositors (such as phoc) still run file, probably because they
> > > use the format list exclusively, without consideration for modifiers.
> > > 
> > > Besides fixing this driver, would it make sense to also make Weston
> > > ignore an empty IN_FORMATS and fall back to the format list?
> > > 
> > > Thanks,
> > > 
> > > [1] https://github.com/ascent12/drm_info
> > > 
> > > -- 
> > > Emmanuel Gil Peyrot
> > > 
> > 
> 
> -- 
> Emmanuel Gil Peyrot
>