Re: [PATCH v7 1/5] drm: Define user readable error codes for atomic ioctl

["Murthy, Arun R" <arun.r.murthy@intel.com>]

On 21-01-2026 19:17, Xaver Hugl wrote:
>> +       DRM_MODE_ATOMIC_ASYNC_NOT_SUPP_PLANE,
> I don't think it makes sense to have an enum value for this, the
> per-plane support for async pageflips should be reported to the
> compositor in a way that doesn't require atomic tests. Once that's
> done, trying to do async flips with it is just invalid API usage.
Sure will remove this!
For getting to know if async flip is supported on a plane or not 
IN_FORMATS_ASYNC can be used.
>
>> +       DRM_MODE_ATOMIC_ASYNC_MODIFIER_NOT_SUPP,
> Same here, there's already a drm property for async-capable
> format+modifiers on each plane, so this falls under invalid API usage.
>
> One more thing I noticed for the failure codes: I think it would be
> better if INVALID_API_USAGE and unspecified errors would be split,
> with the latter being the default error code.
> Afaict with the current version the compositor would be told it's
> using the API wrong when it's just a normal test failure that the
> driver hasn't added a more specific error code for yet.
> INVALID_API_USAGE would then just be for actual "you should know
> better than to try this" cases, which should never happen in correct
> compositor operation.
Got it, all driver compatibility/not supported will go with proper error 
code and anything already known to compositor but still sends it wrongly 
will fall under INVALID_API_USAGE.
> Other than that, the API looks good to me. I'll put together a KWin
> implementation soon.

Thanks for the inputs and review.


Thanks and Regards,
Arun R Murthy
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