Re: [PATCH 0/2] Make HDMI state helpers handle odd max bpc requests

[Maxime Ripard]

Hi,

On Mon, Jun 08, 2026 at 01:19:06PM +0200, Nicolas Frattaroli wrote:
> With the "max bpc" KMS connector property, userspace can arbitrarily
> restrict the upper end of the bits-per-component range. This is fine and
> good, except the HDMI state helpers never considered that max_bpc could
> be influenced by a userspace setting, so assumed it'll always be an even
> value from the HDMI standards.
> 
> This, unfortunately, is not the world we live in anymore. Patch 1
> corrects sink_supports_format_bpc to return false on BPCs outside of
> what HDMI allows. Patch 2 then corrects handling of odd-numbered max
> bpcs by rounding the loop start value down to an even number instead. It
> also adds a KUnit test to make sure nobody breaks this again in the
> future.
> 
> Signed-off-by: Nicolas Frattaroli <nicolas.frattaroli@xxxxxxxxxxxxx>

Do you have a bit more details on the world you live in? :)

In particular, why would erroring out on setting an odd value in
atomic_set_property not work?

Maxime

Attachment: signature.asc
Description: PGP signature