> -----Original Message-----
> From: Intel-gfx <intel-gfx-bounces@xxxxxxxxxxxxxxxxxxxxx> On Behalf Of Ville Syrjala
> Sent: Wednesday, November 23, 2022 8:57 PM
> To: intel-gfx@xxxxxxxxxxxxxxxxxxxxx
> Subject: [PATCH 10/13] drm/i915: Disable DSB usage specifically for LUTs
>
> From: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
>
> The DSB has problem loading the LUTs at the moment. Some of that is due to the
> palette anti collision logic, some due to what seem real hw issues. Disable it the
> whole thing locally in the color management code for now.
>
> Note that we currently have this weird situation where on
> adl+ we load parts of the LUT with DSB and parts with mmio.
> That is due to the fact that only some parts of the LUT code are using the DSB
> register write functions (ivb_load_lut_ext*()), while the rest is using pure mmio
> (bdw_load_lut_10()). So now we'll go back to pure mmio temporarily, until the DSB
> issues get fixed (at which point we should be going for pure DSB).
Yeah, we need to debug and analyze the failure with DSB. If needed,
we can raise a hardware sighting.
For now, let's keep it disabled:
Reviewed-by: Uma Shankar <uma.shankar@xxxxxxxxx>
> Signed-off-by: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
> ---
> drivers/gpu/drm/i915/display/intel_color.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_color.c
> b/drivers/gpu/drm/i915/display/intel_color.c
> index 2715f1b617e1..9978d21f1634 100644
> --- a/drivers/gpu/drm/i915/display/intel_color.c
> +++ b/drivers/gpu/drm/i915/display/intel_color.c
> @@ -1394,6 +1394,9 @@ void intel_color_prepare_commit(struct intel_crtc_state
> *crtc_state) {
> struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc);
>
> + /* FIXME DSB has issues loading LUTs, disable it for now */
> + return;
> +
> crtc_state->dsb = intel_dsb_prepare(crtc); }
>
> --
> 2.37.4
