[Intel-gfx] [PATCH] drm/i915/dsc: Fix pic_width readout

[Borah, Chaitanya Kumar]

Hello Suraj,

> -----Original Message-----
> From: Kandpal, Suraj <suraj.kandpal at intel.com>
> Sent: Friday, September 8, 2023 10:26 AM
> To: intel-gfx at lists.freedesktop.org
> Cc: Shankar, Uma <uma.shankar at intel.com>; Manna, Animesh
> <animesh.manna at intel.com>; Borah, Chaitanya Kumar
> <chaitanya.kumar.borah at intel.com>; Kandpal, Suraj
> <suraj.kandpal at intel.com>
> Subject: [PATCH] drm/i915/dsc: Fix pic_width readout
> 
> pic_width when written into the PPS register is divided by the no.
> of vdsc instances first but the actual variable that we compare it to does not
> change i.e vdsc_cfg->pic_width hence when reading the register back for
> pic_width it needs to be multiplied by num_vdsc_instances rather than being
> divided.
> 
> Fixes: 8b70b5691704 ("drm/i915/vdsc: Fill the intel_dsc_get_pps_config
> function")
> Signed-off-by: Suraj Kandpal <suraj.kandpal at intel.com>
> ---
>  drivers/gpu/drm/i915/display/intel_vdsc.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_vdsc.c
> b/drivers/gpu/drm/i915/display/intel_vdsc.c
> index b24601d0b2c5..2d4279df9521 100644
> --- a/drivers/gpu/drm/i915/display/intel_vdsc.c
> +++ b/drivers/gpu/drm/i915/display/intel_vdsc.c
> @@ -883,7 +883,7 @@ static void intel_dsc_get_pps_config(struct
> intel_crtc_state *crtc_state)
>  	/* PPS_2 */
>  	intel_dsc_read_and_verify_pps_reg(crtc_state, 2, &pps_temp);
> 
> -	vdsc_cfg->pic_width = REG_FIELD_GET(DSC_PIC_WIDTH_MASK,
> pps_temp) / num_vdsc_instances;
> +	vdsc_cfg->pic_width = REG_FIELD_GET(DSC_PIC_WIDTH_MASK,
> pps_temp) *
> +num_vdsc_instances;

The patch need a rebase after

https://patchwork.freedesktop.org/patch/555835/

Change look good to me. Will wait for the rebase for the rb tag.

Regards

Chaitanya

>  	vdsc_cfg->pic_height = REG_FIELD_GET(DSC_PIC_HEIGHT_MASK,
> pps_temp);
> 
>  	/* PPS_3 */
> --
> 2.25.1