Please use "drm/i915/dsc: " as the subject prefix.
On Wed, 31 Jan 2024, Manasi Navare <navaremanasi@xxxxxxxxxxxx> wrote:
> Patch (bd077259d0a9: drm/i915/vdsc: Add function to read any PPS register) defines
Please use the usual style to refer to commits:
Commit bd077259d0a9 ("drm/i915/vdsc: Add function to read any PPS register")
> a new macro to calculate the DSC PPS register addresses with PPS number as an
> input. This macro correctly calculates the addresses till PPS 11 since the
> addresses increment by 4. So in that case the following macro works correctly
> to give correct register address:
> _MMIO(_DSCA_PPS_0 + (pps) * 4)
>
> However after PPS 11, the register address for PPS 12 increments by 12 because
> of RC Buffer memory allocation in between. Because of this discontinuity
> in the address space, the macro calculates wrong addresses for PPS 12 - 16
> resulting into incorrect DSC PPS parameter value read/writes causing DSC
> corruption.
Thanks for catching and debugging this!
> This patch fixes it by correcting this macro to add the offset of 12 for
> PPS >=12.
Please just say "Fix it ...". Once committed, this is no longer a patch.
> Bug: https://gitlab.freedesktop.org/drm/intel/-/issues/10172
Closes: instead of Bug:.
> Fixes: bd077259d0a9 ("drm/i915/vdsc: Add function to read any PPS register")
> Cc: Suraj Kandpal <suraj.kandpal@xxxxxxxxx>
> Cc: Ankit Nautiyal <ankit.k.nautiyal@xxxxxxxxx>
> Cc: Animesh Manna <animesh.manna@xxxxxxxxx>
> Cc: Jani Nikula <jani.nikula@xxxxxxxxxxxxxxx>
> Cc: Sean Paul <sean@xxxxxxxxxx>
> Cc: Drew Davenport <ddavenport@xxxxxxxxxxxx>
> Signed-off-by: Manasi Navare <navaremanasi@xxxxxxxxxxxx>
> ---
> drivers/gpu/drm/i915/display/intel_vdsc_regs.h | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_vdsc_regs.h b/drivers/gpu/drm/i915/display/intel_vdsc_regs.h
> index 64f440fdc22b..db29660b74f3 100644
> --- a/drivers/gpu/drm/i915/display/intel_vdsc_regs.h
> +++ b/drivers/gpu/drm/i915/display/intel_vdsc_regs.h
> @@ -51,8 +51,8 @@
> #define DSCC_PICTURE_PARAMETER_SET_0 _MMIO(0x6BA00)
> #define _DSCA_PPS_0 0x6B200
> #define _DSCC_PPS_0 0x6BA00
> -#define DSCA_PPS(pps) _MMIO(_DSCA_PPS_0 + (pps) * 4)
> -#define DSCC_PPS(pps) _MMIO(_DSCC_PPS_0 + (pps) * 4)
> +#define DSCA_PPS(pps) ((pps < 12) ? _MMIO(_DSCA_PPS_0 + (pps) * 4):_MMIO(_DSCA_PPS_0 + (pps + 12) * 4))
> +#define DSCC_PPS(pps) ((pps < 12) ? _MMIO(_DSCC_PPS_0 + (pps) * 4):_MMIO(_DSCC_PPS_0 + (pps + 12) * 4))
There's no need to duplicate so much here, this could be just:
_MMIO(_DSCC_PPS_0 + ((pps) < 12 ? (pps) : (pps) + 12) * 4)
Also the macro arguments need to be wrapped in braces.
With the nitpicks fixed, LGTM.
BR,
Jani.
> #define _ICL_DSC0_PICTURE_PARAMETER_SET_0_PB 0x78270
> #define _ICL_DSC1_PICTURE_PARAMETER_SET_0_PB 0x78370
> #define _ICL_DSC0_PICTURE_PARAMETER_SET_0_PC 0x78470
--
Jani Nikula, Intel
