Re: [PATCH 8/9] drm/i915/wm: Include ddb_y in skl_print_wm_changes() on pre-icl

Jani Nikula
2026-03-19T13:44:39Z

On Thu, 19 Mar 2026, Ville Syrjala <ville.syrjala@linux.intel.com> wrote:
> From: Ville Syrjälä <ville.syrjala@linux.intel.com>
>
> Pre-icl doesn't use a separate hardware plane for Y scanout,
> and instead it's all handled magially by the hardware. We

*magically

> do still need to allocate DDB space for the Y color plane
> though (PLANE_NV12_BUF_CFG). Include that information in the
> debugs so that we know where it ended up.
>
> On icl+ the equivalent information is dumped as the hardware
> Y plane's normal ddb allocation.
>
> Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
> ---
> drivers/gpu/drm/i915/display/skl_watermark.c | 11 +++++++++--
> 1 file changed, 9 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/display/skl_watermark.c b/drivers/gpu/drm/i915/display/skl_watermark.c
> index 8687026935e9..345767349988 100644
> --- a/drivers/gpu/drm/i915/display/skl_watermark.c
> +++ b/drivers/gpu/drm/i915/display/skl_watermark.c
> @@ -2735,10 +2735,17 @@ skl_print_wm_changes(struct intel_atomic_state *state)
> old = &old_crtc_state->wm.skl.plane_ddb[plane_id];
> new = &new_crtc_state->wm.skl.plane_ddb[plane_id];
>
> - if (skl_ddb_entry_equal(old, new))
> + if (!skl_ddb_entry_equal(old, new))
> + skl_print_plane_ddb_changes(plane, old, new, " ddb");

Superfluous whitespace in " ddb"?

Reviewed-by: Jani Nikula <jani.nikula@intel.com>

> +
> + if (DISPLAY_VER(display) >= 11)
> continue;
>
> - skl_print_plane_ddb_changes(plane, old, new, "ddb");
> + old = &old_crtc_state->wm.skl.plane_ddb_y[plane_id];
> + new = &new_crtc_state->wm.skl.plane_ddb_y[plane_id];
> +
> + if (!skl_ddb_entry_equal(old, new))
> + skl_print_plane_ddb_changes(plane, old, new, "ddb_y");
> }
>
> for_each_intel_plane_on_crtc(display->drm, crtc, plane) {

--
Jani Nikula, Intel