On Wed, 10 Jun 2026, Michał Grzelak <[email protected]> wrote:
> First clause of CASF check is independent of any loop iteration and
> causes intel_allocate_scaler() to fail when satisfied. Check it before
> entering the loop.
>
> Cc: Nemesa Garg <[email protected]>
> Cc: Ville Syrjälä <[email protected]>
> Signed-off-by: Michał Grzelak <[email protected]>
> ---
> drivers/gpu/drm/i915/display/skl_scaler.c | 6 ++++--
> 1 file changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/display/skl_scaler.c
> b/drivers/gpu/drm/i915/display/skl_scaler.c
> index f2216a9ea3f8..59a5a3cd3e6a 100644
> --- a/drivers/gpu/drm/i915/display/skl_scaler.c
> +++ b/drivers/gpu/drm/i915/display/skl_scaler.c
> @@ -339,12 +339,14 @@ static int intel_allocate_scaler(struct
> intel_crtc_scaler_state *scaler_state,
> struct intel_display *display = to_intel_display(crtc);
> int scaler_id;
>
> + if (casf_scaler && !HAS_CASF(display))
> + return -1;
Using -1 as magic error return value is one of my pet peeves.
-1 == -EPERM, and that's hardly the case here.
I know the function returns -1 elsewhere, both should be fixed. -EINVAL
is better.
BR,
Jani.
> +
> for (scaler_id = 0; scaler_id < crtc->num_scalers; scaler_id++) {
> if (scaler_state->scalers[scaler_id].in_use)
> continue;
>
> - if ((casf_scaler && !HAS_CASF(display)) ||
> - (casf_scaler && scaler_id != 1))
> + if (casf_scaler && scaler_id != 1)
> continue;
>
> scaler_state->scalers[scaler_id].in_use = true;
--
Jani Nikula, Intel
