On Thu, 07 Aug 2025, Ankit Nautiyal <ankit.k.nauti...@intel.com> wrote: > Add a drm_WARN_ON() in intel_crtc_init() to catch cases where > crtc->num_scalers exceeds the expected SKL_NUM_SCALERS limit. > > This condition should not occur, as the number of scalers per pipe does not > exceed two for current platforms, making SKL_NUM_SCALERS (2) a safer upper > limit. However, if a platform ever gains more scalers per pipe than > SKL_NUM_SCALERS, it could lead to issues when crtc->num_scalers is used to > iterate over scaler_state->scalers. > > To prevent this, warn and clamp the value to SKL_NUM_SCALERS. > > Suggested-by: Jani Nikula <jani.nik...@intel.com> > Signed-off-by: Ankit Nautiyal <ankit.k.nauti...@intel.com>
Reviewed-by: Jani Nikula <jani.nik...@intel.com> > --- > drivers/gpu/drm/i915/display/intel_crtc.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/drivers/gpu/drm/i915/display/intel_crtc.c > b/drivers/gpu/drm/i915/display/intel_crtc.c > index a187db6df2d3..e262e686dc2b 100644 > --- a/drivers/gpu/drm/i915/display/intel_crtc.c > +++ b/drivers/gpu/drm/i915/display/intel_crtc.c > @@ -317,6 +317,9 @@ int intel_crtc_init(struct intel_display *display, enum > pipe pipe) > crtc->pipe = pipe; > crtc->num_scalers = DISPLAY_RUNTIME_INFO(display)->num_scalers[pipe]; > > + if (drm_WARN_ON(display->drm, crtc->num_scalers > SKL_NUM_SCALERS)) > + crtc->num_scalers = SKL_NUM_SCALERS; > + > if (DISPLAY_VER(display) >= 9) > primary = skl_universal_plane_create(display, pipe, PLANE_1); > else -- Jani Nikula, Intel
