On Wed, Mar 09, 2022 at 06:49:44PM +0200, Ville Syrjala wrote: > From: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> > > If the mailbox returns an exceesively large SAGV block time let's just > reject it. This avoids having to worry about overflows when we add the > SAGV block time to the wm0 latency. > > We shall put the limit arbitrarily at U16_MAX. >65msec latency > doesn't really make sense to me in any case. > > Signed-off-by: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> Reviewed-by: Stanislav Lisovskiy <stanislav.lisovskiy@xxxxxxxxx> > --- > drivers/gpu/drm/i915/intel_pm.c | 6 ++++++ > 1 file changed, 6 insertions(+) > > diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c > index 36f5bccabf64..166246fa27e4 100644 > --- a/drivers/gpu/drm/i915/intel_pm.c > +++ b/drivers/gpu/drm/i915/intel_pm.c > @@ -3716,6 +3716,12 @@ static void intel_sagv_init(struct drm_i915_private *i915) > drm_dbg_kms(&i915->drm, "SAGV supported: %s, original SAGV block time: %u us\n", > str_yes_no(intel_has_sagv(i915)), i915->sagv_block_time_us); > > + /* avoid overflow when adding with wm0 latency/etc. */ > + if (drm_WARN(&i915->drm, i915->sagv_block_time_us > U16_MAX, > + "Excessive SAGV block time %u, ignoring\n", > + i915->sagv_block_time_us)) > + i915->sagv_block_time_us = 0; > + > if (!intel_has_sagv(i915)) > i915->sagv_block_time_us = 0; > } > -- > 2.34.1 >
