drm/i915: Move the min/max scanline sanity check into intel_vblank_evade()

There isn't really any reason to make the caller suffer through
checking the vblank evasion min/max scanlines. If we somehow
ended up with bogus values (which really shouldn't happen)
then just skip the actual vblank evasion loop but otherwise
plow ahead as normal.

The only "real" change is that we now get+put a vblank reference
even if the min/max values are bogus, previously we skipped
directly to the end.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231213102519.13500-7-ville.syrjala@linux.intel.com
Reviewed-by: Uma Shankar <uma.shankar@intel.com>

diff --git a/drivers/gpu/drm/i915/display/intel_crtc.c b/drivers/gpu/drm/i915/display/intel_crtc.c
index 26a07b2..11a6a4b 100644 (file)
--- a/drivers/gpu/drm/i915/display/intel_crtc.c
+++ b/drivers/gpu/drm/i915/display/intel_crtc.c
@@ -544,6 +544,9 @@ static int intel_vblank_evade(struct intel_vblank_evade_ctx *evade)
        DEFINE_WAIT(wait);
        int scanline;
 
+       if (evade->min <= 0 || evade->max <= 0)
+               return 0;
+
        for (;;) {
                /*
                 * prepare_to_wait() has a memory barrier, which guarantees
@@ -633,8 +636,6 @@ void intel_pipe_update_start(struct intel_atomic_state *state,
                intel_crtc_vblank_work_init(new_crtc_state);
 
        intel_vblank_evade_init(old_crtc_state, new_crtc_state, &evade);
-       if (evade.min <= 0 || evade.max <= 0)
-               goto irq_disable;
 
        if (drm_WARN_ON(&dev_priv->drm, drm_crtc_vblank_get(&crtc->base)))
                goto irq_disable;