@@ -74,6 +74,14 @@ int intel_usecs_to_scanlines(const struct drm_display_mode *adjusted_mode,
#define VBLANK_EVASION_TIME_US 100
#endif
+static inline bool scanline_in_vblank(struct intel_crtc *crtc,
+ int min, int max,
+ int *scanline)
+{
+ *scanline = intel_get_crtc_scanline(crtc);
+ return *scanline < min && *scanline > max;
+}
+
/**
* intel_pipe_update_start() - start update of a set of display registers
* @new_crtc_state: the new crtc state
@@ -91,12 +99,9 @@ void intel_pipe_update_start(const struct intel_crtc_state *new_crtc_state)
struct intel_crtc *crtc = to_intel_crtc(new_crtc_state->base.crtc);
struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
const struct drm_display_mode *adjusted_mode = &new_crtc_state->base.adjusted_mode;
- long timeout = msecs_to_jiffies_timeout(1);
int scanline, min, max, vblank_start;
- wait_queue_head_t *wq = drm_crtc_vblank_waitqueue(&crtc->base);
bool need_vlv_dsi_wa = (IS_VALLEYVIEW(dev_priv) || IS_CHERRYVIEW(dev_priv)) &&
intel_crtc_has_type(new_crtc_state, INTEL_OUTPUT_DSI);
- DEFINE_WAIT(wait);
vblank_start = adjusted_mode->crtc_vblank_start;
if (adjusted_mode->flags & DRM_MODE_FLAG_INTERLACE)
@@ -112,41 +117,46 @@ void intel_pipe_update_start(const struct intel_crtc_state *new_crtc_state)
if (min <= 0 || max <= 0)
return;
- if (WARN_ON(drm_crtc_vblank_get(&crtc->base)))
- return;
-
crtc->debug.min_vbl = min;
crtc->debug.max_vbl = max;
trace_i915_pipe_update_start(crtc);
- for (;;) {
- /*
- * prepare_to_wait() has a memory barrier, which guarantees
- * other CPUs can see the task state update by the time we
- * read the scanline.
- */
- prepare_to_wait(wq, &wait, TASK_UNINTERRUPTIBLE);
+ if (!scanline_in_vblank(crtc, min, max, &scanline)) {
+ wait_queue_head_t *wq = drm_crtc_vblank_waitqueue(&crtc->base);
+ long timeout = msecs_to_jiffies_timeout(1);
+ DEFINE_WAIT(wait);
- scanline = intel_get_crtc_scanline(crtc);
- if (scanline < min || scanline > max)
- break;
+ if (WARN_ON(drm_crtc_vblank_get(&crtc->base)))
+ goto skip_evade;
- if (timeout <= 0) {
- DRM_ERROR("Potential atomic update failure on pipe %c\n",
- pipe_name(crtc->pipe));
- break;
- }
+ for (;;) {
+ /*
+ * prepare_to_wait() has a memory barrier, which
+ * guarantees other CPUs can see the task state update
+ * by the time we read the scanline.
+ */
+ prepare_to_wait(wq, &wait, TASK_UNINTERRUPTIBLE);
- local_irq_enable();
+ if (scanline_in_vblank(crtc, min, max, &scanline))
+ break;
- timeout = schedule_timeout(timeout);
+ if (timeout <= 0) {
+ DRM_ERROR("Potential atomic update failure on pipe %c\n",
+ pipe_name(crtc->pipe));
+ break;
+ }
- local_irq_disable();
- }
+ local_irq_enable();
- finish_wait(wq, &wait);
+ timeout = schedule_timeout(timeout);
- drm_crtc_vblank_put(&crtc->base);
+ local_irq_disable();
+ }
+
+ finish_wait(wq, &wait);
+
+ drm_crtc_vblank_put(&crtc->base);
+ }
/*
* On VLV/CHV DSI the scanline counter would appear to
@@ -166,6 +176,7 @@ void intel_pipe_update_start(const struct intel_crtc_state *new_crtc_state)
while (need_vlv_dsi_wa && scanline == vblank_start)
scanline = intel_get_crtc_scanline(crtc);
+skip_evade:
crtc->debug.scanline_start = scanline;
crtc->debug.start_vbl_time = ktime_get();
crtc->debug.start_vbl_count = intel_crtc_get_vblank_counter(crtc);