drm/i915: add more debug info for when atomic updates fail v3

I used these additional fields to track down the issue I saw on HSW.

v2: move debug fields into a substruct (Ville)
v3: clean up debug code more (Ville)

References: https://bugs.freedesktop.org/show_bug.cgi?id=91579
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>

diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index e9e5cfd..8760814 100644 (file)
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -565,8 +565,12 @@ struct intel_crtc {
 
        int scanline_offset;
 
-       unsigned start_vbl_count;
-       ktime_t start_vbl_time;
+       struct {
+               unsigned start_vbl_count;
+               ktime_t start_vbl_time;
+               int min_vbl, max_vbl;
+               int scanline_start;
+       } debug;
 
        struct intel_crtc_atomic_commit atomic;
 

diff --git a/drivers/gpu/drm/i915/intel_sprite.c b/drivers/gpu/drm/i915/intel_sprite.c
index 4d27243..7de121d 100644 (file)
--- a/drivers/gpu/drm/i915/intel_sprite.c
+++ b/drivers/gpu/drm/i915/intel_sprite.c
@@ -95,7 +95,6 @@ void intel_pipe_update_start(struct intel_crtc *crtc)
        max = vblank_start - 1;
 
        local_irq_disable();
-       crtc->start_vbl_count = 0;
 
        if (min <= 0 || max <= 0)
                return;
@@ -134,11 +133,15 @@ void intel_pipe_update_start(struct intel_crtc *crtc)
 
        drm_crtc_vblank_put(&crtc->base);
 
-       crtc->start_vbl_time = ktime_get();
-       crtc->start_vbl_count = dev->driver->get_vblank_counter(dev, pipe);
+       crtc->debug.min_vbl = min;
+       crtc->debug.max_vbl = max;
+       crtc->debug.scanline_start = scanline;
+       crtc->debug.start_vbl_time = ktime_get();
+       crtc->debug.start_vbl_count =
+               dev->driver->get_vblank_counter(dev, pipe);
 
        trace_i915_pipe_update_vblank_evaded(crtc, min, max,
-                                            crtc->start_vbl_count);
+                                            crtc->debug.start_vbl_count);
 }
 
 /**
@@ -154,6 +157,7 @@ void intel_pipe_update_end(struct intel_crtc *crtc)
 {
        struct drm_device *dev = crtc->base.dev;
        enum pipe pipe = crtc->pipe;
+       int scanline_end = intel_get_crtc_scanline(crtc);
        u32 end_vbl_count = dev->driver->get_vblank_counter(dev, pipe);
        ktime_t end_vbl_time = ktime_get();
 
@@ -161,10 +165,15 @@ void intel_pipe_update_end(struct intel_crtc *crtc)
 
        local_irq_enable();
 
-       if (crtc->start_vbl_count && crtc->start_vbl_count != end_vbl_count)
-               DRM_ERROR("Atomic update failure on pipe %c (start=%u end=%u) time %lld us\n",
-                         pipe_name(pipe), crtc->start_vbl_count, end_vbl_count,
-                         ktime_us_delta(end_vbl_time, crtc->start_vbl_time));
+       if (crtc->debug.start_vbl_count &&
+           crtc->debug.start_vbl_count != end_vbl_count) {
+               DRM_ERROR("Atomic update failure on pipe %c (start=%u end=%u) time %lld us, min %d, max %d, scanline start %d, end %d\n",
+                         pipe_name(pipe), crtc->debug.start_vbl_count,
+                         end_vbl_count,
+                         ktime_us_delta(end_vbl_time, crtc->debug.start_vbl_time),
+                         crtc->debug.min_vbl, crtc->debug.max_vbl,
+                         crtc->debug.scanline_start, scanline_end);
+       }
 }
 
 static void