drm: Add a debug node for vblank state.

Signed-off-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Dave Airlie <airlied@linux.ie>

3 files changed, 73 insertions, 0 deletions

diff --git a/drivers/gpu/drm/drm_irq.c b/drivers/gpu/drm/drm_irq.c
index 1608f8dbfda0..724e505873cf 100644
--- a/drivers/gpu/drm/drm_irq.c
+++ b/drivers/gpu/drm/drm_irq.c
@@ -116,6 +116,9 @@ void drm_vblank_cleanup(struct drm_device *dev)
                  dev->num_crtcs, DRM_MEM_DRIVER);
         drm_free(dev->last_vblank, sizeof(*dev->last_vblank) * dev->num_crtcs,
                  DRM_MEM_DRIVER);
+        drm_free(dev->last_vblank_wait,
+                 sizeof(*dev->last_vblank_wait) * dev->num_crtcs,
+                 DRM_MEM_DRIVER);
         drm_free(dev->vblank_inmodeset, sizeof(*dev->vblank_inmodeset) *
                  dev->num_crtcs, DRM_MEM_DRIVER);
 
@@ -161,6 +164,11 @@ int drm_vblank_init(struct drm_device *dev, int num_crtcs)
         if (!dev->last_vblank)
                 goto err;
 
+        dev->last_vblank_wait = drm_calloc(num_crtcs, sizeof(u32),
+                                           DRM_MEM_DRIVER);
+        if (!dev->last_vblank_wait)
+                goto err;
+
         dev->vblank_inmodeset = drm_calloc(num_crtcs, sizeof(int),
                                          DRM_MEM_DRIVER);
         if (!dev->vblank_inmodeset)
@@ -642,6 +650,7 @@ int drm_wait_vblank(struct drm_device *dev, void *data,
         } else {
                 DRM_DEBUG("waiting on vblank count %d, crtc %d\n",
                           vblwait->request.sequence, crtc);
+                dev->last_vblank_wait[crtc] = vblwait->request.sequence;
                 DRM_WAIT_ON(ret, dev->vbl_queue[crtc], 3 * DRM_HZ,
                             ((drm_vblank_count(dev, crtc)
                               - vblwait->request.sequence) <= (1 << 23)));
diff --git a/drivers/gpu/drm/drm_proc.c b/drivers/gpu/drm/drm_proc.c
index 7dbaa1a19ea4..8df849f66830 100644
--- a/drivers/gpu/drm/drm_proc.c
+++ b/drivers/gpu/drm/drm_proc.c
@@ -49,6 +49,8 @@ static int drm_queues_info(char *buf, char **start, off_t offset,
                            int request, int *eof, void *data);
 static int drm_bufs_info(char *buf, char **start, off_t offset,
                          int request, int *eof, void *data);
+static int drm_vblank_info(char *buf, char **start, off_t offset,
+                           int request, int *eof, void *data);
 static int drm_gem_name_info(char *buf, char **start, off_t offset,
                              int request, int *eof, void *data);
 static int drm_gem_object_info(char *buf, char **start, off_t offset,
@@ -72,6 +74,7 @@ static struct drm_proc_list {
         {"clients", drm_clients_info, 0},
         {"queues", drm_queues_info, 0},
         {"bufs", drm_bufs_info, 0},
+        {"vblank", drm_vblank_info, 0},
         {"gem_names", drm_gem_name_info, DRIVER_GEM},
         {"gem_objects", drm_gem_object_info, DRIVER_GEM},
 #if DRM_DEBUG_CODE
@@ -458,6 +461,66 @@ static int drm_bufs_info(char *buf, char **start, off_t offset, int request,
 }
 
 /**
+ * Called when "/proc/dri/.../vblank" is read.
+ *
+ * \param buf output buffer.
+ * \param start start of output data.
+ * \param offset requested start offset.
+ * \param request requested number of bytes.
+ * \param eof whether there is no more data to return.
+ * \param data private data.
+ * \return number of written bytes.
+ */
+static int drm__vblank_info(char *buf, char **start, off_t offset, int request,
+                          int *eof, void *data)
+{
+        struct drm_minor *minor = (struct drm_minor *) data;
+        struct drm_device *dev = minor->dev;
+        int len = 0;
+        int crtc;
+
+        if (offset > DRM_PROC_LIMIT) {
+                *eof = 1;
+                return 0;
+        }
+
+        *start = &buf[offset];
+        *eof = 0;
+
+        for (crtc = 0; crtc < dev->num_crtcs; crtc++) {
+                DRM_PROC_PRINT("CRTC %d enable:     %d\n",
+                               crtc, atomic_read(&dev->vblank_refcount[crtc]));
+                DRM_PROC_PRINT("CRTC %d counter:    %d\n",
+                               crtc, drm_vblank_count(dev, crtc));
+                DRM_PROC_PRINT("CRTC %d last wait:  %d\n",
+                               crtc, dev->last_vblank_wait[crtc]);
+                DRM_PROC_PRINT("CRTC %d in modeset: %d\n",
+                               crtc, dev->vblank_inmodeset[crtc]);
+        }
+
+        if (len > request + offset)
+                return request;
+        *eof = 1;
+        return len - offset;
+}
+
+/**
+ * Simply calls _vblank_info() while holding the drm_device::struct_mutex lock.
+ */
+static int drm_vblank_info(char *buf, char **start, off_t offset, int request,
+                         int *eof, void *data)
+{
+        struct drm_minor *minor = (struct drm_minor *) data;
+        struct drm_device *dev = minor->dev;
+        int ret;
+
+        mutex_lock(&dev->struct_mutex);
+        ret = drm__vblank_info(buf, start, offset, request, eof, data);
+        mutex_unlock(&dev->struct_mutex);
+        return ret;
+}
+
+/**
  * Called when "/proc/dri/.../clients" is read.
  *
  * \param buf output buffer.
diff --git a/include/drm/drmP.h b/include/drm/drmP.h
index 7802c80f2b23..afb7858c068d 100644
--- a/include/drm/drmP.h
+++ b/include/drm/drmP.h
@@ -911,6 +911,7 @@ struct drm_device {
         int *vblank_enabled;            /* so we don't call enable more than
                                            once per disable */
         int *vblank_inmodeset;          /* Display driver is setting mode */
+        u32 *last_vblank_wait;          /* Last vblank seqno waited per CRTC */
         struct timer_list vblank_disable_timer;
 
         u32 max_vblank_count;           /**< size of vblank counter register */