drm/i915: Only one open() allowed on pipe CRC result files
It doesn't really make sense to have two processes dequeueing the CRC
values at the same time. Forbid that usage.
Signed-off-by: Damien Lespiau <damien.lespiau@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
index 5137f8f..826ebce 100644
--- a/drivers/gpu/drm/i915/i915_debugfs.c
+++ b/drivers/gpu/drm/i915/i915_debugfs.c
@@ -1768,6 +1768,15 @@
static int i915_pipe_crc_open(struct inode *inode, struct file *filep)
{
+ struct pipe_crc_info *info = inode->i_private;
+ struct drm_i915_private *dev_priv = info->dev->dev_private;
+ struct intel_pipe_crc *pipe_crc = &dev_priv->pipe_crc[info->pipe];
+
+ if (!atomic_dec_and_test(&pipe_crc->available)) {
+ atomic_inc(&pipe_crc->available);
+ return -EBUSY; /* already open */
+ }
+
filep->private_data = inode->i_private;
return 0;
@@ -1775,6 +1784,12 @@
static int i915_pipe_crc_release(struct inode *inode, struct file *filep)
{
+ struct pipe_crc_info *info = inode->i_private;
+ struct drm_i915_private *dev_priv = info->dev->dev_private;
+ struct intel_pipe_crc *pipe_crc = &dev_priv->pipe_crc[info->pipe];
+
+ atomic_inc(&pipe_crc->available); /* release the device */
+
return 0;
}
@@ -2684,6 +2699,7 @@
for (i = 0; i < INTEL_INFO(dev)->num_pipes; i++) {
struct intel_pipe_crc *pipe_crc = &dev_priv->pipe_crc[i];
+ atomic_set(&pipe_crc->available, 1);
init_waitqueue_head(&pipe_crc->wq);
}
}