Merge tag 'drm-misc-next-2017-01-09' of git://anongit.freedesktop.org/git/drm-misc into drm-next

Back to regular -misc pulls with reasonable sizes:
- dma_fence error clarification (Chris)
- drm_crtc_from_index helper (Shawn), pile more patches on the m-l to roll
  this out to drivers
- mmu-less support for fbdev helpers from Benjamin
- piles of kerneldoc work
- some polish for crc support from Tomeu and Benjamin
- odd misc stuff all over

* tag 'drm-misc-next-2017-01-09' of git://anongit.freedesktop.org/git/drm-misc: (48 commits)
  dma-fence: Introduce drm_fence_set_error() helper
  dma-fence: Wrap querying the fence->status
  dma-fence: Clear fence->status during dma_fence_init()
  drm: fix compilations issues introduced by "drm: allow to use mmuless SoC"
  drm: Change the return type of the unload hook to void
  drm: add more document for drm_crtc_from_index()
  drm: remove useless parameters from drm_pick_cmdline_mode function
  drm: crc: Call wake_up_interruptible() each time there is a new CRC entry
  drm: allow to use mmuless SoC
  drm: compile drm_vm.c only when needed
  fbmem: add a default get_fb_unmapped_area function
  drm: crc: Wait for a frame before returning from open()
  drm: Move locking into drm_debugfs_crtc_crc_add
  drm/imx: imx-tve: Remove unused variable
  Revert "drm: nouveau: fix build when LEDS_CLASS=m"
  drm: Add kernel-doc for drm_crtc_commit_get/put
  drm/atomic: Fix outdated comment.
  drm: reference count event->completion
  gpu: drm: mgag200: mgag200_main:- Handle error from pci_iomap
  drm: Document deprecated load/unload hook
  ...

1 files changed, 26 insertions, 8 deletions

diff --git a/drivers/gpu/drm/drm_debugfs_crc.c b/drivers/gpu/drm/drm_debugfs_crc.c
index 00e771fb7df2..96891c4a6e23 100644
--- a/drivers/gpu/drm/drm_debugfs_crc.c
+++ b/drivers/gpu/drm/drm_debugfs_crc.c
@@ -125,6 +125,12 @@ static const struct file_operations drm_crtc_crc_control_fops = {
 	.write = crc_control_write
 };
 
+static int crtc_crc_data_count(struct drm_crtc_crc *crc)
+{
+	assert_spin_locked(&crc->lock);
+	return CIRC_CNT(crc->head, crc->tail, DRM_CRC_ENTRIES_NR);
+}
+
 static int crtc_crc_open(struct inode *inode, struct file *filep)
 {
 	struct drm_crtc *crtc = inode->i_private;
@@ -160,8 +166,19 @@ static int crtc_crc_open(struct inode *inode, struct file *filep)
 	crc->entries = entries;
 	crc->values_cnt = values_cnt;
 	crc->opened = true;
+
+	/*
+	 * Only return once we got a first frame, so userspace doesn't have to
+	 * guess when this particular piece of HW will be ready to start
+	 * generating CRCs.
+	 */
+	ret = wait_event_interruptible_lock_irq(crc->wq,
+						crtc_crc_data_count(crc),
+						crc->lock);
 	spin_unlock_irq(&crc->lock);
 
+	WARN_ON(ret);
+
 	return 0;
 
 err_disable:
@@ -189,12 +206,6 @@ static int crtc_crc_release(struct inode *inode, struct file *filep)
 	return 0;
 }
 
-static int crtc_crc_data_count(struct drm_crtc_crc *crc)
-{
-	assert_spin_locked(&crc->lock);
-	return CIRC_CNT(crc->head, crc->tail, DRM_CRC_ENTRIES_NR);
-}
-
 /*
  * 1 frame field of 10 chars plus a number of CRC fields of 10 chars each, space
  * separated, with a newline at the end and null-terminated.
@@ -325,16 +336,19 @@ int drm_crtc_add_crc_entry(struct drm_crtc *crtc, bool has_frame,
 	struct drm_crtc_crc_entry *entry;
 	int head, tail;
 
-	assert_spin_locked(&crc->lock);
+	spin_lock(&crc->lock);
 
 	/* Caller may not have noticed yet that userspace has stopped reading */
-	if (!crc->opened)
+	if (!crc->opened) {
+		spin_unlock(&crc->lock);
 		return -EINVAL;
+	}
 
 	head = crc->head;
 	tail = crc->tail;
 
 	if (CIRC_SPACE(head, tail, DRM_CRC_ENTRIES_NR) < 1) {
+		spin_unlock(&crc->lock);
 		DRM_ERROR("Overflow of CRC buffer, userspace reads too slow.\n");
 		return -ENOBUFS;
 	}
@@ -347,6 +361,10 @@ int drm_crtc_add_crc_entry(struct drm_crtc *crtc, bool has_frame,
 	head = (head + 1) & (DRM_CRC_ENTRIES_NR - 1);
 	crc->head = head;
 
+	spin_unlock(&crc->lock);
+
+	wake_up_interruptible(&crc->wq);
+
 	return 0;
 }
 EXPORT_SYMBOL_GPL(drm_crtc_add_crc_entry);