Revert "drm: crc: Wait for a frame before returning from open()"

This reverts commit e8fa567118.

Don't wait for first CRC during crtc_crc_open. It avoids one frame wait
during open. If application want to wait after read call, it can use
poll/read blocking read() call.

Suggested-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Mahesh Kumar <mahesh1.kumar@intel.com>
Cc: dri-devel@lists.freedesktop.org
Cc: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180821083858.26275-4-mahesh1.kumar@intel.com

drivers/gpu/drm/drm_debugfs_crc.c

@@ -228,24 +228,8 @@ static int crtc_crc_open(struct inode *inode, struct file *filep)
 	if (ret)
 		goto err;
 
-	spin_lock_irq(&crc->lock);
-	/*
-	 * 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);
-
-	if (ret)
-		goto err_disable;
-
 	return 0;
 
-err_disable:
-	crtc->funcs->set_crc_source(crtc, NULL);
 err:
 	spin_lock_irq(&crc->lock);
 	crtc_crc_cleanup(crc);