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

This reverts commit e8fa5671183c80342d520ad81d14fa79a9d4a680.

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 <[e-mail]>
Signed-off-by: Mahesh Kumar <[e-mail]>
Cc: [e-mail]
Cc: Tomeu Vizoso <[e-mail]>
Reviewed-by: Laurent Pinchart <[e-mail]>
Reviewed-by: Maarten Lankhorst <[e-mail]>
Signed-off-by: Rodrigo Vivi <[e-mail]>
Link: https://patchwork.freedesktop.org/patch/msgid/[e-mail]

drivers/gpu/drm/drm_debugfs_crc.c

···
 	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);