From 99c66bc051e7407fe0bf0607b142ec0be1a1d1dd Mon Sep 17 00:00:00 2001
From: "Kristian H. Kristensen" <hoegsberg@gmail.com>
Date: Wed, 19 Dec 2018 08:57:41 -0800
Subject: [PATCH] drm/msm: Unblock writer if reader closes file
Git-commit: 99c66bc051e7407fe0bf0607b142ec0be1a1d1dd
Patch-mainline: v5.0-rc4
References: bsc#1051510

Prevents deadlock when fifo is full and reader closes file.

Signed-off-by: Kristian H. Kristensen <hoegsberg@chromium.org>
Signed-off-by: Rob Clark <robdclark@gmail.com>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/gpu/drm/msm/msm_rd.c |    7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

--- a/drivers/gpu/drm/msm/msm_rd.c
+++ b/drivers/gpu/drm/msm/msm_rd.c
@@ -115,7 +115,9 @@ static void rd_write(struct msm_rd_state
 		char *fptr = &fifo->buf[fifo->head];
 		int n;
 
-		wait_event(rd->fifo_event, circ_space(&rd->fifo) > 0);
+		wait_event(rd->fifo_event, circ_space(&rd->fifo) > 0 || !rd->open);
+		if (!rd->open)
+			return;
 
 		/* Note that smp_load_acquire() is not strictly required
 		 * as CIRC_SPACE_TO_END() does not access the tail more
@@ -213,7 +215,10 @@ out:
 static int rd_release(struct inode *inode, struct file *file)
 {
 	struct msm_rd_state *rd = inode->i_private;
+
 	rd->open = false;
+	wake_up_all(&rd->fifo_event);
+
 	return 0;
 }