From 91db7a3fc7fe670cf1770a398a43bb4a1f776bf1 Mon Sep 17 00:00:00 2001
From: Dmitry Osipenko <dmitry.osipenko@collabora.com>
Date: Thu, 18 Aug 2022 22:33:08 +0200
Subject: [PATCH] media: cedrus: Fix endless loop in cedrus_h265_skip_bits()
Git-commit: 91db7a3fc7fe670cf1770a398a43bb4a1f776bf1
Patch-mainline: v6.1-rc1
References: git-fixes
The busy status bit may never de-assert if number of programmed skip
bits is incorrect, resulting in a kernel hang because the bit is polled
endlessly in the code. Fix it by adding timeout for the bit-polling.
This problem is reproducible by setting the data_bit_offset field of
the HEVC slice params to a wrong value by userspace.
Cc: stable@vger.kernel.org
Fixes: 7678c5462680 (media: cedrus: Fix decoding for some HEVC videos)
Reported-by: Nicolas Dufresne <nicolas.dufresne@collabora.com>
Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
Signed-off-by: Nicolas Dufresne <nicolas.dufresne@collabora.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>
Acked-by: Takashi Iwai <tiwai@suse.de>
---
drivers/staging/media/sunxi/cedrus/cedrus_h265.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/drivers/staging/media/sunxi/cedrus/cedrus_h265.c b/drivers/staging/media/sunxi/cedrus/cedrus_h265.c
index f703c585d91c..4952fc17f3e6 100644
--- a/drivers/staging/media/sunxi/cedrus/cedrus_h265.c
+++ b/drivers/staging/media/sunxi/cedrus/cedrus_h265.c
@@ -234,8 +234,9 @@ static void cedrus_h265_skip_bits(struct cedrus_dev *dev, int num)
cedrus_write(dev, VE_DEC_H265_TRIGGER,
VE_DEC_H265_TRIGGER_FLUSH_BITS |
VE_DEC_H265_TRIGGER_TYPE_N_BITS(tmp));
- while (cedrus_read(dev, VE_DEC_H265_STATUS) & VE_DEC_H265_STATUS_VLD_BUSY)
- udelay(1);
+
+ if (cedrus_wait_for(dev, VE_DEC_H265_STATUS, VE_DEC_H265_STATUS_VLD_BUSY))
+ dev_err_ratelimited(dev->dev, "timed out waiting to skip bits\n");
count += tmp;
}
--
2.35.3