Dne četrtek, 18. avgust 2022 ob 22:33:08 CEST je Nicolas Dufresne napisal(a):
From: Dmitry Osipenko dmitry.osipenko@collabora.com
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 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
Fixes tag would be nice.
drivers/staging/media/sunxi/cedrus/cedrus_h265.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/drivers/staging/media/sunxi/cedrus/cedrus_h265.c b/drivers/staging/media/sunxi/cedrus/cedrus_h265.c index f703c585d91c5..f0bc118021b0a 100644 --- a/drivers/staging/media/sunxi/cedrus/cedrus_h265.c +++ b/drivers/staging/media/sunxi/cedrus/cedrus_h265.c @@ -227,6 +227,7 @@ static void cedrus_h265_pred_weight_write(struct cedrus_dev *dev, static void cedrus_h265_skip_bits(struct cedrus_dev *dev, int num) { int count = 0;
u32 reg;
while (count < num) { int tmp = min(num - count, 32);
@@ -234,8 +235,9 @@ 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");
Reporting issue is nice, but better would be to propagate error, since there is no way to properly decode this slice if above code block fails.
Best regards, Jernej
count += tmp;
}