On 1/18/19 11:01 AM, Steve Longerbeam wrote:
On 1/18/19 2:24 AM, Philipp Zabel wrote:
On Thu, 2019-01-17 at 12:49 -0800, Steve Longerbeam wrote:
Disable the CSI immediately after receiving the last EOF before stream
off (and thus before disabling the IDMA channel).
This fixes a complete system hard lockup on the SabreAuto when
streaming
from the ADV7180, by repeatedly sending a stream off immediately
followed
by stream on:
while true; do v4l2-ctl -d4 --stream-mmap --stream-count=3; done
Eventually this either causes the system lockup or EOF timeouts at all
subsequent stream on, until a system reset.
The lockup occurs when disabling the IDMA channel at stream off.
Disabling
the CSI before disabling the IDMA channel appears to be a reliable
fix for
the hard lockup.
Fixes: 4a34ec8e470cb ("[media] media: imx: Add CSI subdev driver")
Reported-by: Gaël PORTAY <gael.portay@xxxxxxxxxxxxx>
Signed-off-by: Steve Longerbeam <slongerbeam@xxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
---
Changes in v2:
- restore an empty line
- Add Fixes: and Cc: stable
---
drivers/staging/media/imx/imx-media-csi.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/drivers/staging/media/imx/imx-media-csi.c
b/drivers/staging/media/imx/imx-media-csi.c
index e18f58f56dfb..e0f6f88e2e70 100644
--- a/drivers/staging/media/imx/imx-media-csi.c
+++ b/drivers/staging/media/imx/imx-media-csi.c
@@ -681,6 +681,8 @@ static void csi_idmac_stop(struct csi_priv *priv)
if (ret == 0)
v4l2_warn(&priv->sd, "wait last EOF timeout\n");
+ ipu_csi_disable(priv->csi);
+
Can you add a short comment why this call is here? Since now
csi_idmac_stop is kind of a misnomer and symmetry with csi(_idmac)_start
is broken, I think this is a bit un-obvious.
Yeah. I think a cleaner, more symmetric solution would be to split up
csi_idmac_stop.
Also note that now the error path of csi_start() will now call
ipu_csi_disable() while the CSI is disabled. This happens to work
because that just calls ipu_module_disable(), which is not refcounted.
Thanks for catching. Splitting up csi_idmac_stop will fix this.
Working on that.
Well turns out Peter Seiderer kindly provided a solution they have been
using for some time on custom imx6 hardware. His solution is to disable
the SMFC before the IDMA channel, which I have tested on the SabreAuto
and also works. This is a much simpler change, so I will post v3 that
does this instead.
Steve
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