Re: [PATCH v4 0/3] media: imx: Stop stream before disabling IDMA channels

["Gaël PORTAY" <gael.portay@collabora.com>]

Steve,

On Mon, Jan 21, 2019 at 03:35:49PM -0800, Steve Longerbeam wrote:
> Repeatedly sending a stream off immediately followed by stream on can
> eventually cause a complete system hard lockup on the SabreAuto when
> streaming from the ADV7180:
> 
> 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 channels at stream off. Stopping
> the video data stream entering the IDMA channel before disabling the
> channel itself appears to be a reliable fix for the hard lockup.
> 
> In the CSI subdevice, this can be done by disabling the CSI before
> disabling the CSI IDMA channel, instead of after. In the IC-PRPENVVF
> subdevice, this can be done by stopping upstream before disabling the
> PRPENC/VF IDMA channel.
> 
> History:
> v4:
> - Disabling SMFC will have no effect if both CSI's are streaming. So
>   go back to disabling CSI before channel as in v2, but split up
>   csi_idmac_stop such that ipu_csi_disable can still be called within
>   csi_stop.
> 
> v3:
> - Switch to disabling the SMFC before the channel, instead of the CSI
>   before the channel.
> 
> v2:
> - Whitespace fixes
> - Add Fixes: and Cc: stable@vger.kernel.org
> - No functional changes.
> 
> 
> Steve Longerbeam (3):
>   media: imx: csi: Disable CSI immediately after last EOF
>   media: imx: csi: Stop upstream before disabling IDMA channel
>   media: imx: prpencvf: Stop upstream before disabling IDMA channel
> 
>  drivers/staging/media/imx/imx-ic-prpencvf.c | 26 ++++++++-----
>  drivers/staging/media/imx/imx-media-csi.c   | 42 +++++++++++++--------
>  2 files changed, 44 insertions(+), 24 deletions(-)
> 
> -- 
> 2.17.1
> 

The system is still up and running this morning after a whole night long
of tests.

You have my Tested-by.

Thanks,
Gael