Re: [PATCH v2 0/2] media: staging: imx: fix multiple video input

[Michael Tretter <m.tretter@pengutronix.de>]

On Fri, 07 Nov 2025 11:34:32 +0100, Michael Tretter wrote:
> If the IMX media pipeline is configured to receive multiple video
> inputs, the second input stream may be broken on start. This happens if
> the IMX CSI hardware has to be reconfigured for the second stream, while
> the first stream is already running.
> 
> The IMX CSI driver configures the IMX CSI in the link_validate callback.
> The media pipeline is only validated on the first start. Thus, any later
> start of the media pipeline skips the validation and directly starts
> streaming. This may leave the hardware in an inconsistent state compared
> to the driver configuration. Moving the hardware configuration to the
> stream start to make sure that the hardware is configured correctly.
> 
> Patch 1 removes the caching of the upstream mbus_config in
> csi_link_validate and explicitly request the mbus_config in csi_start,
> to get rid of this implicit dependency.
> 
> Patch 2 actually moves the hardware register setting from
> csi_link_validate to csi_start to fix the skipped hardware
> reconfiguration.

Gentle ping.

Michael

> 
> Signed-off-by: Michael Tretter <michael.tretter@pengutronix.de>
> ---
> Changes in v2:
> - Document changed locking in commit message
> - Link to v1: https://lore.kernel.org/r/20251105-media-imx-fixes-v1-0-99e48b4f5cbc@pengutronix.de
> 
> ---
> Michael Tretter (2):
>       media: staging: imx: request mbus_config in csi_start
>       media: staging: imx: configure src_mux in csi_start
> 
>  drivers/staging/media/imx/imx-media-csi.c | 84 ++++++++++++++++++-------------
>  1 file changed, 48 insertions(+), 36 deletions(-)
> ---
> base-commit: 27afd6e066cfd80ddbe22a4a11b99174ac89cced
> change-id: 20251105-media-imx-fixes-acef77c7ba12