Re: [PATCH] staging: media: tegra-video: vi: fix probe failure on skipped last port

[Dan Carpenter]

On Mon, Jul 27, 2026 at 01:10:07PM +0200, Luca Ceresoli wrote:
> Hello,
> 
> On Tue Jul 7, 2026 at 5:24 PM CEST, Hao-Qun Huang wrote:
> > tegra_vi_channels_alloc() iterates over port nodes and skips those
> > whose reg property cannot be read or whose remote endpoint fails
> > v4l2_fwnode_endpoint_parse(), leaving the negative result of the
> > failed call in ret. If that happens on the last port node, the loop
> > ends with ret still negative and tegra_vi_init() fails the whole VI
> > probe.
> >
> > The same defective port earlier in the ports node is skipped silently,
> > so probing succeeds or fails depending on the order of the port nodes.
> > The CSI equivalent, tegra_csi_channels_alloc(), returns 0
> > unconditionally after its loop and does not have this problem.
> >
> > Use a separate variable for the per-port checks so that only fatal
> > errors end up in ret.
> >
> > Fixes: 1ebaeb09830f ("media: tegra-video: Add support for external sensor capture")
> > Fixes: 2ac4035a78c9 ("media: tegra-video: Add support for x8 captures with gang ports")
> > Assisted-by: Claude:claude-fable-5
> > Signed-off-by: Hao-Qun Huang <alvinhuang0603@xxxxxxxxx>
> 
> Do you have a real use case where ths failure happens?
> 
> Also, mixing two different return values may solve a bug but makes for more
> intricated. I'd rather second a fix based on moving the whole foreach loop
> body into a subfunction, and make the foreach loop body as simple as
> calling the subfunction and handling returned errors. This would fix the
> code making it more readbale.

My instinct is that the continues should just be exits...  Why are we
accepting broken device trees?

regards,
dan carpenter