Re: [PATCHv2] drm: adv7511/33: Fix adv7511_cec_init() failure handling

[John Stultz]

On Mon, Nov 20, 2017 at 12:57 PM, Hans Verkuil <hverkuil@xxxxxxxxx> wrote:
> If the device tree for a board did not specify a cec clock, then
> adv7511_cec_init would return an error, which would cause adv7511_probe()
> to fail and thus there is no HDMI output.
>
> There is no need to have adv7511_probe() fail if the CEC initialization
> fails, so just change adv7511_cec_init() to a void function. In addition,
> adv7511_cec_init() should just return silently if the cec clock isn't
> found and show a message for any other errors.
>
> An otherwise correct cleanup patch from Dan Carpenter turned this broken
> failure handling into a kernel Oops, so bisection points to commit
> 7af35b0addbc ("drm/kirin: Checking for IS_ERR() instead of NULL") rather
> than 3b1b975003e4 ("drm: adv7511/33: add HDMI CEC support").
>
> Based on earlier patches from Arnd and John.
>
> Reported-by: Naresh Kamboju <naresh.kamboju@xxxxxxxxxx>
> Cc: Xinliang Liu <xinliang.liu@xxxxxxxxxx>
> Cc: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
> Cc: Sean Paul <seanpaul@xxxxxxxxxxxx>
> Cc: Archit Taneja <architt@xxxxxxxxxxxxxx>
> Cc: John Stultz <john.stultz@xxxxxxxxxx>
> Link: https://bugs.linaro.org/show_bug.cgi?id=3345
> Link: https://lkft.validation.linaro.org/scheduler/job/48017#L3551
> Fixes: 7af35b0addbc ("drm/kirin: Checking for IS_ERR() instead of NULL")
> Fixes: 3b1b975003e4 ("drm: adv7511/33: add HDMI CEC support")
> Signed-off-by: Hans Verkuil <hans.verkuil@xxxxxxxxx>
> Tested-by: Hans Verkuil <hans.verkuil@xxxxxxxxx>
> ---
> This rework of Arnd and John's patches goes a bit further and makes
> cec_init a void function and just silently exits if there is no cec clock
> defined in the dts. I'm sure that's the reason why the kirin board failed
> on this. BTW: if the kirin board DOES support cec, then it would be nice
> if it can be hooked up in the dts!
>
> Tested with my Dragonboard and Renesas Koelsch board.
>
> Change since my previous RFC PATCH:
>
> - added static inline adv7511_cec_init to avoid #ifdef in the probe function
>   as suggested by John Stultz.

Thanks for adding the cleanup!

Seems to work well on HiKey!

Tested-by: John Stultz <john.stultz@xxxxxxxxxx>

thanks
-john