Re: [RFD] use-counting V4L2 clocks

Guennadi Liakhovetski
2013-10-08T17:14:21Z

Hi Sylwester,

On Thu, 12 Sep 2013, Sylwester Nawrocki wrote:

> Hi Guennadi,
>
> On 09/12/2013 09:13 PM, Guennadi Liakhovetski wrote:
> > So, I think, our V4L2 clock enable / disable calls should be balanced, and
> > to enforce that a warning is helpful. Other opinions?
>
> I'd assume we should enforce those calls balanced, but I might not be
> well aware of consequences for the all existing drivers. AFAIR all drivers
> used in embedded systems follow the convention where default power state
> is off and the s_power() calls are balanced.
>
> I never ventured much into drivers that originally used tuner.s_standby()
> before it got renamed to core.s_power(). As Mauro indicated tuner devices
> assume default device power ON state, but additional s_power(1) call should
> not break things as Frank pointed out.
>
> I'd say let's make s_power(1) calls balanced, keep the warning and revisit
> drivers one by one as they get support for explicit clock control added.

Thanks for your feedback. Any more opinions?

Thanks
Guennadi

> --
> Regards,
> Sylwester