Re: [RFD] use-counting V4L2 clocks

Sylwester Nawrocki
2013-09-12T20:47:35Z

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.

--
Regards,
Sylwester