Re: [PATCH v7 12/13] slimbus: qcom: Add runtime-pm support using clock-pause

[Srinivas Kandagatla]

Thanks for the review,

On 23/11/17 10:17, Charles Keepax wrote:
> On Wed, Nov 15, 2017 at 02:10:42PM +0000, srinivas.kandagatla@xxxxxxxxxx wrote:
> > From: Sagar Dharia <sdharia@xxxxxxxxxxxxxx>
> >
> > Slimbus HW mandates that clock-pause sequence has to be executed
> > before disabling relevant interface and core clocks.
> > Runtime-PM's autosuspend feature is used here to enter/exit low
> > power mode for Qualcomm's Slimbus controller. Autosuspend feature
> > enables driver to avoid changing power-modes too frequently since
> > entering clock-pause is an expensive sequence
> >
> > Signed-off-by: Sagar Dharia <sdharia@xxxxxxxxxxxxxx>
> > Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@xxxxxxxxxx>
> > ---
> > +
> > +#ifdef CONFIG_PM_SLEEP
> > +static int qcom_slim_suspend(struct device *dev)
> > +{
> > +	int ret = 0;
> > +
> > +	if (!pm_runtime_enabled(dev) ||
> > +		(!pm_runtime_suspended(dev))) {
> > +		dev_dbg(dev, "system suspend");
> > +		ret = qcom_slim_runtime_suspend(dev);
> > +	}
> > +
> > +	/*
> > +	 * If the clock pause failed due to active channels, there is
> > +	 * a possibility that some audio stream is active during suspend.
> > +	 * (e.g. modem usecase during suspend)
> > +	 * We dont want to return suspend failure in that case so that
> > +	 * display and relevant components can still go to suspend.
> > +	 * If there is some other error, then it should prevent
> > +	 * system level suspend
> > +	 */
> > +	if (ret == -EISCONN)
> > +		ret = 0;
>
> Who actually returns the EISCONN for this to catch? Or will that
> be added to slim_ctrl_clk_pause once support for the audio
> channels is added?

This looks like a leftover code, I will remove it in next version and we 
can add it once related code is added.



> Thanks,
> Charles
>
> > +
> > +	return ret;
> > +}