Messages in this thread |  | | Date | Mon, 9 Nov 2009 10:58:58 +0000 | | From | Mark Brown <> | | Subject | Re: [alsa-devel] [PATCH 1/2 v2] ASoC: sh: fsi: Add runtime PM support |
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On Mon, Nov 09, 2009 at 11:54:47AM +0900, Kuninori Morimoto wrote: > This patch add support runtime PM. > Driver callbacks for Runtime PM are empty because > the device registers are always re-initialized after > pm_runtime_get_sync(). The Runtime PM functions replaces the > clock framework module stop bit handling in this driver.
> Signed-off-by: Kuninori Morimoto <morimoto.kuninori@renesas.com>
Hrm. I'll have to see how this plays with ASoC core pm_runtime support when that appears. It should be OK as-is, I think.
> + pm_suspend_ignore_children(&pdev->dev, true); > + pm_runtime_enable(&pdev->dev); > + pm_runtime_resume(&pdev->dev);
Why pm_suspend_ignore_all_children()? I'd not expect the device to have any children and if it did it doesn't seem like an entirely safe assumption.
> +static int fsi_runtime_nop(struct device *dev) > +{ > + /* Runtime PM callback shared between ->runtime_suspend() > + * and ->runtime_resume(). Simply returns success. > + * > + * This driver re-initializes all registers after > + * pm_runtime_get_sync() anyway so there is no need > + * to save and restore registers here. > + */ > + return 0; > +}
This sets off alarm bells but it's perfectly reasonable, especially with platforms able to put things into a low power state with no explicit driver code now they can do power domain style things like SH. I've CCed in the PM folks since this seems like a perfectly reasonable use case which ought to be handled more nicely.
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