Messages in this thread | | | Date | Mon, 2 May 2011 11:53:15 +0200 (CEST) | From | Guennadi Liakhovetski <> | Subject | Re: [PATCH 2/2] dmaengine: shdma: add runtime- and system-level power management |
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On Mon, 2 May 2011, Koul, Vinod wrote:
> On Mon, 2011-05-02 at 11:04 +0200, Guennadi Liakhovetski wrote: > > On Mon, 2 May 2011, Koul, Vinod wrote: > > > > > On Fri, 2011-04-29 at 19:09 +0200, Guennadi Liakhovetski wrote: > > > > This patch extends and fixes runtime power management in the shdma > > > > driver to support powering down the DMA controller and adds support > > > > for system-level suspend and resume. > > > > > > > > Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de> > > > > --- > > > > drivers/dma/shdma.c | 68 +++++++++++++++++++++++++++++++++++++++++++++++++++ > > > > drivers/dma/shdma.h | 1 + > > > > 2 files changed, 69 insertions(+), 0 deletions(-) > > > > > > > > > > > > > > > +static int sh_dmae_runtime_suspend(struct device *dev) > > > > +{ > > > > + return 0; > > > > +} > > > Don't you need to initialize you device on resume...???? > > > > Hm, yes, but this is suspend... Resume is below. Sorry, I probably don't > > understand your question. > Opps, my question was for empty suspend. Dont you need to power off you > device.
Powering down and up is performed by platform / domain hooks. I only need to reset the hardware on wakeup. An empty .runtime_suspend() is needed by the sh-mobile specific rtpm, at least by the version, that I have, because otherwise the device status will not be changed and the resume will not be called.
> > > > + > > > > +static int sh_dmae_runtime_resume(struct device *dev) > > > > +{ > > > > + struct sh_dmae_device *shdev = dev_get_drvdata(dev); > > > > + > > > > + return sh_dmae_rst(shdev); > > > > +} > > > > + > > > > +#ifdef CONFIG_PM > > > This should be removed... > > > > You mean, these functions just won't be called, but this way we save a > > couple of bytes if PM is not set, don't we? > I meant you dont need to have this, PM is usually part of core options > which ppl enable nowadays. Do you run with PM disabled?
I actually do, but maybe that's not a very important argument. So, if the only difference is a couple of kilobytes in the kernel size, then maybe we can just keep it always enabled. There are no other side-efects to it, right?
Thanks Guennadi --- Guennadi Liakhovetski, Ph.D. Freelance Open-Source Software Developer http://www.open-technology.de/
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