Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752802AbaBJLL3 (ORCPT ); Mon, 10 Feb 2014 06:11:29 -0500 Received: from mail-qa0-f49.google.com ([209.85.216.49]:52478 "EHLO mail-qa0-f49.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752772AbaBJLLZ (ORCPT ); Mon, 10 Feb 2014 06:11:25 -0500 MIME-Version: 1.0 In-Reply-To: <8738jyu1h9.fsf@paris.lan> References: <1391529538-21685-1-git-send-email-ulf.hansson@linaro.org> <1391529538-21685-6-git-send-email-ulf.hansson@linaro.org> <8738jyu1h9.fsf@paris.lan> Date: Mon, 10 Feb 2014 12:11:24 +0100 Message-ID: Subject: Re: [PATCH 05/17] mmc: mmci: Put the device into low power state at system suspend From: Ulf Hansson To: Kevin Hilman Cc: Russell King , "linux-arm-kernel@lists.infradead.org" , Alessandro Rubini , Linus Walleij , Wolfram Sang , Chris Ball , Mark Brown , "linux-kernel@vger.kernel.org" , "linux-i2c@vger.kernel.org" , "linux-spi@vger.kernel.org" , linux-mmc Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 4 February 2014 20:22, Kevin Hilman wrote: > Ulf Hansson writes: > >> Due to the available runtime PM callbacks, we are now able to put our >> device into low power state at system suspend. >> >> Earlier we could not accomplish this without trusting a power domain >> for the device to take care of it. Now we are able to cope with >> scenarios both with and without a power domain. >> >> Cc: Russell King >> Signed-off-by: Ulf Hansson >> --- >> drivers/mmc/host/mmci.c | 45 +++++++++++++++++++++++++-------------------- >> 1 file changed, 25 insertions(+), 20 deletions(-) >> >> diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c >> index c88da1c..074e0cb 100644 >> --- a/drivers/mmc/host/mmci.c >> +++ b/drivers/mmc/host/mmci.c >> @@ -1723,33 +1723,38 @@ static int mmci_remove(struct amba_device *dev) >> return 0; >> } >> >> -#ifdef CONFIG_SUSPEND >> -static int mmci_suspend(struct device *dev) >> +#ifdef CONFIG_PM_SLEEP >> +static int mmci_suspend_late(struct device *dev) >> { >> - struct amba_device *adev = to_amba_device(dev); >> - struct mmc_host *mmc = amba_get_drvdata(adev); >> + int ret = 0; >> >> - if (mmc) { >> - struct mmci_host *host = mmc_priv(mmc); >> - pm_runtime_get_sync(dev); >> - writel(0, host->base + MMCIMASK0); >> - } >> + if (pm_runtime_status_suspended(dev)) >> + return 0; >> >> - return 0; >> + if (dev->pm_domain && dev->pm_domain->ops.runtime_suspend) >> + ret = dev->pm_domain->ops.runtime_suspend(dev); >> + else >> + ret = dev->bus->pm->runtime_suspend(dev); >> + >> + if (!ret) >> + pm_runtime_set_suspended(dev); > > Isn't this basically open-coding pm_runtime_suspend()... It is similar, but with once big difference. Since the PM core prevents pm_runtime_suspend() from invoking our ->runtime_suspend callback during system suspend (it does so by invoking pm_runtime_get_sync() before starting the suspend sequence), we then need to make the driver handle that by itself. > >> + return ret; >> } >> >> -static int mmci_resume(struct device *dev) >> +static int mmci_resume_early(struct device *dev) >> { >> - struct amba_device *adev = to_amba_device(dev); >> - struct mmc_host *mmc = amba_get_drvdata(adev); >> + int ret = 0; >> >> - if (mmc) { >> - struct mmci_host *host = mmc_priv(mmc); >> - writel(MCI_IRQENABLE, host->base + MMCIMASK0); >> - pm_runtime_put(dev); >> - } >> + if (pm_runtime_status_suspended(dev)) >> + return 0; >> >> - return 0; >> + if (dev->pm_domain && dev->pm_domain->ops.runtime_resume) >> + ret = dev->pm_domain->ops.runtime_resume(dev); >> + else >> + ret = dev->bus->pm->runtime_resume(dev); >> + >> + return ret; > > ...and this is pm_runtime_resume()? (though both terribly simplified.) Correct, but again with a big difference. See comment above. > > This is starting to show that building with PM_SLEEP but not PM_RUNTIME > is going to force open-coding a lot of stuff that the runtime PM > framework already provides. So either we need some helper functions so > we're not sprinkling manual calls to bus/pm_domain callbacks all over I have send a patch a while ago for the PM core, that tried to implement something similar like this, I wasn't accepted. I will follow up on that asap. Still, do you think we could go ahead with this patch? If/when we can get an acceptance for a PM runtime helper function in the PM core, we can easily convert to use it later on. > the place, or maybe where we need to go is have a way for platforms that > really are "runtime PM centric" to declare that even PM_SLEEP depends on > PM_RUNTIME. > > I'm trying to thing of a good reason to not make PM_SLEEP depend on > PM_RUNTIME for platforms like this. This wont help. The PM core will still prevent the runtime_suspend callback from being invoked during system suspend. Kind regards Ulf Hansson > > Kevin > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/