| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-ID: <20151110144024.GG15706@odux.rfo.atmel.com>
Date: Tue, 10 Nov 2015 15:40:24 +0100
From: Ludovic Desroches <ludovic.desroches@...el.com>
To: Ulf Hansson <ulf.hansson@...aro.org>
CC: Ludovic Desroches <ludovic.desroches@...el.com>,
linux-mmc <linux-mmc@...r.kernel.org>,
"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
Nicolas Ferre <nicolas.ferre@...el.com>,
"linux-arm-kernel@...ts.infradead.org"
<linux-arm-kernel@...ts.infradead.org>
Subject: Re: [PATCH v3] mmc: sdhci at91: add PM support
On Tue, Nov 10, 2015 at 03:03:57PM +0100, Ulf Hansson wrote:
> On 10 November 2015 at 14:23, Ludovic Desroches
> <ludovic.desroches@...el.com> wrote:
> > Add runtime PM support and use runtime_force_suspend|resume() for system
> > PM.
> >
> > Signed-off-by: Ludovic Desroches <ludovic.desroches@...el.com>
> > ---
> >
> > Changes:
> > - from v2: cleanup thanks to Ulf feedback
> > - from v1: take a runtime PM centric approach
> >
> > drivers/mmc/host/sdhci-of-at91.c | 67 +++++++++++++++++++++++++++++++++++++++-
> > 1 file changed, 66 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/mmc/host/sdhci-of-at91.c b/drivers/mmc/host/sdhci-of-at91.c
> > index 06d0b50..bbac18e 100644
> > --- a/drivers/mmc/host/sdhci-of-at91.c
> > +++ b/drivers/mmc/host/sdhci-of-at91.c
> > @@ -21,6 +21,8 @@
> > #include <linux/module.h>
> > #include <linux/of.h>
> > #include <linux/of_device.h>
> > +#include <linux/pm.h>
> > +#include <linux/pm_runtime.h>
> >
> > #include "sdhci-pltfm.h"
> >
> > @@ -51,6 +53,60 @@ static const struct of_device_id sdhci_at91_dt_match[] = {
> > {}
> > };
> >
> > +#ifdef CONFIG_PM
> > +static int sdhci_at91_runtime_suspend(struct device *dev)
> > +{
> > + struct sdhci_host *host = dev_get_drvdata(dev);
> > + struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
> > + struct sdhci_at91_priv *priv = pltfm_host->priv;
> > + int ret;
> > +
> > + ret = sdhci_runtime_suspend_host(host);
> > +
> > + clk_disable_unprepare(priv->gck);
> > + clk_disable_unprepare(priv->hclock);
> > + clk_disable_unprepare(priv->mainck);
> > +
> > + return ret;
> > +}
> > +
> > +static int sdhci_at91_runtime_resume(struct device *dev)
> > +{
> > + struct sdhci_host *host = dev_get_drvdata(dev);
> > + struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
> > + struct sdhci_at91_priv *priv = pltfm_host->priv;
> > + int ret;
> > +
> > + ret = clk_prepare_enable(priv->mainck);
> > + if (ret) {
> > + dev_err(dev, "can't enable mainck\n");
> > + return ret;
> > + }
> > +
> > + ret = clk_prepare_enable(priv->hclock);
> > + if (ret) {
> > + dev_err(dev, "can't enable hclock\n");
> > + return ret;
> > + }
> > +
> > + ret = clk_prepare_enable(priv->gck);
> > + if (ret) {
> > + dev_err(dev, "can't enable gck\n");
> > + return ret;
> > + }
> > +
> > + return sdhci_runtime_resume_host(host);
> > +}
> > +#endif /* CONFIG_PM */
> > +
> > +static const struct dev_pm_ops sdhci_at91_dev_pm_ops = {
> > + SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
> > + pm_runtime_force_resume)
> > + SET_RUNTIME_PM_OPS(sdhci_at91_runtime_suspend,
> > + sdhci_at91_runtime_resume,
> > + NULL)
> > +};
> > +
> > static int sdhci_at91_probe(struct platform_device *pdev)
> > {
> > const struct of_device_id *match;
> > @@ -144,6 +200,11 @@ static int sdhci_at91_probe(struct platform_device *pdev)
> >
> > sdhci_get_of_property(pdev);
> >
> > + pm_runtime_set_active(&pdev->dev);
> > + pm_runtime_enable(&pdev->dev);
> > + pm_runtime_set_autosuspend_delay(&pdev->dev, 50);
> > + pm_runtime_use_autosuspend(&pdev->dev);
> > +
> > ret = sdhci_add_host(host);
> > if (ret)
> > goto clocks_disable_unprepare;
>
> You need to add error handling of runtime PM after this point.
>
> Typically:
> pm_runtime_disable() and pm_runtime_set_suspended() needs to be done.
I am not confortable with pm_runtime helpers, having a look to several
drivers, I see different ways to manage a probe failing and the device
removing.
I'll trust you and I'll dig later into this subject.
Regards
Ludovic
>
> > @@ -165,6 +226,10 @@ static int sdhci_at91_remove(struct platform_device *pdev)
> > struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
> > struct sdhci_at91_priv *priv = pltfm_host->priv;
> >
> > + pm_runtime_get_sync(&pdev->dev);
> > + pm_runtime_disable(&pdev->dev);
> > + pm_runtime_put_noidle(&pdev->dev);
> > +
> > sdhci_pltfm_unregister(pdev);
> >
> > clk_disable_unprepare(priv->gck);
> > @@ -178,7 +243,7 @@ static struct platform_driver sdhci_at91_driver = {
> > .driver = {
> > .name = "sdhci-at91",
> > .of_match_table = sdhci_at91_dt_match,
> > - .pm = SDHCI_PLTFM_PMOPS,
> > + .pm = &sdhci_at91_dev_pm_ops,
> > },
> > .probe = sdhci_at91_probe,
> > .remove = sdhci_at91_remove,
> > --
> > 2.5.0
> >
>
> Kind regards
> Uffe
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists