On Thu, Sep 12, 2019 at 08:35:51AM +0200, Maxime Ripard wrote:
> Hi,
>
> Le mer. 11 sept. 2019 à 13:46, Corentin Labbe
> <clabbe.montjoie@xxxxxxxxx> a écrit :
> >
> > This patch enables power management on the Security System.
> >
> > Signed-off-by: Corentin Labbe <clabbe.montjoie@xxxxxxxxx>
> > ---
> > drivers/crypto/sunxi-ss/sun4i-ss-cipher.c | 5 +++
> > drivers/crypto/sunxi-ss/sun4i-ss-core.c | 42 ++++++++++++++++++++++-
> > 2 files changed, 46 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/crypto/sunxi-ss/sun4i-ss-cipher.c b/drivers/crypto/sunxi-ss/sun4i-ss-cipher.c
> > index fa4b1b47822e..1fedec9e83b0 100644
> > --- a/drivers/crypto/sunxi-ss/sun4i-ss-cipher.c
> > +++ b/drivers/crypto/sunxi-ss/sun4i-ss-cipher.c
> > @@ -10,6 +10,8 @@
> > *
> > * You could find the datasheet in Documentation/arm/sunxi.rst
> > */
> > +
> > +#include <linux/pm_runtime.h>
> > #include "sun4i-ss.h"
> >
> > static int noinline_for_stack sun4i_ss_opti_poll(struct skcipher_request *areq)
> > @@ -497,13 +499,16 @@ int sun4i_ss_cipher_init(struct crypto_tfm *tfm)
> > return PTR_ERR(op->fallback_tfm);
> > }
> >
> > + pm_runtime_get_sync(op->ss->dev);
> > return 0;
> > }
> >
> > void sun4i_ss_cipher_exit(struct crypto_tfm *tfm)
> > {
> > struct sun4i_tfm_ctx *op = crypto_tfm_ctx(tfm);
> > +
> > crypto_free_sync_skcipher(op->fallback_tfm);
> > + pm_runtime_put_sync(op->ss->dev);
> > }
> >
> > /* check and set the AES key, prepare the mode to be used */
> > diff --git a/drivers/crypto/sunxi-ss/sun4i-ss-core.c b/drivers/crypto/sunxi-ss/sun4i-ss-core.c
> > index 2c9ff01dddfc..5e6e1a308f60 100644
> > --- a/drivers/crypto/sunxi-ss/sun4i-ss-core.c
> > +++ b/drivers/crypto/sunxi-ss/sun4i-ss-core.c
> > @@ -14,6 +14,7 @@
> > #include <linux/module.h>
> > #include <linux/of.h>
> > #include <linux/platform_device.h>
> > +#include <linux/pm_runtime.h>
> > #include <crypto/scatterwalk.h>
> > #include <linux/scatterlist.h>
> > #include <linux/interrupt.h>
> > @@ -258,6 +259,37 @@ static int sun4i_ss_enable(struct sun4i_ss_ctx *ss)
> > return err;
> > }
> >
> > +#ifdef CONFIG_PM
> > +static int sun4i_ss_pm_suspend(struct device *dev)
> > +{
> > + struct sun4i_ss_ctx *ss = dev_get_drvdata(dev);
> > +
> > + sun4i_ss_disable(ss);
> > + return 0;
> > +}
> > +
> > +static int sun4i_ss_pm_resume(struct device *dev)
> > +{
> > + struct sun4i_ss_ctx *ss = dev_get_drvdata(dev);
> > +
> > + return sun4i_ss_enable(ss);
> > +}
> > +#endif
> > +
> > +const struct dev_pm_ops sun4i_ss_pm_ops = {
> > + SET_RUNTIME_PM_OPS(sun4i_ss_pm_suspend, sun4i_ss_pm_resume, NULL)
> > +};
> > +
> > +static void sun4i_ss_pm_init(struct sun4i_ss_ctx *ss)
> > +{
> > + pm_runtime_use_autosuspend(ss->dev);
> > + pm_runtime_set_autosuspend_delay(ss->dev, 1000);
> > +
> > + pm_runtime_get_noresume(ss->dev);
> > + pm_runtime_set_active(ss->dev);
> > + pm_runtime_enable(ss->dev);
> > +}
>
> It's not really clear to me what you're doing here? Can you explain?
>
I set the autosuspend state and delay.
I say that the device is active and so I "get" it.
Then I enable PM.
I do like that since I use the device later in probe(), so I need to keep it up.
At the end of probe() I put the device which go in suspend automaticaly after.
Regards
