On Tuesday, October 15, 2013 04:43:38 PM Alan Stern wrote: > On Tue, 15 Oct 2013, Ulf Hansson wrote: > > > For devices which don't have a .runtime_idle callback or if it returns > > 0, rpm_idle will end up in triggering a call to rpm_suspend, thus > > trying to carry out a runtime_suspend directly from runtime_idle. > > > > In the above situation we want to respect devices which has enabled > > autosuspend, we therfore append the flag sent to rpm_suspend with > > RPM_AUTO. > > > > Do note that drivers still needs to update the device last busy mark, > > to control the delay for this circumstance. > > > > Updated runtime PM documentation accordingly. > > > > Cc: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> > > Cc: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx> > > Cc: Kevin Hilman <khilman@xxxxxxxxxx> > > Cc: Rob Landley <rob@xxxxxxxxxxx> > > Cc: Chris Ball <cjb@xxxxxxxxxx> > > Cc: linux-mmc@xxxxxxxxxxxxxxx > > Signed-off-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx> > > Acked-by: Kevin Hilman <khilman@xxxxxxxxxx> > > --- > > Documentation/power/runtime_pm.txt | 14 ++++++++------ > > drivers/base/power/runtime.c | 5 +++-- > > 2 files changed, 11 insertions(+), 8 deletions(-) > > > > diff --git a/Documentation/power/runtime_pm.txt b/Documentation/power/runtime_pm.txt > > index 71d8fe4..0f54333 100644 > > --- a/Documentation/power/runtime_pm.txt > > +++ b/Documentation/power/runtime_pm.txt > > @@ -145,11 +145,13 @@ The action performed by the idle callback is totally dependent on the subsystem > > if the device can be suspended (i.e. if all of the conditions necessary for > > suspending the device are satisfied) and to queue up a suspend request for the > > device in that case. If there is no idle callback, or if the callback returns > > -0, then the PM core will attempt to carry out a runtime suspend of the device; > > -in essence, it will call pm_runtime_suspend() directly. To prevent this (for > > -example, if the callback routine has started a delayed suspend), the routine > > -should return a non-zero value. Negative error return codes are ignored by the > > -PM core. > > +0, then the PM core will attempt to carry out a runtime suspend of the device, > > +also respecting devices configured for autosuspend. In essence this means a > > +call to pm_runtime_autosuspend() (do note that drivers needs to update the > > +device last busy mark, pm_runtime_mark_last_busy(), to control the delay under > > +this circumstance). To prevent this (for example, if the callback routine has > > +started a delayed suspend), the routine must return a non-zero value. Negative > > +error return codes are ignored by the PM core. > > > > The helper functions provided by the PM core, described in Section 4, guarantee > > that the following constraints are met with respect to runtime PM callbacks for > > @@ -308,7 +310,7 @@ drivers/base/power/runtime.c and include/linux/pm_runtime.h: > > - execute the subsystem-level idle callback for the device; returns an > > error code on failure, where -EINPROGRESS means that ->runtime_idle() is > > already being executed; if there is no callback or the callback returns 0 > > - then run pm_runtime_suspend(dev) and return its result > > + then run pm_runtime_autosuspend(dev) and return its result > > > > int pm_runtime_suspend(struct device *dev); > > - execute the subsystem-level suspend callback for the device; returns 0 on > > diff --git a/drivers/base/power/runtime.c b/drivers/base/power/runtime.c > > index 268a350..72e00e6 100644 > > --- a/drivers/base/power/runtime.c > > +++ b/drivers/base/power/runtime.c > > @@ -258,7 +258,8 @@ static int __rpm_callback(int (*cb)(struct device *), struct device *dev) > > * Check if the device's runtime PM status allows it to be suspended. If > > * another idle notification has been started earlier, return immediately. If > > * the RPM_ASYNC flag is set then queue an idle-notification request; otherwise > > - * run the ->runtime_idle() callback directly. > > + * run the ->runtime_idle() callback directly. If the ->runtime_idle callback > > + * doesn't exist or if it returns 0, call rpm_suspend with the RPM_AUTO flag. > > * > > * This function must be called under dev->power.lock with interrupts disabled. > > */ > > @@ -331,7 +332,7 @@ static int rpm_idle(struct device *dev, int rpmflags) > > > > out: > > trace_rpm_return_int(dev, _THIS_IP_, retval); > > - return retval ? retval : rpm_suspend(dev, rpmflags); > > + return retval ? retval : rpm_suspend(dev, rpmflags | RPM_AUTO); > > } > > > > /** > > Acked-by: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> I've queued up this patch for 3.13. Thanks! -- I speak only for myself. Rafael J. Wysocki, Intel Open Source Technology Center. -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
