Messages in this thread | | | From | "Rafael J. Wysocki" <> | Date | Tue, 4 Jul 2017 22:39:17 +0200 | Subject | Re: [PATCH] PM / Domains: defer dev_pm_domain_set() until genpd->attach_dev succeeds if present |
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On Thu, Jun 29, 2017 at 8:00 PM, Sudeep Holla <sudeep.holla@arm.com> wrote: > If the genpd->attach_dev or genpd->power_on fails, genpd_dev_pm_attach > may return -EPROBE_DEFER initially. However genpd_alloc_dev_data sets > the PM domain for the device unconditionally. > > When subsequent attempts are made to call genpd_dev_pm_attach, it may > return -EEXISTS checking dev->pm_domain without re-attempting to call > attach_dev or power_on. > > platform_drv_probe then attempts to call drv->probe as the return value > -EEXIST != -EPROBE_DEFER, which may end up in a situation where the > device is accessed without it's power domain switched on. > > Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> > Cc: Kevin Hilman <khilman@kernel.org> > Cc: Ulf Hansson <ulf.hansson@linaro.org> > Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Ulf, this looks like a genuine fix to me, any comments?
> --- > drivers/base/power/domain.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c > index da49a8383dc3..b195d34de888 100644 > --- a/drivers/base/power/domain.c > +++ b/drivers/base/power/domain.c > @@ -1168,8 +1168,6 @@ static struct generic_pm_domain_data *genpd_alloc_dev_data(struct device *dev, > > spin_unlock_irq(&dev->power.lock); > > - dev_pm_domain_set(dev, &genpd->domain); > - > return gpd_data; > > err_free: > @@ -1221,6 +1219,8 @@ static int genpd_add_device(struct generic_pm_domain *genpd, struct device *dev, > if (ret) > goto out; > > + dev_pm_domain_set(dev, &genpd->domain); > + > genpd->device_count++; > genpd->max_off_time_changed = true; > > -- > 2.7.4 >
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