| Message ID | 5542600.DvuYhMxLoT@kreacher |
|---|---|
| State | New |
| Headers | show |
| Series | PM: runtime: Simplify locking in pm_runtime_put_suppliers() | expand |
On Fri, 17 Dec 2021 at 20:16, Rafael J. Wysocki <rjw@rjwysocki.net> wrote: > > From: Rafael J. Wysocki <rafael.j.wysocki@intel.com> > > Notice that pm_runtime_put_suppliers() cannot be called with > disabled interrupts, because it may sleep (due to the device > links read locking in the non-SRCU case), and so it can use > spin_lock_irq() and spin_unlock_irq() for the locking. > > Update the function accordingly and while at it move the "put" > local variable in it into the inner block where it is used. > > This change is not expected to have any visible functional impact. > > Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org> Kind regards Uffe > --- > drivers/base/power/runtime.c | 12 ++++++++---- > 1 file changed, 8 insertions(+), 4 deletions(-) > > Index: linux-pm/drivers/base/power/runtime.c > =================================================================== > --- linux-pm.orig/drivers/base/power/runtime.c > +++ linux-pm/drivers/base/power/runtime.c > @@ -1748,8 +1748,6 @@ void pm_runtime_get_suppliers(struct dev > void pm_runtime_put_suppliers(struct device *dev) > { > struct device_link *link; > - unsigned long flags; > - bool put; > int idx; > > idx = device_links_read_lock(); > @@ -1757,11 +1755,17 @@ void pm_runtime_put_suppliers(struct dev > list_for_each_entry_rcu(link, &dev->links.suppliers, c_node, > device_links_read_lock_held()) > if (link->supplier_preactivated) { > + bool put; > + > link->supplier_preactivated = false; > - spin_lock_irqsave(&dev->power.lock, flags); > + > + spin_lock_irq(&dev->power.lock); > + > put = pm_runtime_status_suspended(dev) && > refcount_dec_not_one(&link->rpm_active); > - spin_unlock_irqrestore(&dev->power.lock, flags); > + > + spin_unlock_irq(&dev->power.lock); > + > if (put) > pm_runtime_put(link->supplier); > } > > >
Index: linux-pm/drivers/base/power/runtime.c =================================================================== --- linux-pm.orig/drivers/base/power/runtime.c +++ linux-pm/drivers/base/power/runtime.c @@ -1748,8 +1748,6 @@ void pm_runtime_get_suppliers(struct dev void pm_runtime_put_suppliers(struct device *dev) { struct device_link *link; - unsigned long flags; - bool put; int idx; idx = device_links_read_lock(); @@ -1757,11 +1755,17 @@ void pm_runtime_put_suppliers(struct dev list_for_each_entry_rcu(link, &dev->links.suppliers, c_node, device_links_read_lock_held()) if (link->supplier_preactivated) { + bool put; + link->supplier_preactivated = false; - spin_lock_irqsave(&dev->power.lock, flags); + + spin_lock_irq(&dev->power.lock); + put = pm_runtime_status_suspended(dev) && refcount_dec_not_one(&link->rpm_active); - spin_unlock_irqrestore(&dev->power.lock, flags); + + spin_unlock_irq(&dev->power.lock); + if (put) pm_runtime_put(link->supplier); }