On Thu, 18 Mar 2021 at 19:15, Rafael J. Wysocki <r...@rjwysocki.net> wrote: > > From: Rafael J. Wysocki <rafael.j.wyso...@intel.com> > > Because the PM-runtime status of the device is not updated in > __rpm_callback(), attempts to suspend the suppliers of the given > device triggered by the rpm_put_suppliers() call in there may fail. > > To fix this (1) modify __rpm_callback() to avoid attempting to > actually suspend the suppliers, but only decrease their PM-runtime > usage counters and (2) make rpm_suspend() try to suspend the suppliers > after changing the device's PM-runtime status, in analogy with the > handling of the device's parent. > > Link: > https://lore.kernel.org/linux-pm/capdykfqm06kdw_p8wxsm4dijdbho4bb6t4k50uqqvr1_cos...@mail.gmail.com/ > Fixes: 21d5c57b3726 ("PM / runtime: Use device links") > Reported-by: elaine.zhang <zhangq...@rock-chips.com> > Diagnosed-by: Ulf Hansson <ulf.hans...@linaro.org> > Signed-off-by: Rafael J. Wysocki <rafael.j.wyso...@intel.com>
Just a minor nitpick, see below. In any case: Reviewed-by: Ulf Hansson <ulf.hans...@linaro.org> > --- > drivers/base/power/runtime.c | 45 > +++++++++++++++++++++++++++++++++++++------ > 1 file changed, 39 insertions(+), 6 deletions(-) > > Index: linux-pm/drivers/base/power/runtime.c > =================================================================== > --- linux-pm.orig/drivers/base/power/runtime.c > +++ linux-pm/drivers/base/power/runtime.c > @@ -305,7 +305,7 @@ static int rpm_get_suppliers(struct devi > return 0; > } > > -static void rpm_put_suppliers(struct device *dev) > +static void __rpm_put_suppliers(struct device *dev, bool try_to_suspend) > { > struct device_link *link; > > @@ -313,10 +313,30 @@ static void rpm_put_suppliers(struct dev > device_links_read_lock_held()) { > > while (refcount_dec_not_one(&link->rpm_active)) > - pm_runtime_put(link->supplier); > + pm_runtime_put_noidle(link->supplier); > + > + if (try_to_suspend) > + pm_request_idle(link->supplier); > } > } > > +static void rpm_put_suppliers(struct device *dev) > +{ > + __rpm_put_suppliers(dev, true); > +} > + > +static void rpm_try_to_suspend_suppliers(struct device *dev) Maybe "rpm_suspend_suppliers" is sufficient for the name of the function, but I have no strong opinion. > +{ > + struct device_link *link; > + int idx = device_links_read_lock(); > + > + list_for_each_entry_rcu(link, &dev->links.suppliers, c_node, > + device_links_read_lock_held()) > + pm_request_idle(link->supplier); > + > + device_links_read_unlock(idx); > +} > + [...] Kind regards Uffe