| Message ID | 621452804d6d22f72438614b6687f37282d883f5.1552038717.git.viresh.kumar@linaro.org (mailing list archive) |
|---|---|
| State | Accepted, archived |
| Delegated to: | Rafael Wysocki |
| Headers | show |
| Series | [1/2] PM / wakeup: Remove timer from wakeup_source_remove() | expand |
On Friday, March 8, 2019 10:53:11 AM CET Viresh Kumar wrote: > wakeup_source_remove() is the counterpart of wakeup_source_add() helper > and must undo the initializations done by wakeup_source_add(). Currently > the timer is initialized by wakeup_source_add() but removed from > wakeup_source_drop(), which doesn't look logically correct. Also it > should be okay to call wakeup_source_add() right after calling > wakeup_source_remove(), and in that case we may end up calling > timer_setup() for a potentially scheduled timer which is surely > incorrect. > > Move the timer removal part to wakeup_source_remove() instead. > > Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> > --- > drivers/base/power/wakeup.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/drivers/base/power/wakeup.c b/drivers/base/power/wakeup.c > index f1fee72ed970..18333962e3da 100644 > --- a/drivers/base/power/wakeup.c > +++ b/drivers/base/power/wakeup.c > @@ -118,7 +118,6 @@ void wakeup_source_drop(struct wakeup_source *ws) > if (!ws) > return; > > - del_timer_sync(&ws->timer); > __pm_relax(ws); > } > EXPORT_SYMBOL_GPL(wakeup_source_drop); > @@ -205,6 +204,8 @@ void wakeup_source_remove(struct wakeup_source *ws) > list_del_rcu(&ws->entry); > raw_spin_unlock_irqrestore(&events_lock, flags); > synchronize_srcu(&wakeup_srcu); > + > + del_timer_sync(&ws->timer); > } > EXPORT_SYMBOL_GPL(wakeup_source_remove); > > I've merged it with the [2/2], rewritten the subject and changelog and queued the result as commit d856f39ac1cc ("PM / wakeup: Rework wakeup source timer cancellation").
On 11-03-19, 13:05, Rafael J. Wysocki wrote: > On Friday, March 8, 2019 10:53:11 AM CET Viresh Kumar wrote: > > wakeup_source_remove() is the counterpart of wakeup_source_add() helper > > and must undo the initializations done by wakeup_source_add(). Currently > > the timer is initialized by wakeup_source_add() but removed from > > wakeup_source_drop(), which doesn't look logically correct. Also it > > should be okay to call wakeup_source_add() right after calling > > wakeup_source_remove(), and in that case we may end up calling > > timer_setup() for a potentially scheduled timer which is surely > > incorrect. > > > > Move the timer removal part to wakeup_source_remove() instead. > > > > Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> > > --- > > drivers/base/power/wakeup.c | 3 ++- > > 1 file changed, 2 insertions(+), 1 deletion(-) > > > > diff --git a/drivers/base/power/wakeup.c b/drivers/base/power/wakeup.c > > index f1fee72ed970..18333962e3da 100644 > > --- a/drivers/base/power/wakeup.c > > +++ b/drivers/base/power/wakeup.c > > @@ -118,7 +118,6 @@ void wakeup_source_drop(struct wakeup_source *ws) > > if (!ws) > > return; > > > > - del_timer_sync(&ws->timer); > > __pm_relax(ws); > > } > > EXPORT_SYMBOL_GPL(wakeup_source_drop); > > @@ -205,6 +204,8 @@ void wakeup_source_remove(struct wakeup_source *ws) > > list_del_rcu(&ws->entry); > > raw_spin_unlock_irqrestore(&events_lock, flags); > > synchronize_srcu(&wakeup_srcu); > > + > > + del_timer_sync(&ws->timer); > > } > > EXPORT_SYMBOL_GPL(wakeup_source_remove); > > > > > > I've merged it with the [2/2], rewritten the subject and changelog and > queued the result as commit d856f39ac1cc ("PM / wakeup: Rework wakeup > source timer cancellation"). Okay, thanks. We (Android guys) want this to be backported into 4.4+ kernels via the stable tree. Can we mark this for stable in the commit itself ? Else I would be required to send this separately for all the kernels. I should have marked it for stable initially though, sorry about forgetting then.
On Tue, Mar 12, 2019 at 4:28 AM Viresh Kumar <viresh.kumar@linaro.org> wrote: > > On 11-03-19, 13:05, Rafael J. Wysocki wrote: > > On Friday, March 8, 2019 10:53:11 AM CET Viresh Kumar wrote: > > > wakeup_source_remove() is the counterpart of wakeup_source_add() helper > > > and must undo the initializations done by wakeup_source_add(). Currently > > > the timer is initialized by wakeup_source_add() but removed from > > > wakeup_source_drop(), which doesn't look logically correct. Also it > > > should be okay to call wakeup_source_add() right after calling > > > wakeup_source_remove(), and in that case we may end up calling > > > timer_setup() for a potentially scheduled timer which is surely > > > incorrect. > > > > > > Move the timer removal part to wakeup_source_remove() instead. > > > > > > Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> > > > --- > > > drivers/base/power/wakeup.c | 3 ++- > > > 1 file changed, 2 insertions(+), 1 deletion(-) > > > > > > diff --git a/drivers/base/power/wakeup.c b/drivers/base/power/wakeup.c > > > index f1fee72ed970..18333962e3da 100644 > > > --- a/drivers/base/power/wakeup.c > > > +++ b/drivers/base/power/wakeup.c > > > @@ -118,7 +118,6 @@ void wakeup_source_drop(struct wakeup_source *ws) > > > if (!ws) > > > return; > > > > > > - del_timer_sync(&ws->timer); > > > __pm_relax(ws); > > > } > > > EXPORT_SYMBOL_GPL(wakeup_source_drop); > > > @@ -205,6 +204,8 @@ void wakeup_source_remove(struct wakeup_source *ws) > > > list_del_rcu(&ws->entry); > > > raw_spin_unlock_irqrestore(&events_lock, flags); > > > synchronize_srcu(&wakeup_srcu); > > > + > > > + del_timer_sync(&ws->timer); > > > } > > > EXPORT_SYMBOL_GPL(wakeup_source_remove); > > > > > > > > > > I've merged it with the [2/2], rewritten the subject and changelog and > > queued the result as commit d856f39ac1cc ("PM / wakeup: Rework wakeup > > source timer cancellation"). > > Okay, thanks. We (Android guys) want this to be backported into 4.4+ > kernels via the stable tree. Can we mark this for stable in the commit > itself ? Else I would be required to send this separately for all the > kernels. I should have marked it for stable initially though, sorry > about forgetting then. Queued up with a CC-stable tag for 4.4 an later, thanks!
On Tue 2019-03-12 08:58:02, Viresh Kumar wrote: > On 11-03-19, 13:05, Rafael J. Wysocki wrote: > > On Friday, March 8, 2019 10:53:11 AM CET Viresh Kumar wrote: > > > wakeup_source_remove() is the counterpart of wakeup_source_add() helper > > > and must undo the initializations done by wakeup_source_add(). Currently > > > the timer is initialized by wakeup_source_add() but removed from > > > wakeup_source_drop(), which doesn't look logically correct. Also it > > > should be okay to call wakeup_source_add() right after calling > > > wakeup_source_remove(), and in that case we may end up calling > > > timer_setup() for a potentially scheduled timer which is surely > > > incorrect. > > > > > > Move the timer removal part to wakeup_source_remove() instead. > > > > I've merged it with the [2/2], rewritten the subject and changelog and > > queued the result as commit d856f39ac1cc ("PM / wakeup: Rework wakeup > > source timer cancellation"). > > Okay, thanks. We (Android guys) want this to be backported into 4.4+ > kernels via the stable tree. Can we mark this for stable in the commit > itself ? Else I would be required to send this separately for all the > kernels. I should have marked it for stable initially though, sorry > about forgetting then. Greg is normally pretty agressive about backporting everything remotely looking like a fix... But better changelog would help. How is the bug actually affecting users? Best regards, Pavel
On 12-03-19, 10:04, Pavel Machek wrote: > On Tue 2019-03-12 08:58:02, Viresh Kumar wrote: > > On 11-03-19, 13:05, Rafael J. Wysocki wrote: > > > On Friday, March 8, 2019 10:53:11 AM CET Viresh Kumar wrote: > > > > wakeup_source_remove() is the counterpart of wakeup_source_add() helper > > > > and must undo the initializations done by wakeup_source_add(). Currently > > > > the timer is initialized by wakeup_source_add() but removed from > > > > wakeup_source_drop(), which doesn't look logically correct. Also it > > > > should be okay to call wakeup_source_add() right after calling > > > > wakeup_source_remove(), and in that case we may end up calling > > > > timer_setup() for a potentially scheduled timer which is surely > > > > incorrect. > > > > > > > > Move the timer removal part to wakeup_source_remove() instead. > > > > > > > I've merged it with the [2/2], rewritten the subject and changelog and > > > queued the result as commit d856f39ac1cc ("PM / wakeup: Rework wakeup > > > source timer cancellation"). > > > > Okay, thanks. We (Android guys) want this to be backported into 4.4+ > > kernels via the stable tree. Can we mark this for stable in the commit > > itself ? Else I would be required to send this separately for all the > > kernels. I should have marked it for stable initially though, sorry > > about forgetting then. > > Greg is normally pretty agressive about backporting everything > remotely looking like a fix... > > But better changelog would help. How is the bug actually affecting > users? The Android wakelock infrastructure (not in mainline) is based on the wakeup sources stuff and that is where we found the issue. A wakelock was taken due to a bug in user driver and the board never attempts going into suspend anymore. If this patch doesn't go into the stable kernels, I would be required to send this separately for Android kernels and the Android guys will suggest getting it via stable tree. And because this fixes a potential issue it was worth trying getting it via the stable kernel :)
diff --git a/drivers/base/power/wakeup.c b/drivers/base/power/wakeup.c index f1fee72ed970..18333962e3da 100644 --- a/drivers/base/power/wakeup.c +++ b/drivers/base/power/wakeup.c @@ -118,7 +118,6 @@ void wakeup_source_drop(struct wakeup_source *ws) if (!ws) return; - del_timer_sync(&ws->timer); __pm_relax(ws); } EXPORT_SYMBOL_GPL(wakeup_source_drop); @@ -205,6 +204,8 @@ void wakeup_source_remove(struct wakeup_source *ws) list_del_rcu(&ws->entry); raw_spin_unlock_irqrestore(&events_lock, flags); synchronize_srcu(&wakeup_srcu); + + del_timer_sync(&ws->timer); } EXPORT_SYMBOL_GPL(wakeup_source_remove);
wakeup_source_remove() is the counterpart of wakeup_source_add() helper and must undo the initializations done by wakeup_source_add(). Currently the timer is initialized by wakeup_source_add() but removed from wakeup_source_drop(), which doesn't look logically correct. Also it should be okay to call wakeup_source_add() right after calling wakeup_source_remove(), and in that case we may end up calling timer_setup() for a potentially scheduled timer which is surely incorrect. Move the timer removal part to wakeup_source_remove() instead. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> --- drivers/base/power/wakeup.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)