[PATCH] Bluetooth: Re-order clearing suspend tasks

[PATCH] Bluetooth: Re-order clearing suspend tasks

[Abhishek Pandit-Subedi]

Unregister_pm_notifier is a blocking call so suspend tasks should be
cleared beforehand. Otherwise, the notifier will wait for completion
before returning (and we encounter a 2s timeout on resume).

Fixes: 0e9952804ec9c8 (Bluetooth: Clear suspend tasks on unregister)
Signed-off-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
---
Should have caught that unregister_pm_notifier was blocking last time
but when testing the earlier patch, I got unlucky and saw that the error
message was never hit (the suspend timeout).

When re-testing this patch on the same device, I was able to reproduce
the problem on an older build with the 0e9952804ec9c8 but not on a newer
build with the same patch. Changing the order correctly fixes it
everywhere. Confirmed this by adding debug logs in btusb_disconnect and
hci_suspend_notifier to confirm what order things were getting called.

Sorry about the churn. Next I'm going try to do something about the palm
shaped indentation on my forehead...

 net/bluetooth/hci_core.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
index efc0fe2b47dac2..be9cdf5dabe5dc 100644
--- a/net/bluetooth/hci_core.c
+++ b/net/bluetooth/hci_core.c
@@ -3794,8 +3794,8 @@ void hci_unregister_dev(struct hci_dev *hdev)
 
 	cancel_work_sync(&hdev->power_on);
 
-	unregister_pm_notifier(&hdev->suspend_notifier);
 	hci_suspend_clear_tasks(hdev);
+	unregister_pm_notifier(&hdev->suspend_notifier);
 	cancel_work_sync(&hdev->suspend_prepare);
 
 	hci_dev_do_close(hdev);
-- 
2.28.0.618.gf4bc123cb7-goog

Re: [PATCH] Bluetooth: Re-order clearing suspend tasks

[Marcel Holtmann]

Hi Abhishek,

> Unregister_pm_notifier is a blocking call so suspend tasks should be
> cleared beforehand. Otherwise, the notifier will wait for completion
> before returning (and we encounter a 2s timeout on resume).
> 
> Fixes: 0e9952804ec9c8 (Bluetooth: Clear suspend tasks on unregister)
> Signed-off-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
> ---
> Should have caught that unregister_pm_notifier was blocking last time
> but when testing the earlier patch, I got unlucky and saw that the error
> message was never hit (the suspend timeout).
> 
> When re-testing this patch on the same device, I was able to reproduce
> the problem on an older build with the 0e9952804ec9c8 but not on a newer
> build with the same patch. Changing the order correctly fixes it
> everywhere. Confirmed this by adding debug logs in btusb_disconnect and
> hci_suspend_notifier to confirm what order things were getting called.
> 
> Sorry about the churn. Next I'm going try to do something about the palm
> shaped indentation on my forehead...
> 
> net/bluetooth/hci_core.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)

patch has been applied to bluetooth-next tree.

Regards

Marcel

[PATCH] Bluetooth: Re-order clearing suspend tasks

[Abhishek Pandit-Subedi]

Unregister_pm_notifier is a blocking call so suspend tasks should be
cleared beforehand. Otherwise, the notifier will wait for completion
before returning (and we encounter a 2s timeout on resume).

Fixes: 0e9952804ec9c8 (Bluetooth: Clear suspend tasks on unregister)
Signed-off-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
---
Should have caught that unregister_pm_notifier was blocking last time
but when testing the earlier patch, I got unlucky and saw that the error
message was never hit (the suspend timeout).

When re-testing this patch on the same device, I was able to reproduce
the problem on an older build with the 0e9952804ec9c8 but not on a newer
build with the same patch. Changing the order correctly fixes it
everywhere. Confirmed this by adding debug logs in btusb_disconnect and
hci_suspend_notifier to confirm what order things were getting called.

Sorry about the churn. Next I'm going try to do something about the palm
shaped indentation on my forehead...

 net/bluetooth/hci_core.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
index efc0fe2b47dac2..be9cdf5dabe5dc 100644
--- a/net/bluetooth/hci_core.c
+++ b/net/bluetooth/hci_core.c
@@ -3794,8 +3794,8 @@ void hci_unregister_dev(struct hci_dev *hdev)
 
 	cancel_work_sync(&hdev->power_on);
 
-	unregister_pm_notifier(&hdev->suspend_notifier);
 	hci_suspend_clear_tasks(hdev);
+	unregister_pm_notifier(&hdev->suspend_notifier);
 	cancel_work_sync(&hdev->suspend_prepare);
 
 	hci_dev_do_close(hdev);
-- 
2.28.0.618.gf4bc123cb7-goog