Bluetooth: Add new HCI_QUIRK_NO_SUSPEND_NOTIFIER quirk

[ Upstream commit 219991e6be7f4a31d471611e265b72f75b2d0538 ]

Some devices, e.g. the RTL8723BS bluetooth part, some USB attached devices,
completely drop from the bus on a system-suspend. These devices will
have their driver unbound and rebound on resume (when the dropping of
the bus gets detected) and will show up as a new HCI after resume.

These devices do not benefit from the suspend / resume handling work done
by the hci_suspend_notifier. At best this unnecessarily adds some time to
the suspend/resume time. But this may also actually cause problems, if the
code doing the driver unbinding runs after the pm-notifier then the
hci_suspend_notifier code will try to talk to a device which is now in
an uninitialized state.

This commit adds a new HCI_QUIRK_NO_SUSPEND_NOTIFIER quirk which allows
drivers to opt-out of the hci_suspend_notifier when they know beforehand
that their device will be fully re-initialized / reprobed on resume.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/include/net/bluetooth/hci.h b/include/net/bluetooth/hci.h
index c8e6704..6da4b3c 100644 (file)
--- a/include/net/bluetooth/hci.h
+++ b/include/net/bluetooth/hci.h
@@ -238,6 +238,14 @@ enum {
         * during the hdev->setup vendor callback.
         */
        HCI_QUIRK_BROKEN_ERR_DATA_REPORTING,
+
+       /*
+        * When this quirk is set, then the hci_suspend_notifier is not
+        * registered. This is intended for devices which drop completely
+        * from the bus on system-suspend and which will show up as a new
+        * HCI after resume.
+        */
+       HCI_QUIRK_NO_SUSPEND_NOTIFIER,
 };
 
 /* HCI device flags */

diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
index 7a2f955..0152bc6 100644 (file)
--- a/net/bluetooth/hci_core.c
+++ b/net/bluetooth/hci_core.c
@@ -3785,10 +3785,12 @@ int hci_register_dev(struct hci_dev *hdev)
        hci_sock_dev_event(hdev, HCI_DEV_REG);
        hci_dev_hold(hdev);
 
-       hdev->suspend_notifier.notifier_call = hci_suspend_notifier;
-       error = register_pm_notifier(&hdev->suspend_notifier);
-       if (error)
-               goto err_wqueue;
+       if (!test_bit(HCI_QUIRK_NO_SUSPEND_NOTIFIER, &hdev->quirks)) {
+               hdev->suspend_notifier.notifier_call = hci_suspend_notifier;
+               error = register_pm_notifier(&hdev->suspend_notifier);
+               if (error)
+                       goto err_wqueue;
+       }
 
        queue_work(hdev->req_workqueue, &hdev->power_on);
 
@@ -3823,9 +3825,11 @@ void hci_unregister_dev(struct hci_dev *hdev)
 
        cancel_work_sync(&hdev->power_on);
 
-       hci_suspend_clear_tasks(hdev);
-       unregister_pm_notifier(&hdev->suspend_notifier);
-       cancel_work_sync(&hdev->suspend_prepare);
+       if (!test_bit(HCI_QUIRK_NO_SUSPEND_NOTIFIER, &hdev->quirks)) {
+               hci_suspend_clear_tasks(hdev);
+               unregister_pm_notifier(&hdev->suspend_notifier);
+               cancel_work_sync(&hdev->suspend_prepare);
+       }
 
        hci_dev_do_close(hdev);