[PATCH v2] Bluetooth: btusb: Fix suspend issue for Realtek devices

[PATCH v2] Bluetooth: btusb: Fix suspend issue for Realtek devices

[Alex Lu]

From: Alex Lu <alex_lu@realsil.com.cn>

From the perspective of controller, global suspend means there is no
SET_FEATURE (DEVICE_REMOTE_WAKEUP) and controller would drop the
firmware. It would consume less power. So we should not send this kind
of SET_FEATURE when host goes to suspend state.
Otherwise, when making device enter selective suspend, host should send
SET_FEATURE to make sure the firmware remains.

Signed-off-by: Alex Lu <alex_lu@realsil.com.cn>
---
 drivers/bluetooth/btusb.c | 34 ++++++++++++++++++++++++++++++----
 1 file changed, 30 insertions(+), 4 deletions(-)

diff --git a/drivers/bluetooth/btusb.c b/drivers/bluetooth/btusb.c
index 50aed5259c2b..1995e26fa4cd 100644
--- a/drivers/bluetooth/btusb.c
+++ b/drivers/bluetooth/btusb.c
@@ -426,6 +426,7 @@ static const struct dmi_system_id btusb_needs_reset_resume_table[] = {
 #define BTUSB_DIAG_RUNNING	10
 #define BTUSB_OOB_WAKE_ENABLED	11
 #define BTUSB_HW_RESET_ACTIVE	12
+#define BTUSB_WAKEUP_DISABLE	13
 
 struct btusb_data {
 	struct hci_dev       *hdev;
@@ -1165,6 +1166,13 @@ static int btusb_open(struct hci_dev *hdev)
 	 */
 	device_wakeup_enable(&data->udev->dev);
 
+	/* Disable device remote wakeup when host is suspended
+	 * For Realtek chips, global suspend without
+	 * SET_FEATURE (DEVICE_REMOTE_WAKEUP) can save more power in device.
+	 */
+	if (test_bit(BTUSB_WAKEUP_DISABLE, &data->flags))
+		device_wakeup_disable(&data->udev->dev);
+
 	if (test_and_set_bit(BTUSB_INTR_RUNNING, &data->flags))
 		goto done;
 
@@ -1227,6 +1235,11 @@ static int btusb_close(struct hci_dev *hdev)
 		goto failed;
 
 	data->intf->needs_remote_wakeup = 0;
+
+	/* Enable remote wake up for auto-suspend */
+	if (test_bit(BTUSB_WAKEUP_DISABLE, &data->flags))
+		data->intf->needs_remote_wakeup = 1;
+
 	device_wakeup_disable(&data->udev->dev);
 	usb_autopm_put_interface(data->intf);
 
@@ -3185,11 +3198,11 @@ static int btusb_probe(struct usb_interface *intf,
 	if (id->driver_info & BTUSB_REALTEK) {
 		hdev->setup = btrtl_setup_realtek;
 
-		/* Realtek devices lose their updated firmware over suspend,
-		 * but the USB hub doesn't notice any status change.
-		 * Explicitly request a device reset on resume.
+		/* Realtek devices lose their updated firmware over global
+		 * suspend that means host doesn't send SET_FEATURE
+		 * (DEVICE_REMOTE_WAKEUP)
 		 */
-		interface_to_usbdev(intf)->quirks |= USB_QUIRK_RESET_RESUME;
+		set_bit(BTUSB_WAKEUP_DISABLE, &data->flags);
 	}
 #endif
 
@@ -3363,6 +3376,19 @@ static int btusb_suspend(struct usb_interface *intf, pm_message_t message)
 		enable_irq(data->oob_wake_irq);
 	}
 
+	/* For global suspend, Realtek devices lose the loaded fw
+	 * in them. But for autosuspend, firmware should remain.
+	 * Actually, it depends on whether the usb host sends
+	 * set feature (enable wakeup) or not.
+	 */
+	if (test_bit(BTUSB_WAKEUP_DISABLE, &data->flags)) {
+		if (PMSG_IS_AUTO(message) &&
+		    device_can_wakeup(&data->udev->dev))
+			data->udev->do_remote_wakeup = 1;
+		else if (!PMSG_IS_AUTO(message))
+			data->udev->reset_resume = 1;
+	}
+
 	return 0;
 }
 
-- 
2.19.2

Re: [PATCH v2] Bluetooth: btusb: Fix suspend issue for Realtek devices

[Marcel Holtmann]

Hi Alex,

> From the perspective of controller, global suspend means there is no
> SET_FEATURE (DEVICE_REMOTE_WAKEUP) and controller would drop the
> firmware. It would consume less power. So we should not send this kind
> of SET_FEATURE when host goes to suspend state.
> Otherwise, when making device enter selective suspend, host should send
> SET_FEATURE to make sure the firmware remains.
> 
> Signed-off-by: Alex Lu <alex_lu@realsil.com.cn>
> ---
> drivers/bluetooth/btusb.c | 34 ++++++++++++++++++++++++++++++----
> 1 file changed, 30 insertions(+), 4 deletions(-)

this one doesn’t apply cleanly to bluetooth-next. Can you please send a version that does.

Regards

Marcel

Re: [PATCH v2] Bluetooth: btusb: Fix suspend issue for Realtek devices

[Dmitry Torokhov]

On Mon, Aug 12, 2019 at 9:36 AM Marcel Holtmann <marcel@holtmann.org> wrote:
>
> Hi Alex,
>
> > From the perspective of controller, global suspend means there is no
> > SET_FEATURE (DEVICE_REMOTE_WAKEUP) and controller would drop the
> > firmware. It would consume less power. So we should not send this kind
> > of SET_FEATURE when host goes to suspend state.
> > Otherwise, when making device enter selective suspend, host should send
> > SET_FEATURE to make sure the firmware remains.
> >
> > Signed-off-by: Alex Lu <alex_lu@realsil.com.cn>
> > ---
> > drivers/bluetooth/btusb.c | 34 ++++++++++++++++++++++++++++++----
> > 1 file changed, 30 insertions(+), 4 deletions(-)
>
> this one doesn’t apply cleanly to bluetooth-next. Can you please send a version that does.

Is this a chip issue or system issue? I.e. if in some system BT
controller is wired so that it loses power over system suspend, this
is quite different form chip itself losing firmware in certain
situations, and this smells like a system issue and thus needs to be
addressed on system level.

Thanks.

-- 
Dmitry

答复: [PATCH v2] Bluetooth: btusb: Fix suspend issue for Realtek devices

[陆朱伟]

Hi Marcel,
Okay, I will send a version for bluetooth-next.

Thanks,
BRs.

> Subject: Re: [PATCH v2] Bluetooth: btusb: Fix suspend issue for Realtek devices
> 
> Hi Alex,
> 
> > From the perspective of controller, global suspend means there is no
> > SET_FEATURE (DEVICE_REMOTE_WAKEUP) and controller would drop the
> > firmware. It would consume less power. So we should not send this kind
> > of SET_FEATURE when host goes to suspend state.
> > Otherwise, when making device enter selective suspend, host should send
> > SET_FEATURE to make sure the firmware remains.
> >
> > Signed-off-by: Alex Lu <alex_lu@realsil.com.cn>
> > ---
> > drivers/bluetooth/btusb.c | 34 ++++++++++++++++++++++++++++++----
> > 1 file changed, 30 insertions(+), 4 deletions(-)
> 
> this one doesn’t apply cleanly to bluetooth-next. Can you please send a
> version that does.
> 
> Regards
> 
> Marcel
> 
> 
> ------Please consider the environment before printing this e-mail.

答复: [PATCH v2] Bluetooth: btusb: Fix suspend issue for Realtek devices

[陆朱伟]

Hi Dmitry,
It's only for Realtek devices.
If Realtek device firmware receives SET_FEATURE(device remote wakeup) usb cmd during usb is suspending, it will remains in suspend state.
Otherwise, firmware will drop itself and device will consume less power. But when host resumes, it needs to reload firmware. It can be accomplished by setting usb reset resume for device.

Thanks,
BRs.

> Subject: Re: [PATCH v2] Bluetooth: btusb: Fix suspend issue for Realtek devices
> 
> On Mon, Aug 12, 2019 at 9:36 AM Marcel Holtmann <marcel@holtmann.org>
> wrote:
> >
> > Hi Alex,
> >
> > > From the perspective of controller, global suspend means there is no
> > > SET_FEATURE (DEVICE_REMOTE_WAKEUP) and controller would drop
> the
> > > firmware. It would consume less power. So we should not send this kind
> > > of SET_FEATURE when host goes to suspend state.
> > > Otherwise, when making device enter selective suspend, host should
> send
> > > SET_FEATURE to make sure the firmware remains.
> > >
> > > Signed-off-by: Alex Lu <alex_lu@realsil.com.cn>
> > > ---
> > > drivers/bluetooth/btusb.c | 34 ++++++++++++++++++++++++++++++---
> -
> > > 1 file changed, 30 insertions(+), 4 deletions(-)
> >
> > this one doesn’t apply cleanly to bluetooth-next. Can you please send a
> version that does.
> 
> Is this a chip issue or system issue? I.e. if in some system BT
> controller is wired so that it loses power over system suspend, this
> is quite different form chip itself losing firmware in certain
> situations, and this smells like a system issue and thus needs to be
> addressed on system level.
> 
> Thanks.
> 
> --
> Dmitry
> 
> ------Please consider the environment before printing this e-mail.