btusb auto suspend

btusb auto suspend

[Peter Zijlstra]

Hi Marcel, Oliver,

What is the current status of btusb auto suspend? btusb not having this
feature basically renders BT useless on mobile devices.

I found some rfc patches and discussion over on linux-pm/-usb but
couldn't find a clear consensus.

 ~ Peter

Re: btusb auto suspend

[Marcel Holtmann]

Hi Peter,

> What is the current status of btusb auto suspend? btusb not having this
> feature basically renders BT useless on mobile devices.
> 
> I found some rfc patches and discussion over on linux-pm/-usb but
> couldn't find a clear consensus.

I think none of the patches apply anymore. So they have to be redone
against the latest -rc4 kernel or bluetooth-testing.git.

We had some battles with broken Bluetooth hardware that requires to keep
the interrupt and bulk URBs in fly, because otherwise the firmware
inside the controller can't sync them up and times out. These are all
fixed now, but nobody has looked at the auto suspend stuff. Feel free to
pick Oliver's patches up and send them for review. If you do so, please
use linux-bluetooth@vger.kernel.org since I do miss posting on LKML from
time to time.

Regards

Marcel

Re: btusb auto suspend

[Oliver Neukum]

Am Montag, 4. Mai 2009 19:29:02 schrieb Marcel Holtmann:
> Hi Peter,
>
> > What is the current status of btusb auto suspend? btusb not having this
> > feature basically renders BT useless on mobile devices.
> >
> > I found some rfc patches and discussion over on linux-pm/-usb but
> > couldn't find a clear consensus.
>
> I think none of the patches apply anymore. So they have to be redone
> against the latest -rc4 kernel or bluetooth-testing.git.

I am porting forward to Linus' tree. I thought they'd safely wait for
the next merge window.

> We had some battles with broken Bluetooth hardware that requires to keep
> the interrupt and bulk URBs in fly, because otherwise the firmware
> inside the controller can't sync them up and times out. These are all
> fixed now, but nobody has looked at the auto suspend stuff. Feel free to

It will have to be changed to work with those buggy devices.
Do you have a pointer to a page describing the problem in detail?

> pick Oliver's patches up and send them for review. If you do so, please
> use linux-bluetooth@vger.kernel.org since I do miss posting on LKML from
> time to time.

Peter, are you willing to test?

	Regards
		Oliver

Re: btusb auto suspend

[Peter Zijlstra]

On Fri, 2009-05-08 at 22:23 +0200, Oliver Neukum wrote:
> Am Montag, 4. Mai 2009 19:29:02 schrieb Marcel Holtmann:
> > Hi Peter,
> >
> > > What is the current status of btusb auto suspend? btusb not having this
> > > feature basically renders BT useless on mobile devices.
> > >
> > > I found some rfc patches and discussion over on linux-pm/-usb but
> > > couldn't find a clear consensus.
> >
> > I think none of the patches apply anymore. So they have to be redone
> > against the latest -rc4 kernel or bluetooth-testing.git.
> 
> I am porting forward to Linus' tree. I thought they'd safely wait for
> the next merge window.
> 
> > We had some battles with broken Bluetooth hardware that requires to keep
> > the interrupt and bulk URBs in fly, because otherwise the firmware
> > inside the controller can't sync them up and times out. These are all
> > fixed now, but nobody has looked at the auto suspend stuff. Feel free to
> 
> It will have to be changed to work with those buggy devices.
> Do you have a pointer to a page describing the problem in detail?
> 
> > pick Oliver's patches up and send them for review. If you do so, please
> > use linux-bluetooth@vger.kernel.org since I do miss posting on LKML from
> > time to time.
> 
> Peter, are you willing to test?

Sure, I have two laptops with integrated bluetooth to test on.

Re: btusb auto suspend

[Oliver Neukum]

[-- Attachment #1: Type: text/plain, Size: 207 bytes --]

Am Freitag, 8. Mai 2009 22:26:12 schrieb Peter Zijlstra:
> > Peter, are you willing to test?
>
> Sure, I have two laptops with integrated bluetooth to test on.

This will probably crash.

	Regards
		Oliver


[-- Attachment #2: btusb_full_20090508_1.diff --]
[-- Type: text/x-patch, Size: 9129 bytes --]

commit add1c9528961b74f98b85f43594d4e1a277d95d2
Author: Oliver Neukum <oneukum@linux-d698.(none)>
Date:   Fri May 8 22:13:40 2009 +0200

    port of full autosuspend for btusb to this rc

diff --git a/drivers/bluetooth/btusb.c b/drivers/bluetooth/btusb.c
index e70c57e..ab0c5cf 100644
--- a/drivers/bluetooth/btusb.c
+++ b/drivers/bluetooth/btusb.c
@@ -35,7 +35,7 @@
 #include <net/bluetooth/bluetooth.h>
 #include <net/bluetooth/hci_core.h>
 
-#define VERSION "0.5"
+#define VERSION "0.6"
 
 static int ignore_dga;
 static int ignore_csr;
@@ -145,6 +145,7 @@ static struct usb_device_id blacklist_table[] = {
 #define BTUSB_INTR_RUNNING	0
 #define BTUSB_BULK_RUNNING	1
 #define BTUSB_ISOC_RUNNING	2
+#define BTUSB_SUSPENDING	3
 
 struct btusb_data {
 	struct hci_dev       *hdev;
@@ -157,11 +158,15 @@ struct btusb_data {
 	unsigned long flags;
 
 	struct work_struct work;
+	struct work_struct waker;
 
 	struct usb_anchor tx_anchor;
 	struct usb_anchor intr_anchor;
 	struct usb_anchor bulk_anchor;
 	struct usb_anchor isoc_anchor;
+	struct usb_anchor deferred;
+	int tx_in_flight;
+	spinlock_t txlock;
 
 	struct usb_endpoint_descriptor *intr_ep;
 	struct usb_endpoint_descriptor *bulk_tx_ep;
@@ -174,8 +179,24 @@ struct btusb_data {
 	unsigned int sco_num;
 	int isoc_altsetting;
 	int suspend_count;
+	int did_iso_resume:1;
 };
 
+static int inc_tx(struct btusb_data *data)
+{
+	unsigned long flags;
+	int rv;
+
+	spin_lock_irqsave(&data->txlock, flags);
+	rv = test_bit(BTUSB_SUSPENDING, &data->flags);
+	if (!rv)
+		data->tx_in_flight++;
+	spin_unlock_irqrestore(&data->txlock, flags);
+
+	return rv;
+}
+
+
 static void btusb_intr_complete(struct urb *urb)
 {
 	struct hci_dev *hdev = urb->context;
@@ -202,6 +223,7 @@ static void btusb_intr_complete(struct urb *urb)
 	if (!test_bit(BTUSB_INTR_RUNNING, &data->flags))
 		return;
 
+	usb_mark_last_busy(data->udev);
 	usb_anchor_urb(urb, &data->intr_anchor);
 
 	err = usb_submit_urb(urb, GFP_ATOMIC);
@@ -327,6 +349,7 @@ static int btusb_submit_bulk_urb(struct hci_dev *hdev, gfp_t mem_flags)
 
 	urb->transfer_flags |= URB_FREE_BUFFER;
 
+	usb_mark_last_busy(data->udev);
 	usb_anchor_urb(urb, &data->bulk_anchor);
 
 	err = usb_submit_urb(urb, mem_flags);
@@ -465,6 +488,33 @@ static void btusb_tx_complete(struct urb *urb)
 {
 	struct sk_buff *skb = urb->context;
 	struct hci_dev *hdev = (struct hci_dev *) skb->dev;
+	struct btusb_data *data = hdev->driver_data;
+
+	BT_DBG("%s urb %p status %d count %d", hdev->name,
+					urb, urb->status, urb->actual_length);
+
+	if (!test_bit(HCI_RUNNING, &hdev->flags))
+		goto done;
+
+	if (!urb->status)
+		hdev->stat.byte_tx += urb->transfer_buffer_length;
+	else
+		hdev->stat.err_tx++;
+
+done:
+	spin_lock(&data->txlock);
+	data->tx_in_flight--;
+	spin_unlock(&data->txlock);
+
+	kfree(urb->setup_packet);
+
+	kfree_skb(skb);
+}
+
+static void btusb_isoc_tx_complete(struct urb *urb)
+{
+	struct sk_buff *skb = urb->context;
+	struct hci_dev *hdev = (struct hci_dev *) skb->dev;
 
 	BT_DBG("%s urb %p status %d count %d", hdev->name,
 					urb, urb->status, urb->actual_length);
@@ -490,11 +540,16 @@ static int btusb_open(struct hci_dev *hdev)
 
 	BT_DBG("%s", hdev->name);
 
+	err = usb_autopm_get_interface(data->intf);
+	if (err < 0)
+		return err;
+	data->intf->needs_remote_wakeup = 1;
+
 	if (test_and_set_bit(HCI_RUNNING, &hdev->flags))
-		return 0;
+		goto out;
 
 	if (test_and_set_bit(BTUSB_INTR_RUNNING, &data->flags))
-		return 0;
+		goto out;
 
 	err = btusb_submit_intr_urb(hdev, GFP_KERNEL);
 	if (err < 0)
@@ -509,17 +564,28 @@ static int btusb_open(struct hci_dev *hdev)
 	set_bit(BTUSB_BULK_RUNNING, &data->flags);
 	btusb_submit_bulk_urb(hdev, GFP_KERNEL);
 
+out:
+	usb_autopm_put_interface(data->intf);
 	return 0;
 
 failed:
 	clear_bit(BTUSB_INTR_RUNNING, &data->flags);
 	clear_bit(HCI_RUNNING, &hdev->flags);
+	usb_autopm_put_interface(data->intf);
 	return err;
 }
 
+static void btusb_stop_traffic(struct btusb_data *data)
+{
+	usb_kill_anchored_urbs(&data->intr_anchor);
+	usb_kill_anchored_urbs(&data->bulk_anchor);
+	usb_kill_anchored_urbs(&data->isoc_anchor);
+}
+
 static int btusb_close(struct hci_dev *hdev)
 {
 	struct btusb_data *data = hdev->driver_data;
+	int err;
 
 	BT_DBG("%s", hdev->name);
 
@@ -529,13 +595,15 @@ static int btusb_close(struct hci_dev *hdev)
 	cancel_work_sync(&data->work);
 
 	clear_bit(BTUSB_ISOC_RUNNING, &data->flags);
-	usb_kill_anchored_urbs(&data->isoc_anchor);
-
 	clear_bit(BTUSB_BULK_RUNNING, &data->flags);
-	usb_kill_anchored_urbs(&data->bulk_anchor);
-
 	clear_bit(BTUSB_INTR_RUNNING, &data->flags);
-	usb_kill_anchored_urbs(&data->intr_anchor);
+
+	btusb_stop_traffic(data);
+	err = usb_autopm_get_interface(data->intf);
+	if (!err) {
+		data->intf->needs_remote_wakeup = 0;
+		usb_autopm_put_interface(data->intf);
+	}
 
 	return 0;
 }
@@ -622,7 +690,7 @@ static int btusb_send_frame(struct sk_buff *skb)
 		urb->dev      = data->udev;
 		urb->pipe     = pipe;
 		urb->context  = skb;
-		urb->complete = btusb_tx_complete;
+		urb->complete = btusb_isoc_tx_complete;
 		urb->interval = data->isoc_tx_ep->bInterval;
 
 		urb->transfer_flags  = URB_ISO_ASAP;
@@ -633,12 +701,19 @@ static int btusb_send_frame(struct sk_buff *skb)
 				le16_to_cpu(data->isoc_tx_ep->wMaxPacketSize));
 
 		hdev->stat.sco_tx++;
-		break;
+		goto skip_waking;
 
 	default:
 		return -EILSEQ;
 	}
 
+	err = inc_tx(data);
+	if (err) {
+		usb_anchor_urb(urb, &data->deferred);
+		schedule_work(&data->waker);
+		goto out;
+	}
+skip_waking:
 	usb_anchor_urb(urb, &data->tx_anchor);
 
 	err = usb_submit_urb(urb, GFP_ATOMIC);
@@ -650,6 +725,7 @@ static int btusb_send_frame(struct sk_buff *skb)
 
 	usb_free_urb(urb);
 
+out:
 	return err;
 }
 
@@ -721,8 +797,19 @@ static void btusb_work(struct work_struct *work)
 {
 	struct btusb_data *data = container_of(work, struct btusb_data, work);
 	struct hci_dev *hdev = data->hdev;
+	int err;
 
 	if (hdev->conn_hash.sco_num > 0) {
+		if (!data->did_iso_resume) {
+			err = usb_autopm_get_interface(data->isoc);
+			if (!err) {
+				data->did_iso_resume = 1;
+			} else {
+				clear_bit(BTUSB_ISOC_RUNNING, &data->flags);
+				usb_kill_anchored_urbs(&data->isoc_anchor);
+				return;
+			}
+		}
 		if (data->isoc_altsetting != 2) {
 			clear_bit(BTUSB_ISOC_RUNNING, &data->flags);
 			usb_kill_anchored_urbs(&data->isoc_anchor);
@@ -742,9 +829,23 @@ static void btusb_work(struct work_struct *work)
 		usb_kill_anchored_urbs(&data->isoc_anchor);
 
 		__set_isoc_interface(hdev, 0);
+		if (data->did_iso_resume) {
+			data->did_iso_resume = 0;
+			usb_autopm_put_interface(data->isoc);
+		}
 	}
 }
 
+static void btusb_waker(struct work_struct *work)
+{
+	struct btusb_data *data = container_of(work, struct btusb_data, work);
+	int err;
+
+	err = usb_autopm_get_interface(data->intf);
+	if (!err)
+		usb_autopm_put_interface(data->intf);
+}
+
 static int btusb_probe(struct usb_interface *intf,
 				const struct usb_device_id *id)
 {
@@ -814,11 +915,14 @@ static int btusb_probe(struct usb_interface *intf,
 	spin_lock_init(&data->lock);
 
 	INIT_WORK(&data->work, btusb_work);
+	INIT_WORK(&data->waker, btusb_waker);
+	spin_lock_init(&data->txlock);
 
 	init_usb_anchor(&data->tx_anchor);
 	init_usb_anchor(&data->intr_anchor);
 	init_usb_anchor(&data->bulk_anchor);
 	init_usb_anchor(&data->isoc_anchor);
+	init_usb_anchor(&data->deferred);
 
 	hdev = hci_alloc_dev();
 	if (!hdev) {
@@ -946,23 +1050,43 @@ static void btusb_disconnect(struct usb_interface *intf)
 static int btusb_suspend(struct usb_interface *intf, pm_message_t message)
 {
 	struct btusb_data *data = usb_get_intfdata(intf);
+	struct hci_dev *hdev = data->hdev;
 
 	BT_DBG("intf %p", intf);
 
 	if (data->suspend_count++)
 		return 0;
 
+	spin_lock_irq(&data->txlock);
+	if (!(interface_to_usbdev(intf)->auto_pm && data->tx_in_flight)) {
+		set_bit(BTUSB_SUSPENDING, &hdev->flags);
+		spin_unlock_irq(&data->txlock);
+	} else {
+		spin_unlock_irq(&data->txlock);
+		return -EBUSY;
+	}
+
 	cancel_work_sync(&data->work);
 
+	btusb_stop_traffic(data);
 	usb_kill_anchored_urbs(&data->tx_anchor);
 
-	usb_kill_anchored_urbs(&data->isoc_anchor);
-	usb_kill_anchored_urbs(&data->bulk_anchor);
-	usb_kill_anchored_urbs(&data->intr_anchor);
-
 	return 0;
 }
 
+static void play_deferred(struct btusb_data *data)
+{
+	struct urb *urb;
+	int err;
+
+	while ((urb = usb_get_from_anchor(&data->deferred))) {
+		err = usb_submit_urb(urb, GFP_ATOMIC);
+		if (err < 0)
+			break;
+	}
+	usb_scuttle_anchored_urbs(&data->deferred);
+}
+
 static int btusb_resume(struct usb_interface *intf)
 {
 	struct btusb_data *data = usb_get_intfdata(intf);
@@ -1001,6 +1125,12 @@ static int btusb_resume(struct usb_interface *intf)
 			btusb_submit_isoc_urb(hdev, GFP_NOIO);
 	}
 
+	spin_lock_irq(&data->txlock);
+	play_deferred(data);
+	set_bit(BTUSB_SUSPENDING, &hdev->flags);
+	spin_unlock_irq(&data->txlock);
+	schedule_work(&data->work);
+
 	return 0;
 }
 
@@ -1011,6 +1141,7 @@ static struct usb_driver btusb_driver = {
 	.suspend	= btusb_suspend,
 	.resume		= btusb_resume,
 	.id_table	= btusb_table,
+	.supports_autosuspend = 1,
 };
 
 static int __init btusb_init(void)

Re: btusb auto suspend

[Peter Zijlstra]

On Fri, 2009-05-08 at 22:30 +0200, Oliver Neukum wrote:
> Am Freitag, 8. Mai 2009 22:26:12 schrieb Peter Zijlstra:
> > > Peter, are you willing to test?
> >
> > Sure, I have two laptops with integrated bluetooth to test on.
> 
> This will probably crash.

Well then we'll have to like debug it ;-)

Re: btusb auto suspend

[Marcel Holtmann]

Hi Oliver,

> > > What is the current status of btusb auto suspend? btusb not having this
> > > feature basically renders BT useless on mobile devices.
> > >
> > > I found some rfc patches and discussion over on linux-pm/-usb but
> > > couldn't find a clear consensus.
> >
> > I think none of the patches apply anymore. So they have to be redone
> > against the latest -rc4 kernel or bluetooth-testing.git.
> 
> I am porting forward to Linus' tree. I thought they'd safely wait for
> the next merge window.

I can push them into bluetooth-testing.git tree.

> > We had some battles with broken Bluetooth hardware that requires to keep
> > the interrupt and bulk URBs in fly, because otherwise the firmware
> > inside the controller can't sync them up and times out. These are all
> > fixed now, but nobody has looked at the auto suspend stuff. Feel free to
> 
> It will have to be changed to work with those buggy devices.
> Do you have a pointer to a page describing the problem in detail?

The problem is that the interrupt URBs and bulk URBs for RX have to be
always scheduled. Not matter if we have an ACL link or. Once the device
is up they have to there. Some devices just don't like it if we only
have interrupt URBs.

Regards

Marcel

Re: btusb auto suspend

[Oliver Neukum]

Am Samstag, 9. Mai 2009 00:09:41 schrieb Marcel Holtmann:
> > It will have to be changed to work with those buggy devices.
> > Do you have a pointer to a page describing the problem in detail?
>
> The problem is that the interrupt URBs and bulk URBs for RX have to be
> always scheduled. Not matter if we have an ACL link or. Once the device
> is up they have to there. Some devices just don't like it if we only
> have interrupt URBs.

OK, I see. Does the order they are submitted in matter?

	Regards
		Oliver

Re: btusb auto suspend

[Marcel Holtmann]

Hi Oliver,

> > > It will have to be changed to work with those buggy devices.
> > > Do you have a pointer to a page describing the problem in detail?
> >
> > The problem is that the interrupt URBs and bulk URBs for RX have to be
> > always scheduled. Not matter if we have an ACL link or. Once the device
> > is up they have to there. Some devices just don't like it if we only
> > have interrupt URBs.
> 
> OK, I see. Does the order they are submitted in matter?

I really don't think so, but you never know.

Regards

Marcel