From: Raghuram Hegde <[email protected]>
Observation:
If BT operations (Eg:BREDR inquiry/LE scan) were triggered
through the stack, followed by BT turn off through
'hciconfig hci0 down', the controller would still be active
and consume power.
Also, there is a possibility that a race condition/
synchronization issue might arise on the subsequent BT turn
on, as the controller might try to push the
events that were queued up before processing the HCI Reset
command.
btusb_shutdown_intel_new routine shall reset the controller
and stop all BT operation.
Advantages:
1. Power save on the platform
2. Host and controller will be in Sync.
Signed-off-by: Raghuram Hegde <[email protected]>
Signed-off-by: Chethan T N <[email protected]>
---
drivers/bluetooth/btusb.c | 19 +++++++++++++++++++
1 file changed, 19 insertions(+)
diff --git a/drivers/bluetooth/btusb.c b/drivers/bluetooth/btusb.c
index 5de0c2e59b97..3aac92be0f87 100644
--- a/drivers/bluetooth/btusb.c
+++ b/drivers/bluetooth/btusb.c
@@ -2434,6 +2434,24 @@ static int btusb_shutdown_intel(struct hci_dev *hdev)
return 0;
}
+static int btusb_shutdown_intel_new(struct hci_dev *hdev)
+{
+ struct sk_buff *skb;
+
+ /* Send HCI Reset to the controller to stop any BT activity which
+ * were triggered. This will help to save power and maintain the
+ * sync b/w Host and controller
+ */
+ skb = __hci_cmd_sync(hdev, HCI_OP_RESET, 0, NULL, HCI_INIT_TIMEOUT);
+ if (IS_ERR(skb)) {
+ bt_dev_err(hdev, "HCI reset during shutdown failed");
+ return PTR_ERR(skb);
+ }
+ kfree_skb(skb);
+
+ return 0;
+}
+
#ifdef CONFIG_PM
/* Configure an out-of-band gpio as wake-up pin, if specified in device tree */
static int marvell_config_oob_wake(struct hci_dev *hdev)
@@ -3139,6 +3157,7 @@ static int btusb_probe(struct usb_interface *intf,
hdev->manufacturer = 2;
hdev->send = btusb_send_frame_intel;
hdev->setup = btusb_setup_intel_new;
+ hdev->shutdown = btusb_shutdown_intel_new;
hdev->hw_error = btintel_hw_error;
hdev->set_diag = btintel_set_diag;
hdev->set_bdaddr = btintel_set_bdaddr;
--
2.7.4
Hi Raghuram,
> Observation:
> If BT operations (Eg:BREDR inquiry/LE scan) were triggered
> through the stack, followed by BT turn off through
> 'hciconfig hci0 down', the controller would still be active
> and consume power.
> Also, there is a possibility that a race condition/
> synchronization issue might arise on the subsequent BT turn
> on, as the controller might try to push the
> events that were queued up before processing the HCI Reset
> command.
>
> btusb_shutdown_intel_new routine shall reset the controller
> and stop all BT operation.
> Advantages:
> 1. Power save on the platform
> 2. Host and controller will be in Sync.
>
> Signed-off-by: Raghuram Hegde <[email protected]>
> Signed-off-by: Chethan T N <[email protected]>
> ---
> drivers/bluetooth/btusb.c | 19 +++++++++++++++++++
> 1 file changed, 19 insertions(+)
patch has been applied to bluetooth-next tree.
Regards
Marcel