[PATCH] Bluetooth: btusb: clear remote wake on idle Intel ACPI paths

[PATCH] Bluetooth: btusb: clear remote wake on idle Intel ACPI paths

[Sean Rhodes]

Commit 6953217d9f44 ("usb: core: allow ACPI-managed hard-wired ports
to power off") allows internal USB devices on ACPI-managed hard-wired
ports to use the existing runtime power-off path. For Intel combined USB
Bluetooth controllers, btusb still keeps runtime remote wake enabled for
as long as the adapter is open, which prevents the USB PM core from
dropping the last child reference and powering the port off while idle.

Only keep runtime remote wake enabled while the controller is expected
to signal activity on its own: established links, discovery, LE scan,
LE advertising, or BR/EDR page/inquiry scan. When those are idle, clear
needs_remote_wakeup so autosuspend can power-manage the port and a later
host-initiated command can resume the device again.

Signed-off-by: Sean Rhodes <sean@starlabs.systems>
---
 drivers/bluetooth/btusb.c | 50 +++++++++++++++++++++++++++++++++++++--
 1 file changed, 48 insertions(+), 2 deletions(-)

diff --git a/drivers/bluetooth/btusb.c b/drivers/bluetooth/btusb.c
index 5e9ebf0c5312..9df8a7c3254b 100644
--- a/drivers/bluetooth/btusb.c
+++ b/drivers/bluetooth/btusb.c
@@ -901,6 +901,7 @@ struct btusb_data {
 	unsigned long flags;
 
 	bool poll_sync;
+	bool intel_combined;
 	int intr_interval;
 	struct work_struct  work;
 	struct work_struct  waker;
@@ -958,6 +959,9 @@ struct btusb_data {
 	struct qca_dump_info qca_dump;
 };
 
+static bool btusb_intel_idle_power_manageable(struct btusb_data *data);
+static bool btusb_needs_runtime_remote_wakeup(struct btusb_data *data);
+
 static void btusb_reset(struct hci_dev *hdev)
 {
 	struct btusb_data *data;
@@ -1151,12 +1155,19 @@ static inline void btusb_free_frags(struct btusb_data *data)
 
 static int btusb_recv_event(struct btusb_data *data, struct sk_buff *skb)
 {
+	int err;
+
 	if (data->intr_interval) {
 		/* Trigger dequeue immediately if an event is received */
 		schedule_delayed_work(&data->rx_work, 0);
 	}
 
-	return data->recv_event(data->hdev, skb);
+	err = data->recv_event(data->hdev, skb);
+	if (!err)
+		data->intf->needs_remote_wakeup =
+			btusb_needs_runtime_remote_wakeup(data);
+
+	return err;
 }
 
 static int btusb_recv_intr(struct btusb_data *data, void *buffer, int count)
@@ -1924,7 +1935,8 @@ static int btusb_open(struct hci_dev *hdev)
 			goto setup_fail;
 	}
 
-	data->intf->needs_remote_wakeup = 1;
+	data->intf->needs_remote_wakeup =
+		btusb_needs_runtime_remote_wakeup(data);
 
 	if (test_and_set_bit(BTUSB_INTR_RUNNING, &data->flags))
 		goto done;
@@ -1967,6 +1979,38 @@ static void btusb_stop_traffic(struct btusb_data *data)
 	usb_kill_anchored_urbs(&data->ctrl_anchor);
 }
 
+static bool btusb_intel_idle_power_manageable(struct btusb_data *data)
+{
+	struct usb_device *udev = data->udev;
+
+	return data->intel_combined && udev->parent &&
+	       usb_acpi_power_manageable(udev->parent, udev->portnum - 1);
+}
+
+static bool btusb_needs_runtime_remote_wakeup(struct btusb_data *data)
+{
+	struct hci_dev *hdev = data->hdev;
+
+	if (!btusb_intel_idle_power_manageable(data))
+		return true;
+
+	if (hci_conn_count(hdev))
+		return true;
+
+	if (hdev->discovery.state == DISCOVERY_FINDING ||
+	    hdev->discovery.state == DISCOVERY_RESOLVING)
+		return true;
+
+	if (hci_dev_test_flag(hdev, HCI_LE_SCAN) ||
+	    hci_dev_test_flag(hdev, HCI_LE_ADV) ||
+	    hci_dev_test_flag(hdev, HCI_ADVERTISING) ||
+	    test_bit(HCI_PSCAN, &hdev->flags) ||
+	    test_bit(HCI_ISCAN, &hdev->flags))
+		return true;
+
+	return false;
+}
+
 static int btusb_close(struct hci_dev *hdev)
 {
 	struct btusb_data *data = hci_get_drvdata(hdev);
@@ -4041,6 +4085,8 @@ static int btusb_probe(struct usb_interface *intf,
 	data->recv_bulk = btusb_recv_bulk;
 
 	if (id->driver_info & BTUSB_INTEL_COMBINED) {
+		data->intel_combined = true;
+
 		/* Allocate extra space for Intel device */
 		priv_size += sizeof(struct btintel_data);
 

RE: Bluetooth: btusb: clear remote wake on idle Intel ACPI paths

[bluez.test.bot]

[-- Attachment #1: Type: text/plain, Size: 2833 bytes --]

This is automated email and please do not reply to this email!

Dear submitter,

Thank you for submitting the patches to the linux bluetooth mailing list.
This is a CI test results with your patch series:
PW Link:https://patchwork.kernel.org/project/bluetooth/list/?series=1068865

---Test result---

Test Summary:
CheckPatch                    PENDING   0.61 seconds
GitLint                       PENDING   0.38 seconds
SubjectPrefix                 PASS      0.06 seconds
BuildKernel                   PASS      26.88 seconds
CheckAllWarning               PASS      29.82 seconds
CheckSparse                   PASS      28.22 seconds
BuildKernel32                 PASS      26.09 seconds
TestRunnerSetup               PASS      576.58 seconds
TestRunner_l2cap-tester       PASS      27.73 seconds
TestRunner_iso-tester         FAIL      31.08 seconds
TestRunner_bnep-tester        PASS      6.33 seconds
TestRunner_mgmt-tester        FAIL      113.55 seconds
TestRunner_rfcomm-tester      PASS      9.48 seconds
TestRunner_sco-tester         FAIL      14.67 seconds
TestRunner_ioctl-tester       PASS      10.34 seconds
TestRunner_mesh-tester        FAIL      12.53 seconds
TestRunner_smp-tester         PASS      8.52 seconds
TestRunner_userchan-tester    PASS      6.61 seconds
IncrementalBuild              PENDING   1.08 seconds

Details
##############################
Test: CheckPatch - PENDING
Desc: Run checkpatch.pl script
Output:

##############################
Test: GitLint - PENDING
Desc: Run gitlint
Output:

##############################
Test: TestRunner_iso-tester - FAIL
Desc: Run iso-tester with test-runner
Output:
BUG: KASAN: slab-use-after-free in le_read_features_complete+0x7e/0x2b0
Total: 141, Passed: 141 (100.0%), Failed: 0, Not Run: 0
##############################
Test: TestRunner_mgmt-tester - FAIL
Desc: Run mgmt-tester with test-runner
Output:
Total: 494, Passed: 489 (99.0%), Failed: 1, Not Run: 4

Failed Test Cases
Read Exp Feature - Success                           Failed       0.106 seconds
##############################
Test: TestRunner_sco-tester - FAIL
Desc: Run sco-tester with test-runner
Output:
WARNING: possible circular locking dependency detected
BUG: sleeping function called from invalid context at net/core/sock.c:3782
Total: 30, Passed: 30 (100.0%), Failed: 0, Not Run: 0
##############################
Test: TestRunner_mesh-tester - FAIL
Desc: Run mesh-tester with test-runner
Output:
Total: 10, Passed: 8 (80.0%), Failed: 2, Not Run: 0

Failed Test Cases
Mesh - Send cancel - 1                               Timed out    2.708 seconds
Mesh - Send cancel - 2                               Timed out    1.996 seconds
##############################
Test: IncrementalBuild - PENDING
Desc: Incremental build with the patches in the series
Output:



---
Regards,
Linux Bluetooth

Re: [PATCH] Bluetooth: btusb: clear remote wake on idle Intel ACPI paths

[Paul Menzel]

Dear Sean,


Thank you for your patch.

Am 18.03.26 um 20:51 schrieb Sean Rhodes:
> Commit 6953217d9f44 ("usb: core: allow ACPI-managed hard-wired ports
> to power off") allows internal USB devices on ACPI-managed hard-wired

I am unable to find the commit [1] besides on the Linux kernel list [2].

> ports to use the existing runtime power-off path. For Intel combined USB
> Bluetooth controllers, btusb still keeps runtime remote wake enabled for
> as long as the adapter is open, which prevents the USB PM core from
> dropping the last child reference and powering the port off while idle.
> 
> Only keep runtime remote wake enabled while the controller is expected
> to signal activity on its own: established links, discovery, LE scan,
> LE advertising, or BR/EDR page/inquiry scan. When those are idle, clear
> needs_remote_wakeup so autosuspend can power-manage the port and a later
> host-initiated command can resume the device again.

Could you add a test case and the device you tested with, and possible 
measurement numbers?

> Signed-off-by: Sean Rhodes <sean@starlabs.systems>
> ---
>   drivers/bluetooth/btusb.c | 50 +++++++++++++++++++++++++++++++++++++--
>   1 file changed, 48 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/bluetooth/btusb.c b/drivers/bluetooth/btusb.c
> index 5e9ebf0c5312..9df8a7c3254b 100644
> --- a/drivers/bluetooth/btusb.c
> +++ b/drivers/bluetooth/btusb.c
> @@ -901,6 +901,7 @@ struct btusb_data {
>   	unsigned long flags;
>   
>   	bool poll_sync;
> +	bool intel_combined;
>   	int intr_interval;
>   	struct work_struct  work;
>   	struct work_struct  waker;
> @@ -958,6 +959,9 @@ struct btusb_data {
>   	struct qca_dump_info qca_dump;
>   };
>   
> +static bool btusb_intel_idle_power_manageable(struct btusb_data *data);
> +static bool btusb_needs_runtime_remote_wakeup(struct btusb_data *data);
> +
>   static void btusb_reset(struct hci_dev *hdev)
>   {
>   	struct btusb_data *data;
> @@ -1151,12 +1155,19 @@ static inline void btusb_free_frags(struct btusb_data *data)
>   
>   static int btusb_recv_event(struct btusb_data *data, struct sk_buff *skb)
>   {
> +	int err;
> +
>   	if (data->intr_interval) {
>   		/* Trigger dequeue immediately if an event is received */
>   		schedule_delayed_work(&data->rx_work, 0);
>   	}
>   
> -	return data->recv_event(data->hdev, skb);
> +	err = data->recv_event(data->hdev, skb);
> +	if (!err)
> +		data->intf->needs_remote_wakeup =
> +			btusb_needs_runtime_remote_wakeup(data);
> +
> +	return err;
>   }
>   
>   static int btusb_recv_intr(struct btusb_data *data, void *buffer, int count)
> @@ -1924,7 +1935,8 @@ static int btusb_open(struct hci_dev *hdev)
>   			goto setup_fail;
>   	}
>   
> -	data->intf->needs_remote_wakeup = 1;
> +	data->intf->needs_remote_wakeup =
> +		btusb_needs_runtime_remote_wakeup(data);
>   
>   	if (test_and_set_bit(BTUSB_INTR_RUNNING, &data->flags))
>   		goto done;
> @@ -1967,6 +1979,38 @@ static void btusb_stop_traffic(struct btusb_data *data)
>   	usb_kill_anchored_urbs(&data->ctrl_anchor);
>   }
>   
> +static bool btusb_intel_idle_power_manageable(struct btusb_data *data)
> +{
> +	struct usb_device *udev = data->udev;
> +
> +	return data->intel_combined && udev->parent &&
> +	       usb_acpi_power_manageable(udev->parent, udev->portnum - 1);
> +}
> +
> +static bool btusb_needs_runtime_remote_wakeup(struct btusb_data *data)
> +{
> +	struct hci_dev *hdev = data->hdev;
> +
> +	if (!btusb_intel_idle_power_manageable(data))
> +		return true;
> +
> +	if (hci_conn_count(hdev))
> +		return true;
> +
> +	if (hdev->discovery.state == DISCOVERY_FINDING ||
> +	    hdev->discovery.state == DISCOVERY_RESOLVING)
> +		return true;
> +
> +	if (hci_dev_test_flag(hdev, HCI_LE_SCAN) ||
> +	    hci_dev_test_flag(hdev, HCI_LE_ADV) ||
> +	    hci_dev_test_flag(hdev, HCI_ADVERTISING) ||
> +	    test_bit(HCI_PSCAN, &hdev->flags) ||
> +	    test_bit(HCI_ISCAN, &hdev->flags))
> +		return true;
> +
> +	return false;
> +}
> +
>   static int btusb_close(struct hci_dev *hdev)
>   {
>   	struct btusb_data *data = hci_get_drvdata(hdev);
> @@ -4041,6 +4085,8 @@ static int btusb_probe(struct usb_interface *intf,
>   	data->recv_bulk = btusb_recv_bulk;
>   
>   	if (id->driver_info & BTUSB_INTEL_COMBINED) {
> +		data->intel_combined = true;
> +

I am not clear about this hunk. Could you please elaborate?

>   		/* Allocate extra space for Intel device */
>   		priv_size += sizeof(struct btintel_data);


Kind regards,

Paul


PS: Thank you so much for working on such details! Do you know, if this 
is also a problem on Google Chromebooks/-boxes?


[1]: 
https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git/log/?h=usb-next&qt=author&q=rhodes
[2]: 
https://lore.kernel.org/all/20260315223433.23452-1-sean@starlabs.systems/