Commit d7a6c0ce authored by Kai-Heng Feng's avatar Kai-Heng Feng Committed by Greg Kroah-Hartman
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USB: Consolidate LPM checks to avoid enabling LPM twice 



USB Bluetooth controller QCA ROME (0cf3:e007) sometimes stops working
after S3:
[ 165.110742] Bluetooth: hci0: using NVM file: qca/nvm_usb_00000302.bin
[ 168.432065] Bluetooth: hci0: Failed to send body at 4 of 1953 (-110)

After some experiments, I found that disabling LPM can workaround the
issue.

On some platforms, the USB power is cut during S3, so the driver uses
reset-resume to resume the device. During port resume, LPM gets enabled
twice, by usb_reset_and_verify_device() and usb_port_resume().

Consolidate all checks into new LPM helpers to make sure LPM only gets
enabled once.

Fixes: de68bab4 ("usb: Don't enable USB 2.0 Link PM by default.”)
Signed-off-by: default avatarKai-Heng Feng <kai.heng.feng@canonical.com>
Cc: stable <stable@vger.kernel.org> # after much soaking
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 7529b257

drivers/usb/core/driver.c

+8 −3
Original line number Diff line number Diff line
@@ -1901,9 +1901,6 @@ static int usb_set_usb2_hardware_lpm(struct usb_device *udev, int enable) 
	struct usb_hcd *hcd = bus_to_hcd(udev->bus);

	int ret = -EPERM;



	if (enable && !udev->usb2_hw_lpm_allowed)

		return 0;



	if (hcd->driver->set_usb2_hw_lpm) {

		ret = hcd->driver->set_usb2_hw_lpm(hcd, udev, enable);

		if (!ret)
@@ -1915,11 +1912,19 @@ static int usb_set_usb2_hardware_lpm(struct usb_device *udev, int enable) 


int usb_enable_usb2_hardware_lpm(struct usb_device *udev)

{

	if (!udev->usb2_hw_lpm_capable ||

	    !udev->usb2_hw_lpm_allowed ||

	    udev->usb2_hw_lpm_enabled)

		return 0;



	return usb_set_usb2_hardware_lpm(udev, 1);

}



int usb_disable_usb2_hardware_lpm(struct usb_device *udev)

{

	if (!udev->usb2_hw_lpm_enabled)

		return 0;



	return usb_set_usb2_hardware_lpm(udev, 0);

}

drivers/usb/core/hub.c

+4 −8
Original line number Diff line number Diff line
@@ -3251,7 +3251,6 @@ int usb_port_suspend(struct usb_device *udev, pm_message_t msg) 
	}



	/* disable USB2 hardware LPM */

	if (udev->usb2_hw_lpm_enabled == 1)

	usb_disable_usb2_hardware_lpm(udev);



	if (usb_disable_ltm(udev)) {
@@ -3290,7 +3289,6 @@ int usb_port_suspend(struct usb_device *udev, pm_message_t msg) 
		usb_enable_ltm(udev);

 err_ltm:

		/* Try to enable USB2 hardware LPM again */

		if (udev->usb2_hw_lpm_capable == 1)

		usb_enable_usb2_hardware_lpm(udev);



		if (udev->do_remote_wakeup)
@@ -3574,7 +3572,6 @@ int usb_port_resume(struct usb_device *udev, pm_message_t msg) 
		hub_port_logical_disconnect(hub, port1);

	} else  {

		/* Try to enable USB2 hardware LPM */

		if (udev->usb2_hw_lpm_capable == 1)

		usb_enable_usb2_hardware_lpm(udev);



		/* Try to enable USB3 LTM */
@@ -5680,7 +5677,6 @@ static int usb_reset_and_verify_device(struct usb_device *udev) 
	/* Disable USB2 hardware LPM.

	 * It will be re-enabled by the enumeration process.

	 */

	if (udev->usb2_hw_lpm_enabled == 1)

	usb_disable_usb2_hardware_lpm(udev);



	/* Disable LPM while we reset the device and reinstall the alt settings.

drivers/usb/core/message.c

+1 −2
Original line number Diff line number Diff line
@@ -1243,7 +1243,6 @@ void usb_disable_device(struct usb_device *dev, int skip_ep0) 
			dev->actconfig->interface[i] = NULL;

		}



		if (dev->usb2_hw_lpm_enabled == 1)

		usb_disable_usb2_hardware_lpm(dev);

		usb_unlocked_disable_lpm(dev);

		usb_disable_ltm(dev);

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