patch "USB: Consolidate LPM checks to avoid enabling LPM twice" added to usb-next

patch "USB: Consolidate LPM checks to avoid enabling LPM twice" added to usb-next

[gregkh]

This is a note to let you know that I've just added the patch titled

    USB: Consolidate LPM checks to avoid enabling LPM twice

to my usb git tree which can be found at
    git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git
in the usb-next branch.

The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)

The patch will also be merged in the next major kernel release
during the merge window.

If you have any questions about this process, please let me know.


From d7a6c0ce8d26412903c7981503bad9e1cc7c45d2 Mon Sep 17 00:00:00 2001
From: Kai-Heng Feng <kai.heng.feng@canonical.com>
Date: Sat, 12 Jan 2019 03:54:25 +0800
Subject: USB: Consolidate LPM checks to avoid enabling LPM twice
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

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: de68bab4fa96 ("usb: Don't enable USB 2.0 Link PM by default.”)
Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
Cc: stable <stable@vger.kernel.org> # after much soaking
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/usb/core/driver.c  | 11 ++++++++---
 drivers/usb/core/hub.c     | 12 ++++--------
 drivers/usb/core/message.c |  3 +--
 3 files changed, 13 insertions(+), 13 deletions(-)

diff --git a/drivers/usb/core/driver.c b/drivers/usb/core/driver.c
index c276ffc5561f..8987cec9549d 100644
--- a/drivers/usb/core/driver.c
+++ b/drivers/usb/core/driver.c
@@ -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);
 }
 
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index 7337e942e9b0..bb0830c72286 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -3251,8 +3251,7 @@ 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);
+	usb_disable_usb2_hardware_lpm(udev);
 
 	if (usb_disable_ltm(udev)) {
 		dev_err(&udev->dev, "Failed to disable LTM before suspend\n");
@@ -3290,8 +3289,7 @@ 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);
+		usb_enable_usb2_hardware_lpm(udev);
 
 		if (udev->do_remote_wakeup)
 			(void) usb_disable_remote_wakeup(udev);
@@ -3574,8 +3572,7 @@ 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);
+		usb_enable_usb2_hardware_lpm(udev);
 
 		/* Try to enable USB3 LTM */
 		usb_enable_ltm(udev);
@@ -5680,8 +5677,7 @@ 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);
+	usb_disable_usb2_hardware_lpm(udev);
 
 	/* Disable LPM while we reset the device and reinstall the alt settings.
 	 * Device-initiated LPM, and system exit latency settings are cleared
diff --git a/drivers/usb/core/message.c b/drivers/usb/core/message.c
index 35951aea7f50..4f33eb632a88 100644
--- a/drivers/usb/core/message.c
+++ b/drivers/usb/core/message.c
@@ -1243,8 +1243,7 @@ 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_disable_usb2_hardware_lpm(dev);
 		usb_unlocked_disable_lpm(dev);
 		usb_disable_ltm(dev);
 
-- 
2.20.1