From: Kai-Heng Feng <kai.heng.feng@canonical.com>
To: gregkh@linuxfoundation.org
Cc: linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org,
Kai-Heng Feng <kai.heng.feng@canonical.com>
Subject: [PATCH] USB: Don't enable LPM if it's already enabled
Date: Tue, 30 Oct 2018 13:54:52 +0800 [thread overview]
Message-ID: <20181030055452.25969-1-kai.heng.feng@canonical.com> (raw)
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().
So let's enable LPM for just once, as this solves the issue for the
device in question.
Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
---
drivers/usb/core/driver.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/usb/core/driver.c b/drivers/usb/core/driver.c
index 53564386ed57..e11d2eac76b6 100644
--- a/drivers/usb/core/driver.c
+++ b/drivers/usb/core/driver.c
@@ -1901,7 +1901,8 @@ 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)
+ if (enable && !udev->usb2_hw_lpm_allowed ||
+ udev->usb2_hw_lpm_enabled == enable)
return 0;
if (hcd->driver->set_usb2_hw_lpm) {
--
2.19.1
next reply other threads:[~2018-10-30 5:55 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-10-30 5:54 Kai-Heng Feng [this message]
2018-10-30 6:16 ` [PATCH] USB: Don't enable LPM if it's already enabled kbuild test robot
2018-10-30 6:30 ` kbuild test robot
2018-10-30 14:24 ` Mathias Nyman
2018-10-30 15:00 ` Alan Stern
2018-10-30 15:07 ` Kai Heng Feng
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