lkml.org 
[lkml]   [2018]   [Oct]   [31]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH v2] USB: Don't enable LPM if it's already enabled
Date
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>
---
v2:
- Check udev->usb2_hw_lpm_enabled before calling usb_port_resume().

drivers/usb/core/hub.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index c6077d582d29..02fa574e98ce 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -3523,7 +3523,8 @@ 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)
+ if (udev->usb2_hw_lpm_capable == 1 &&
+ !udev->usb2_hw_lpm_enabled)
usb_set_usb2_hardware_lpm(udev, 1);

/* Try to enable USB3 LTM */
--
2.19.1
\
 
 \ /
  Last update: 2018-10-31 06:53    [W:0.053 / U:0.096 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site