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@xxxxxxxxxxxxx> --- 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