On Mon, Dec 03, 2018 at 06:26:43PM +0800, Kai-Heng Feng wrote: > 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. > > Also consolidate USB2 LPM functions to usb_enable_usb2_hardware_lpm() > and usb_disable_usb2_hardware_lpm(). > > Signed-off-by: Kai-Heng Feng <kai.heng.feng@xxxxxxxxxxxxx> What kernel patch does this one "fix"? Adding a "Fixes:" tag would be good to try to figure out how far back in the kernel releases this should be backported. thanks, greg k-h
