On Wed, Nov 07, 2018 at 01:34:01AM +0800, Kai-Heng Feng wrote: > The QCA Rome USB Bluetooth controller has several issues once LPM gets > enabled: > - Fails to get enumerated in coldboot. [1] > - Drains more power (~ 0.2W) when the system is in S5. [2] > - Disappears after a warmboot. [2] > > The issue happens because the device lingers at LPM L1 in S5, so device > can't get enumerated even after a reboot. > > Disalbe LPM at shutdown can solve the issue. > > [1] https://bugs.launchpad.net/bugs/1757218 > [2] https://patchwork.kernel.org/patch/10607097/ > > Signed-off-by: Kai-Heng Feng <kai.heng.feng@xxxxxxxxxxxxx> > --- > drivers/usb/core/port.c | 10 ++++++++++ > 1 file changed, 10 insertions(+) > > diff --git a/drivers/usb/core/port.c b/drivers/usb/core/port.c > index 1a06a4b5fbb1..15f6924a4d84 100644 > --- a/drivers/usb/core/port.c > +++ b/drivers/usb/core/port.c > @@ -285,6 +285,15 @@ static int usb_port_runtime_suspend(struct device *dev) > } > #endif > > +static void usb_port_shutdown(struct device *dev) > +{ > + struct usb_port *port_dev = to_usb_port(dev); > + > + if (port_dev->child) > + usb_set_usb2_hardware_lpm(port_dev->child, 0); Shouldn't you also test if child->usb2_hw_lpm_enabled before calling this? Or at the least usb2_hw_lpm_capable? You did test this on a bunch of USB 1 and USB 3 devices, right? thanks, greg k-h
