Messages in this thread | | | Subject | Re: [PATCH v2] USB: Disable USB2 LPM at shutdown | From | Kai-Heng Feng <> | Date | Thu, 6 Jun 2019 16:06:27 +0800 |
| |
at 15:55, Kai-Heng Feng <kai.heng.feng@canonical.com> wrote:
> at 18:22, Kai-Heng Feng <kai.heng.feng@canonical.com> wrote: > >> at 00:01, Kai-Heng Feng <kai.heng.feng@canonical.com> wrote: >> >>>> On Jan 30, 2019, at 16:21, Greg KH <gregkh@linuxfoundation.org> wrote: >>>> >>>> On Thu, Jan 24, 2019 at 02:16:43PM +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. >>>>> >>>>> Disable LPM at shutdown to 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@canonical.com> >>>>> --- >>>>> v2: Use new LPM helpers. >>>>> >>>>> drivers/usb/core/port.c | 9 +++++++++ >>>>> 1 file changed, 9 insertions(+) >>>>> >>>>> diff --git a/drivers/usb/core/port.c b/drivers/usb/core/port.c >>>>> index 1a06a4b5fbb1..bbbb35fa639f 100644 >>>>> --- a/drivers/usb/core/port.c >>>>> +++ b/drivers/usb/core/port.c >>>>> @@ -285,6 +285,14 @@ 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_disable_usb2_hardware_lpm(port_dev->child); >>>>> +} >>>>> + >>>>> static const struct dev_pm_ops usb_port_pm_ops = { >>>>> #ifdef CONFIG_PM >>>>> .runtime_suspend = usb_port_runtime_suspend, >>>>> @@ -301,6 +309,7 @@ struct device_type usb_port_device_type = { >>>>> static struct device_driver usb_port_driver = { >>>>> .name = "usb", >>>>> .owner = THIS_MODULE, >>>>> + .shutdown = usb_port_shutdown, >>>>> }; >>>> >>>> So you now do this for all ports in the system, no matter what is >>>> plugged in or not. Are you _SURE_ you want to do that? It seems like a >>>> big hammer to solve just one single device's problems. >>> >>> Yes I think this should be universally applied. >>> >>> I don’t think the bug only happens to one device. Users won’t find this >>> unless they connect their laptop to a power meter. >>> >>> Platform may not completely cut off USB bus power during shutdown, >>> so the device transits to L1 after system shutdown. Now xHC is disabled >>> so nothing can bring it back to L0 or L2. >> >> It would be great if someone can come up with better ideas. >> >> We can also use other approaches, but currently this is the only way I >> can think of. > > Alan and Mathias, > > It would be great if you can review this patch, or give me some suggestion.
Can I get some advice here? I really think disabling LPM should be universally applied.
Kai-Heng
> > Kai-Heng > >> Kai-Heng >> >>> Kai-Heng >>> >>>> thanks, >>>> >>>> greg k-h
| |