Hi, On 07/12/2016 09:48 AM, Lipengcheng wrote: > Hi, > >> -----Original Message----- >> From: Lu Baolu [mailto:baolu.lu@xxxxxxxxxxxxxxx] >> Sent: Tuesday, July 12, 2016 8:42 AM >> To: Lipengcheng; gregkh@xxxxxxxxxxxxxxxxxxx; stern@xxxxxxxxxxxxxxxxxxx; chasemetzger15@xxxxxxxxx; mathias.nyman@xxxxxxxxxxxxxxx; >> oneukum@xxxxxxxx; jun.li@xxxxxxxxxxxxx >> Cc: linux-usb@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx >> Subject: Re: [PATCH] usb:solve resume usb device identification problem >> >> Hi, >> >> On 07/11/2016 08:57 PM, Pengcheng Li wrote: >>> A usb device in the connection state. Then host is suspend and resume. >>> But the usb device could not be at the right speed. We should be reset >>> the reset. >> Have you tried applying XHCI_RESET_ON_RESUME quirk to your host controller driver? Is your usb device self powered? >> > I do not apply XHCI_RESET_ON_RESUME quir to my host controller driver. I select no pci platform. Our usb device is not self powered. This quirk is not pci specific. >> Best regards, >> Lu Baolu >> >>> Signed-off-by: Pengcheng Li <lpc.li@xxxxxxxxxxxxx> >>> --- >>> drivers/usb/core/hub.c | 6 +++++- >>> 1 file changed, 5 insertions(+), 1 deletion(-) >>> >>> diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c index >>> bee1351..cd71bb3 100644 >>> --- a/drivers/usb/core/hub.c >>> +++ b/drivers/usb/core/hub.c >>> @@ -3455,7 +3455,7 @@ int usb_port_resume(struct usb_device *udev, pm_message_t msg) >>> struct usb_hub *hub = usb_hub_to_struct_hub(udev->parent); >>> struct usb_port *port_dev = hub->ports[udev->portnum - 1]; >>> int port1 = udev->portnum; >>> - int status; >>> + int status, retval; >>> u16 portchange, portstatus; >>> >>> if (!test_and_set_bit(port1, hub->child_usage_bits)) { @@ -3512,6 >>> +3512,10 @@ int usb_port_resume(struct usb_device *udev, pm_message_t msg) >>> } >>> } >>> >>> + retval = hub_port_reset(hub, port1, udev, HUB_ROOT_RESET_TIME, false); >>> + if (retval < 0) >>> + hub_port_disable(hub, port1, 0); >>> + If I understand it right, this is a "host + device" specific issue. This line of code might solve your issue, but it impacts all other hosts and devices which don't have such problem. Best regards, Lu Baolu -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
