diff --git a/Documentation/usb/persist.txt b/Documentation/usb/persist.txt index d56cb1a1155073987fc2ca108c766f03100d35cf..074b159b77c20344aaa0a4abf7becc8603a2a065 100644 --- a/Documentation/usb/persist.txt +++ b/Documentation/usb/persist.txt @@ -81,8 +81,11 @@ re-enumeration shows that the device now attached to that port has the same descriptors as before, including the Vendor and Product IDs, then the kernel continues to use the same device structure. In effect, the kernel treats the device as though it had merely been reset instead of -unplugged. The same thing happens if the host controller is in the -expected state but a USB device was unplugged and then replugged. +unplugged. + +The same thing happens if the host controller is in the expected state +but a USB device was unplugged and then replugged, or if a USB device +fails to carry out a normal resume. If no device is now attached to the port, or if the descriptors are different from what the kernel remembers, then the treatment is what diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c index f1efabbc1ca22d85c5fca99f59b40c93185beab2..107e1d25ddec3fbe0a485191131dad985342c8ff 100644 --- a/drivers/usb/core/hub.c +++ b/drivers/usb/core/hub.c @@ -1822,9 +1822,15 @@ static int check_port_resume_type(struct usb_device *udev, status = -ENODEV; } - /* Can't do a normal resume if the port isn't enabled */ - else if (!(portstatus & USB_PORT_STAT_ENABLE) && !udev->reset_resume) - status = -ENODEV; + /* Can't do a normal resume if the port isn't enabled, + * so try a reset-resume instead. + */ + else if (!(portstatus & USB_PORT_STAT_ENABLE) && !udev->reset_resume) { + if (udev->persist_enabled) + udev->reset_resume = 1; + else + status = -ENODEV; + } if (status) { dev_dbg(hub->intfdev, @@ -1973,6 +1979,7 @@ static int finish_port_resume(struct usb_device *udev) * resumed. */ if (udev->reset_resume) + retry_reset_resume: status = usb_reset_and_verify_device(udev); /* 10.5.4.5 says be sure devices in the tree are still there. @@ -1984,6 +1991,13 @@ static int finish_port_resume(struct usb_device *udev) status = usb_get_status(udev, USB_RECIP_DEVICE, 0, &devstatus); if (status >= 0) status = (status > 0 ? 0 : -ENODEV); + + /* If a normal resume failed, try doing a reset-resume */ + if (status && !udev->reset_resume && udev->persist_enabled) { + dev_dbg(&udev->dev, "retry with reset-resume\n"); + udev->reset_resume = 1; + goto retry_reset_resume; + } } if (status) {