[PATCH 4.4 012/163] xhci: resume USB 3 roothub first

Greg Kroah-Hartman
2016-05-03T01:54:26Z

From: Mathias Nyman <mathias.nyman@linux.intel.com>

commit 671ffdff5b13314b1fc65d62cf7604b873fb5dc4 upstream.

Give USB3 devices a better chance to enumerate at USB 3 speeds if
they are connected to a suspended host.
Solves an issue with NEC uPD720200 host hanging when partially
enumerating a USB3 device as USB2 after host controller runtime resume.

Tested-by: Mike Murdoch <main.haarp@gmail.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/usb/host/xhci.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -1103,8 +1103,8 @@ int xhci_resume(struct xhci_hcd *xhci, b
/* Resume root hubs only when have pending events. */
status = readl(&xhci->op_regs->status);
if (status & STS_EINT) {
- usb_hcd_resume_root_hub(hcd);
usb_hcd_resume_root_hub(xhci->shared_hcd);
+ usb_hcd_resume_root_hub(hcd);
}
}

@@ -1119,10 +1119,10 @@ int xhci_resume(struct xhci_hcd *xhci, b

/* Re-enable port polling. */
xhci_dbg(xhci, "%s: starting port polling.\n", __func__);
- set_bit(HCD_FLAG_POLL_RH, &hcd->flags);
- usb_hcd_poll_rh_status(hcd);
set_bit(HCD_FLAG_POLL_RH, &xhci->shared_hcd->flags);
usb_hcd_poll_rh_status(xhci->shared_hcd);
+ set_bit(HCD_FLAG_POLL_RH, &hcd->flags);
+ usb_hcd_poll_rh_status(hcd);

return retval;
}