[PATCH 3.19.y-ckt 31/66] xhci: resume USB 3 roothub first

Kamal Mostafa kamal at canonical.com
Tue Apr 26 20:24:22 UTC 2016


3.19.8-ckt20 -stable review patch.  If anyone has any objections, please let me know.

---8<------------------------------------------------------------

From: Mathias Nyman <mathias.nyman at 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 at gmail.com>
Signed-off-by: Mathias Nyman <mathias.nyman at linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 drivers/usb/host/xhci.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index 37c469f..643a9f9 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -1116,8 +1116,8 @@ int xhci_resume(struct xhci_hcd *xhci, bool hibernated)
 		/* 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);
 		}
 	}
 
@@ -1132,10 +1132,10 @@ int xhci_resume(struct xhci_hcd *xhci, bool hibernated)
 
 	/* 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;
 }
-- 
2.7.4





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