[PATCH 4.9 21/41] USB: hcd: Mark secondary HCD as dead if the primary one died

[Greg Kroah-Hartman]

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

------------------

From: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>

commit cd5a6a4fdaba150089af2afc220eae0fef74878a upstream.

Make usb_hc_died() clear the HCD_FLAG_RH_RUNNING flag for the shared
HCD and set HCD_FLAG_DEAD for it, in analogy with what is done for
the primary one.

Among other thigs, this prevents check_root_hub_suspended() from
returning -EBUSY for dead HCDs which helps to work around system
suspend issues in some situations.

This actually fixes occasional suspend failures on one of my test
machines.

Suggested-by: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
Acked-by: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/usb/core/hcd.c |    2 ++
 1 file changed, 2 insertions(+)

--- a/drivers/usb/core/hcd.c
+++ b/drivers/usb/core/hcd.c
@@ -2474,6 +2474,8 @@ void usb_hc_died (struct usb_hcd *hcd)
 	}
 	if (usb_hcd_is_primary_hcd(hcd) && hcd->shared_hcd) {
 		hcd = hcd->shared_hcd;
+		clear_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
+		set_bit(HCD_FLAG_DEAD, &hcd->flags);
 		if (hcd->rh_registered) {
 			clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);