xhci: always resume roothubs if xHC was reset during resume

Usb device connect may not be detected after runtime resume if
xHC is reset during resume.

In runtime resume cases xhci_resume() will only resume roothubs if there
are pending port events. If the xHC host is reset during runtime resume
due to a Save/Restore Error (SRE) then these pending port events won't be
detected as PORTSC change bits are not immediately set by host after reset.

Unconditionally resume roothubs if xHC is reset during resume to ensure
device connections are detected.

Also return early with error code if starting xHC fails after reset.

Issue was debugged and a similar solution suggested by Remi Pommarel.
Using this instead as it simplifies future refactoring.

Reported-by: Remi Pommarel <[email protected]>
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=218987
Suggested-by: Remi Pommarel <[email protected]>
Tested-by: Remi Pommarel <[email protected]>
Cc: [email protected]
Signed-off-by: Mathias Nyman <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

Author: matnyman

drivers/usb/host/xhci.c

@@ -1125,10 +1125,20 @@ int xhci_resume(struct xhci_hcd *xhci, pm_message_t msg)
 			xhci_dbg(xhci, "Start the secondary HCD\n");
 			retval = xhci_run(xhci->shared_hcd);
 		}
-
+		if (retval)
+			return retval;
+		/*
+		 * Resume roothubs unconditionally as PORTSC change bits are not
+		 * immediately visible after xHC reset
+		 */
 		hcd->state = HC_STATE_SUSPENDED;
-		if (xhci->shared_hcd)
+
+		if (xhci->shared_hcd) {
 			xhci->shared_hcd->state = HC_STATE_SUSPENDED;
+			usb_hcd_resume_root_hub(xhci->shared_hcd);
+		}
+		usb_hcd_resume_root_hub(hcd);
+
 		goto done;
 	}
 
@@ -1152,7 +1162,6 @@ int xhci_resume(struct xhci_hcd *xhci, pm_message_t msg)
 
 	xhci_dbc_resume(xhci);
 
- done:
 	if (retval == 0) {
 		/*
 		 * Resume roothubs only if there are pending events.
@@ -1178,6 +1187,7 @@ int xhci_resume(struct xhci_hcd *xhci, pm_message_t msg)
 			usb_hcd_resume_root_hub(hcd);
 		}
 	}
+done:
 	/*
 	 * If system is subject to the Quirk, Compliance Mode Timer needs to
 	 * be re-initialized Always after a system resume. Ports are subject