libpayload: usb: xhci: Treat port reset as a port status change

If a port is connected before and after an xhci controller reset, the
PORTSC CSC bit may not be asserted. Add an additional check in
xhci_rh_port_status_changed for the PRC bit so we can correctly handle
ports in such a state.

Signed-off-by: Shawn Nematbakhsh <shawnn@chromium.org>
Change-Id: I2d623aae647ab13711badd7211ab467afdc69548
Reviewed-on: https://chromium-review.googlesource.com/189394
Reviewed-by: Julius Werner <jwerner@chromium.org>
(cherry picked from commit ee7c3ea182b35bb6ce3c62f301c4515714f6e654)
Signed-off-by: Isaac Christensen <isaac.christensen@se-eng.com>
Reviewed-on: http://review.coreboot.org/7002
Tested-by: build bot (Jenkins)
Reviewed-by: Patrick Georgi <patrick@georgi-clan.de>
diff --git a/payloads/libpayload/drivers/usb/xhci_rh.c b/payloads/libpayload/drivers/usb/xhci_rh.c
index 26bb4f9..fa118fe 100644
--- a/payloads/libpayload/drivers/usb/xhci_rh.c
+++ b/payloads/libpayload/drivers/usb/xhci_rh.c
@@ -51,7 +51,7 @@
 	xhci_t *const xhci = XHCI_INST(dev->controller);
 	volatile u32 *const portsc = &xhci->opreg->prs[port - 1].portsc;
 
-	const int changed = !!(*portsc & PORTSC_CSC);
+	const int changed = !!(*portsc & (PORTSC_CSC | PORTSC_PRC));
 	/* always clear all the status change bits */
 	*portsc = (*portsc & PORTSC_RW_MASK) | 0x00ef0000;
 	return changed;