[SeaBIOS] [PATCH 1/2] xhci: Improve port status change debugging

[Kevin O'Connor]

Report the port state on a port status change notification.  Clear the
change bits so further change notifications are delivered.

Signed-off-by: Kevin O'Connor 
---
 src/hw/usb-xhci.c | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/src/hw/usb-xhci.c b/src/hw/usb-xhci.c
index 654feba..5f44239 100644
--- a/src/hw/usb-xhci.c
+++ b/src/hw/usb-xhci.c
@@ -658,9 +658,15 @@ static void xhci_process_events(struct usb_xhci_s *xhci)
         }
         case ER_PORT_STATUS_CHANGE:
         {
-            u32 portid = (etrb->ptr_low >> 24) & 0xff;
-            dprintf(3, "%s: status change port #%d\n",
-                    __func__, portid);
+            u32 port = ((etrb->ptr_low >> 24) & 0xff) - 1;
+            // Read status, and clear port status change bits
+            u32 portsc = readl(&xhci->pr[port].portsc);
+            u32 pclear = (((portsc & ~(XHCI_PORTSC_PED|XHCI_PORTSC_PR))
+                           & ~(XHCI_PORTSC_PLS_MASK<<XHCI_PORTSC_PLS_SHIFT))
+                          | (1<<XHCI_PORTSC_PLS_SHIFT));
+            writel(&xhci->pr[port].portsc, pclear);
+
+            xhci_print_port_state(3, __func__, port, portsc);
             break;
         }
         default: