3 files changed, 19 insertions, 7 deletions

diff --git a/sys/dev/usb/ehci.c b/sys/dev/usb/ehci.c
index 5324c5e01422..a66ac97992ab 100644
--- a/sys/dev/usb/ehci.c
+++ b/sys/dev/usb/ehci.c
@@ -2710,11 +2710,11 @@ ehci_timeout_task(void *addr)
 }
 
 /*
- * Some EHCI chips from VIA seem to trigger interrupts before writing back the
- * qTD status, or miss signalling occasionally under heavy load.  If the host
- * machine is too fast, we we can miss transaction completion - when we scan
- * the active list the transaction still seems to be active.  This generally
- * exhibits itself as a umass stall that never recovers.
+ * Some EHCI chips from VIA / ATI seem to trigger interrupts before writing
+ * back the qTD status, or miss signalling occasionally under heavy load.
+ * If the host machine is too fast, we can miss transaction completion - when
+ * we scan the active list the transaction still seems to be active. This
+ * generally exhibits itself as a umass stall that never recovers.
  *
  * We work around this behaviour by setting up this callback after any softintr
  * that completes with transactions still pending, giving us another chance to
diff --git a/sys/dev/usb/ehci_pci.c b/sys/dev/usb/ehci_pci.c
index b03d94cd90e6..204fad084514 100644
--- a/sys/dev/usb/ehci_pci.c
+++ b/sys/dev/usb/ehci_pci.c
@@ -335,6 +335,9 @@ ehci_pci_attach(device_t self)
 	case PCI_EHCI_VENDORID_APPLE:
 		sprintf(sc->sc_vendor, "Apple");
 		break;
+	case PCI_EHCI_VENDORID_ATI:
+		sprintf(sc->sc_vendor, "ATI");
+		break;
 	case PCI_EHCI_VENDORID_CMDTECH:
 		sprintf(sc->sc_vendor, "CMDTECH");
 		break;
@@ -374,8 +377,17 @@ ehci_pci_attach(device_t self)
 	}
 
 	/* Enable workaround for dropped interrupts as required */
-	if (pci_get_vendor(self) == PCI_EHCI_VENDORID_VIA)
+	switch (pci_get_vendor(self)) {
+	case PCI_EHCI_VENDORID_ATI:
+	case PCI_EHCI_VENDORID_VIA:
 		sc->sc_flags |= EHCI_SCFLG_LOSTINTRBUG;
+		if (bootverbose)
+			device_printf(self,
+			    "Dropped interrupts workaround enabled\n");
+		break;
+	default:
+		break;
+	}
 
 	/*
 	 * Find companion controllers.  According to the spec they always
diff --git a/sys/dev/usb/ehcivar.h b/sys/dev/usb/ehcivar.h
index e1b852d00344..fb66ae7d5ed3 100644
--- a/sys/dev/usb/ehcivar.h
+++ b/sys/dev/usb/ehcivar.h
@@ -94,7 +94,7 @@ struct ehci_soft_islot {
 #define EHCI_COMPANION_MAX 8
 
 #define EHCI_SCFLG_DONEINIT	0x0001	/* ehci_init() has been called. */
-#define EHCI_SCFLG_LOSTINTRBUG	0x0002	/* workaround for VIA chipsets */
+#define EHCI_SCFLG_LOSTINTRBUG	0x0002	/* workaround for VIA / ATI chipsets */
 
 typedef struct ehci_softc {
 	struct usbd_bus sc_bus;		/* base device */