usb/xhci: ignore xhci version while checking for the link quirk

instead of reading the xhci interface version each time _even_ if the
quirk is not required, simply check if the quirk flag is set. This flag
is only set of the module parameter is set and here is where I moved the
version check to.
Signed-off-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

drivers/usb/host/xhci.c

@@ -316,7 +316,7 @@ int xhci_init(struct usb_hcd *hcd)
 
 	xhci_dbg(xhci, "xhci_init\n");
 	spin_lock_init(&xhci->lock);
-	if (link_quirk) {
+	if (xhci->hci_version == 0x95 && link_quirk) {
 		xhci_dbg(xhci, "QUIRK: Not clearing Link TRB chain bits.\n");
 		xhci->quirks |= XHCI_LINK_TRB_QUIRK;
 	} else {

drivers/usb/host/xhci.h

@@ -1526,9 +1526,7 @@ static inline void xhci_write_64(struct xhci_hcd *xhci,
 
 static inline int xhci_link_trb_quirk(struct xhci_hcd *xhci)
 {
-	u32 temp = xhci_readl(xhci, &xhci->cap_regs->hc_capbase);
-	return ((HC_VERSION(temp) == 0x95) &&
-			(xhci->quirks & XHCI_LINK_TRB_QUIRK));
+	return xhci->quirks & XHCI_LINK_TRB_QUIRK;
 }
 
 /* xHCI debugging */