usb: gadget: atmel_usba_udc: Expose correct device speed

Following changes that appeared in lk 4.0.0, the gadget udc driver for
some ARM based Atmel SoCs (e.g. at91sam9x5 and sama5d3 families)
incorrectly deduced full-speed USB link speed even when the hardware
had negotiated a high-speed link. The fix is to make sure that the
UDPHS Interrupt Enable Register value does not mask the SPEED bit
in the Interrupt Status Register.

For a mass storage gadget this problem lead to failures when the host
had a USB 3 port with the xhci_hcd driver. If the host was a USB 2
port using the ehci_hcd driver then the mass storage gadget worked
(but probably at a lower speed than it should have).

Signed-off-by: Douglas Gilbert <dgilbert@interlog.com>
Reviewed-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Cc: <stable@vger.kernel.org> #4.0+
Fixes: 9870d895ad87 ("usb: atmel_usba_udc: Mask status with enabled irqs")
Signed-off-by: Felipe Balbi <balbi@ti.com>

drivers/usb/gadget/udc/atmel_usba_udc.c

@@ -1633,7 +1633,7 @@ static irqreturn_t usba_udc_irq(int irq, void *devid)
 	spin_lock(&udc->lock);
 
 	int_enb = usba_int_enb_get(udc);
-	status = usba_readl(udc, INT_STA) & int_enb;
+	status = usba_readl(udc, INT_STA) & (int_enb | USBA_HIGH_SPEED);
 	DBG(DBG_INT, "irq, status=%#08x\n", status);
 
 	if (status & USBA_DET_SUSPEND) {