usb: Missing dma_mask in ehci-vt8500.c when probed from device-tree

Device-tree probed devices don't get a dev.dma_mask set. This patch
sets a default 32bit mask on arch-vt8500 when using devicetree.

Without this patch, arch-vt8500 cannot detect ehci attached devices.
Signed-off-by: Tony Prisk <linux@prisktech.co.nz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/host/ehci-vt8500.c

@@ -85,6 +85,8 @@ static const struct hc_driver vt8500_ehci_hc_driver = {
 	.clear_tt_buffer_complete	= ehci_clear_tt_buffer_complete,
 };
 
+static u64 vt8500_ehci_dma_mask = DMA_BIT_MASK(32);
+
 static int vt8500_ehci_drv_probe(struct platform_device *pdev)
 {
 	struct usb_hcd *hcd;
@@ -95,6 +97,14 @@ static int vt8500_ehci_drv_probe(struct platform_device *pdev)
 	if (usb_disabled())
 		return -ENODEV;
 
+	/*
+	 * Right now device-tree probed devices don't get dma_mask set.
+	 * Since shared usb code relies on it, set it here for now.
+	 * Once we have dma capability bindings this can go away.
+	 */
+	if (!pdev->dev.dma_mask)
+		pdev->dev.dma_mask = &vt8500_ehci_dma_mask;
+
 	if (pdev->resource[1].flags != IORESOURCE_IRQ) {
 		pr_debug("resource[1] is not IORESOURCE_IRQ");
 		return -ENOMEM;