On Mon, Aug 25, 2014 at 01:01:52PM -0600, Stephen Warren wrote:

On 08/18/2014 11:08 AM, Andrew Bresticker wrote:

[...]

quoted

+static int tegra_xusb_mbox_probe(struct platform_device *pdev)

quoted

+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res)
+		return -ENODEV;

Should devm_request_mem_region() be called here to claim the region?

quoted

+	mbox->regs = devm_ioremap_nocache(&pdev->dev, res->start,
+					  resource_size(res));
+	if (!mbox->regs)
+		return -ENOMEM;

Is _nocache required? I don't see other drivers using it. I assume there's
nothing special about the mbox registers.

Most drivers should be using devm_ioremap_resource() which will use the
_nocache variant of devm_ioremap() when appropriate. Usually the region
will not be marked cacheable (IORESOURCE_CACHEABLE) and therefore be
remapped uncached.

Thierry