Re: [PATCH RFC] usb: gadget: Add xilinx axi usb2 device support

[Felipe Balbi]

Hi,

On Fri, Feb 21, 2014 at 02:41:03PM +0100, Michal Simek wrote:
> >>> +	/* Map the registers */
> >>> +	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> >>> +	udc->base_address = devm_ioremap_nocache(&pdev->dev, res->start,
> >>> +						 resource_size(res));
> >>
> >> use devm_ioremap_resource() instead.
> > 
> > Also, res might be NULL. You should check that before dereferencing it.
> 
> yes it is necessary for both cases with devm_ioremap_nocache
> or with devm_ioremap_resource.

read the source Luke:

| void __iomem *devm_ioremap_resource(struct device *dev, struct resource *res)
| {
| 	resource_size_t size;
| 	const char *name;
| 	void __iomem *dest_ptr;
| 
| 	BUG_ON(!dev);
| 
| 	if (!res || resource_type(res) != IORESOURCE_MEM) {
            ^^^^
	    already done for you

| 		dev_err(dev, "invalid resource\n");
| 		return ERR_PTR(-EINVAL);
| 	}
| 
| 	size = resource_size(res);
| 	name = res->name ?: dev_name(dev);
| 
| 	if (!devm_request_mem_region(dev, res->start, size, name)) {
| 		dev_err(dev, "can't request region for resource %pR\n", res);
| 		return ERR_PTR(-EBUSY);
| 	}
| 
| 	if (res->flags & IORESOURCE_CACHEABLE)
| 		dest_ptr = devm_ioremap(dev, res->start, size);
| 	else
| 		dest_ptr = devm_ioremap_nocache(dev, res->start, size);
| 
| 	if (!dest_ptr) {
| 		dev_err(dev, "ioremap failed for resource %pR\n", res);
| 		devm_release_mem_region(dev, res->start, size);
| 		dest_ptr = ERR_PTR(-ENOMEM);
| 	}
| 
| 	return dest_ptr;
| }

-- 
balbi

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