On 02/21/2014 04:42 PM, Felipe Balbi wrote: > 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); I have read it just not sure if IORESOURCE_CACHEABLE is setup by default or not. If yes, then you have to setup res->flags in your driver and have to check it. Thanks, Michal -- Michal Simek, Ing. (M.Eng), OpenPGP -> KeyID: FE3D1F91 w: www.monstr.eu p: +42-0-721842854 Maintainer of Linux kernel - Microblaze cpu - http://www.monstr.eu/fdt/ Maintainer of Linux kernel - Xilinx Zynq ARM architecture Microblaze U-BOOT custodian and responsible for u-boot arm zynq platform
Attachment:
signature.asc
Description: OpenPGP digital signature