Re: [PATCH v6 6/6] pci: Add support for creating a generic host_bridge from device tree

On Wednesday 05 March 2014, Liviu Dudau wrote:

• pr_debug("Parsing ranges property...\n");
• for_each_of_pci_range(&parser, &range) {

• /* Read next ranges element */
  

• pr_debug("pci_space: 0x%08x pci_addr:0x%016llx ",
  

• 		range.pci_space, range.pci_addr);
  

• pr_debug("cpu_addr:0x%016llx size:0x%016llx\n",
  

• 			range.cpu_addr, range.size);
  

• /*
  

•  * If we failed translation or got a zero-sized region
  

•  * then skip this range
  

•  */
  

• if (range.cpu_addr == OF_BAD_ADDR || range.size == 0)
  

• 	continue;
  

• res = kzalloc(sizeof(struct resource), GFP_KERNEL);
  

• if (!res)
  

• 	return -ENOMEM;
  

• of_pci_range_to_resource(&range, dev, res);
  

• if (resource_type(res) == IORESOURCE_IO)
  

• 	*io_base = range.cpu_addr;
  

• pci_add_resource_offset(resources, res,
  

• 		res->start - range.pci_addr);
  

• }

As mentioned regarding the pci_register_io_range() helper, x86 would not enter the 'resource_type(res) == IORESOURCE_IO' code path, which on the one hand is fine so we can return an error from pci_register_io_range() there, but I think it will lead to io_base getting an uninitialized content.

There could also be other reasons why pci_register_io_range() fails, e.g. because the space is exhausted, and I think we should try to catch that here and skip the pci_add_resource_offset() and io_base assignment then.

Arnd