On Thu, May 28, 2015 at 07:41:12AM -0500, Bjorn Helgaas wrote: > > > > I'd like res->flags to reflect the capabilities of the hardware, not > > > whether the window is currently enabled. > > > > > Flag bits seem to be all taken. Could we use IORESOURCE_DISABLED for that > > purpose, or could that cause conflicts elsewhere ? > > Yes, I think IORESOURCE_DISABLED would be appropriate for any I/O windows > below a host bridge that doesn't support I/O space. > I integrated Lorenzo's patch and tried to get this working. Problem is that the use of a resource is widely checked with "!res->flags" throughout the code. That would have to be changed to something like "(!res->flags || (res->flags & IORESOURCE_DISABLED))" whereever it is used. I tried going with "!res->flags" instead, but have not been able to get it to work realiably; it is just very difficult to distinguish if "!res->flags" means that the resource has not yet been assigned or if it means that it is not supported. The correct approach, in my opinion, would be to go with IORESOURCE_DISABLED and make the necessary changes whereever needed. Effectively this means to replace the "!res->flags" check with something like pci_res_used() [ pick your preferred name ] and define it as #define pci_res_used(res) ((res)->flags && !((res)->flags & IORESOURCE_DISABLED)) Is that the right direction ? Thanks, Guenter -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
