On Wed, Dec 17, 2014 at 12:36 AM, Yijing Wang <wangyijing@xxxxxxxxxx> wrote: > On 2014/12/17 14:21, ratheesh kannoth wrote: >> On Wed, Dec 17, 2014 at 11:44 AM, Yijing Wang <wangyijing@xxxxxxxxxx> wrote: >>> Unbind won't release PCI device bar resource, resources in /proc/iomem is the >>> physical address resource(added by request_resource()), if you iounmap the bar resource, >>> it won't change anything in /proc/iomem. >> >> who is calling request_resource() ...is it enic driver ? > > PCI core interface, E.g pci_bus_assign_resources() Hi Ratheesh, There are two things going on in /proc/iomem: 1) The core should put all the hardware that responds to physical accesses in /proc/iomem. These entries should be there regardless of whether we have a driver for the device. These are used when assigning addresses to new devices, to make sure we don't assign the same address to two different devices. These entries include RAM, ACPI tables, APICs, PCI host bridges, PCI MMCONFIG regions, PCI devices, etc. It *should* also include address space consumed by other things like PNP and ACPI devices, but that is currently missing. 2) Individual drivers claim address space they use to control their device, e.g., with pci_request_regions(), ioremap(), etc. This puts an entry in /proc/iomem with the driver name on it. A device may respond to several physical address regions, and a driver need not claim all of them, and it may even claim only part of a region. So when you unbind a driver, you should see the second type of entry go away. When you actually remove a device (hot-remove or sysfs remove), you should see the first type go away as well, which means there's no longer anything that will respond to that physical address space. Bjorn -- 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
