On Tue, Apr 26, 2011 at 05:25:00PM -0600, Bjorn Helgaas wrote: > [Sorry this isn't threaded correctly; I recently changed jobs and this > fell in the gap between.] > > I'm uneasy about release_child_resources(). This patch doesn't add > it, but it does add another use of it. > > What makes it safe for us to blindly release child resources? If we > start with something like this: > > f2500000-f25fffff : PCI Bus 0000:0d > f2500000-f25000ff : 0000:0d:00.0 > f2500000-f25000ff : mmc0 > > and we call release_child_resources() on the top-level bridge window > (f2500000-f25fffff), I think we will also release the 0000:0d:00.0 and > mmc resources. This might not be a problem at boot-time, when the > driver won't have claimed the device yet, but often we want to shuffle > resources to make a hot-plugged device work, and then we do have to > worry about other drivers. > > It seems like we need to check whether a driver is bound to a device, > and if so, leave its resources alone. I didn't see anything like > that, but maybe I missed it. But pci_assign_unassigned_resources() is called only during boot-time, before any resources are assigned to any drivers. right? If yes, then this patch should not cause the issue that you are concerned about. RP > 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
