On Thu, Aug 08, 2024 at 06:05:54PM -0300, Guilherme Giácomo Simões wrote: > Bjorn Helgaas <helgaas@xxxxxxxxxx> writes: > > > > On Tue, Aug 06, 2024 at 05:54:15PM -0300, Guilherme Giácomo Simões wrote: > > > Ilpo Järvinen <ilpo.jarvinen@xxxxxxxxxxxxxxx> wrote: > > > > On Sat, 3 Aug 2024, Guilherme Giacomo Simoes wrote: > > > > > > > > > I can see that the function pci_hp_add_brigde have a int return > > > > > propagation. > > > ... > > > > > > The lack of return value checking seems to be on the list in > > > > pci_hp_add_bridge(). So perhaps the right course of action would be to > > > > handle return values correctly. > > > > > > Ok, so if the right course is for the driver to handle return value, > > > then this is a > > > task for the driver developers, because only they know what to do when > > > pci_hp_add_bridge() doesn't work correctly, right? > > > > pci_hp_add_bridge() is only for hotplug drivers, so the list of > > callers is short and completely under our control. There's plenty of > > opportunity for improving this. Beyond just the return value, all the > > callers of pci_hp_add_bridge() should be doing much of the same work > > that could potentially be factored out. > > Okay, then what the action that the drivers must be do when the add > bridge is failed? pci_hp_add_bridge() fails when there's no bus number available to assign to new hot-added devices. When that happens, there's really nothing the hotplug drivers can do to improve the situation. pci_hp_add_bridge() already logs a message for one of the failure cases. It may be that it should also log a message for the other failure case. The end result is that we can't use the hot-added devices because there's no space for them in the PCI bus number space, so we can't address them. Bjorn
