On Thu, May 24, 2018 at 09:31:07PM +0300, Mika Westerberg wrote: > On Thu, May 24, 2018 at 01:08:37PM -0500, Bjorn Helgaas wrote: > > Why do we even need to bother checking "bridge" for NULL? > > > > I don't believe in gratuitously checking for NULL because it can hide > > higher-level bugs, i.e., if this is called with a NULL pointer, that's > > likely a bug in the caller, and if we silently return "false", we'll > > never discover the caller's bug. > > But it also makes caller's life easier because now you don't need to do > this: > > if (bus->self && hotplug_is_native(bus->self)) > > because it is perfectly legal to call that function for host bridge. So > you do this instead > > if (hotplug_is_native(bus->self)) > > and it is not hiding a bug IMHO. True, it's not hiding a bug, but I think it is useful for readers of acpiphp_add_context() to see the NULL check there and realize that bus->self (or "pdev" in current upstream) is allowed to be NULL. That helps understand the way acpiphp works (well, I understand very little of it, but every little clue helps).
