On Wed, Mar 08, 2017 at 05:09:45PM +0800, Peter Xu wrote: > On Wed, Mar 08, 2017 at 10:17:09AM +0200, Marcel Apfelbaum wrote: > > [...] > > > > > I am sorry I was not clear enough: > > If a device is added after the system is up (hotplug), we cannot depend on > > the "machine_done" > > event to enable "bus master". > > This is why we have > > if (qdev_hotplug) > > pci_init_bus_master(pci_dev); > > > > The code you proposed changes the order, so this call is done *after* > > realize. > > > > My question was: What if any other device may require the bus_master_as > > at realize time (and can be hot-plugged) ? > > For example: hcd-ehci/hcd-ohci devices call pci_get_address_space() > > and caches the bus_master_as. > > Oh, I didn't notice that there are other devices that used > bus_master_as during realization. If so... Would this really work even > without hot plug? Considering that bus_master_as won't be inited until > machine done phase?
Please ignore my question... I think the answer is that these devices are only caching the pointer of bus_master_as. So it won't really use the address space before machine_done. If so, IMHO moving pci_init_bus_master() after device specific realize() is okay as well then, right? Thanks, -- peterx
