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?