On Sat, Mar 07, 2009 at 10:38:45AM +0800, Greg KH wrote: > On Fri, Mar 06, 2009 at 01:08:10PM -0700, Matthew Wilcox wrote: > > On Fri, Feb 20, 2009 at 02:54:42PM +0800, Yu Zhao wrote: > > > + list_for_each_entry(pdev, &dev->bus->devices, bus_list) > > > + if (pdev->sriov) > > > + break; > > > + if (list_empty(&dev->bus->devices) || !pdev->sriov) > > > + pdev = NULL; > > > + ctrl = 0; > > > + if (!pdev && pci_ari_enabled(dev->bus)) > > > + ctrl |= PCI_SRIOV_CTRL_ARI; > > > + > > > > I don't like this loop. At the end of a list_for_each_entry() loop, > > pdev will not be pointing at a pci_device, it'll be pointing to some > > offset from &dev->bus->devices. So checking pdev->sriov at this point > > is really, really bad. I would prefer to see something like this: > > > > ctrl = 0; > > list_for_each_entry(pdev, &dev->bus->devices, bus_list) { > > if (pdev->sriov) > > goto ari_enabled; > > } > > > > if (pci_ari_enabled(dev->bus)) > > ctrl = PCI_SRIOV_CTRL_ARI; > > ari_enabled: > > pci_write_config_word(dev, pos + PCI_SRIOV_CTRL, ctrl); > > No, please use bus_for_each_dev() instead, or bus_find_device(), don't > walk the bus list by hand. I'm kind of surprised that even builds. Hm, > in looking at the 2.6.29-rc kernels, I notice it will not even build at > all, you are now forced to use those functions, which is good. The devices haven't been added at this time, so we can't use bus_for_each_dev(). I guess that's why the `bus->devices' exists, and actually pci_bus_add_devices() walks the bus list same way to retrieve the devices and add them. Thanks, Yu -- 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