On Mon, Apr 29, 2013 at 02:23:50PM -0700, Sarah Sharp wrote: > On Mon, Apr 29, 2013 at 11:21:42AM -0700, Greg Kroah-Hartman wrote: > > On Mon, Apr 29, 2013 at 11:15:50AM -0700, Bjorn Helgaas wrote: > > > On Mon, Apr 29, 2013 at 08:19:10AM -0700, Yinghai Lu wrote: > > > > On Mon, Apr 29, 2013 at 3:04 AM, Gu Zheng <guz.fnst@xxxxxxxxxxxxxx> wrote: > > > > > On 04/27/2013 05:01 AM, Yinghai Lu wrote: > > > > >> On Fri, Apr 26, 2013 at 1:53 PM, Bjorn Helgaas <bhelgaas@xxxxxxxxxx> wrote: > > > > >>> > > > > >>> You can't be serious. This is a disgusting mess. Checking a list > > > > >>> pointer for LIST_POISON1? As far as I'm concerned, this is a waste of > > > > >>> my time. > > > > > > > > looks like xhci is using that LIST_POISON1 ... > > > > > > > Maybe my allergic reaction to your use of LIST_POISON1 is unjustified, > > > but I am dubious about the idea that xhci was the only place that needed > > > it before now, and we just happened to find one more place in PCI that > > > needs it. That doesn't make sense because good design patterns are used > > > many times, not just once or twice. > > > > > > I thought the whole point of the get/put scheme was that if we had a > > > pointer to a correctly reference-counted object, we didn't need to check > > > whether the object was still valid because the object remains valid until > > > all the references are released. > > > > You are correct, you shouldn't have to worry about that. If you have to > > do something like the LIST_POISON test, something is really wrong. > > All right, I'll take a look at the xHCI code. From a brief glance, both > places that use LIST_POISON are handling a timed-out command. The > command handling in xHCI needs to get completely reworked anyway, due to > other race conditions. > > Were you suggesting I use the get/put scheme in the xHCI driver, or was > that for Yinghai? I thought for Yinghai, but really, no code should have to check that type of thing, so if the xhci driver is, it shouldn't :) thanks, greg k-h -- 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
