On Wed, 27 May 2009 12:41:44 -0700 Gary Hade <garyhade@xxxxxxxxxx> wrote: > On Thu, May 21, 2009 at 09:37:37AM -0700, Gary Hade wrote: > > On Thu, May 21, 2009 at 08:46:17AM -0600, Bjorn Helgaas wrote: > > > On Wednesday 20 May 2009 5:49:10 pm Jesse Barnes wrote: > > > > On Fri, 8 May 2009 16:40:10 -0600 > > > > Bjorn Helgaas <bjorn.helgaas@xxxxxx> wrote: > > > > > Did anything happen with this? > > > > > > > > > > The longer we wait to make "use_crs" the default, the harder > > > > > it will be, so I'd like to push ahead. > > > > > > > > Here's a patch to make CRS the default. If it looks ok I can > > > > push it into my linux-next branch. I'm all for using reliable > > > > data from the BIOS. I guess we'll find out fairly quickly if > > > > this stuff isn't... > > > > > > Thanks for following up on this, Jesse. It was on my to-do list > > > for yesterday, but I didn't get to it. > > > > > > Yinghai mentioned a specific box where we might have trouble, but > > > we never got enough details to really debug it. So I think we > > > might as well give it a shot and fine-tune it as we need to. > > > > I just remembered that Andrew Morton once raised some concerns > > related to the number of _CRS returned resources exceeding the > > fixed resource array size -> http://lkml.org/lkml/2007/11/1/49 > > > > I believe PCI_BUS_NUM_RESOURCES was later increased but if > > that increase was insufficient to cover all systems that the > > code will now be exposed to, it seems like the "And should we > > really be silently ignoring this problem? Should we at least > > report it?" comment that was not addressed could become relevent. > > Not only do we not warn, if we did warn based on the current > 'if (info->res_num >= PCI_BUS_NUM_RESOURCES)' > resource array overrun avoidance criteria it would be incorrect > for a root bus that is connected to a subordinate bus with a > transparent bridge. We need to avoid the last 3 slots of the > resource array since they do not get mapped to a transparent > bridge connected subordinate bus. I believe the below patch > addresses these issues. > > With PCI_BUS_NUM_RESOURCES currently at 16 we still have space > to accomodate 13 _CRS returned resource descriptors which will > hopefully be sufficient. Ok, applied the patch (with Yinghai's suggested name change) to my linux-next branch. We'll see now it goes and revert it if there's trouble. -- Jesse Barnes, Intel Open Source Technology Center -- 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
