On Thu, 18 Oct 2007, David Miller wrote: > From: "Shane Huang" <[EMAIL PROTECTED]> > Date: Thu, 18 Oct 2007 18:37:59 +0800 > > > Hi Miller: > > > > Thank you for your response. > > > > The reason why MSIs of these northbridges do not work is still under > > further debug, we are NOT able to tell its hardware issue or software > > issue at this time. But enablement of them will lead to the OS > > installation failure in many distributions like openSUSE, Ubuntu etc: > > https://bugzilla.novell.com/show_bug.cgi?id=302016 > > > > So we have to disable them firstly before we find out the root cause, > > maybe they are just workarounds. > > This logic seems backwards, to me. "shoot first, ask questions later" > To me this it not how to approach this problem. > > Once you turn MSI off, there is next to no incentive to fix the > problem because users aren't running into it any longer. > > The only two devices in that bug report which should be using MSI > would be the SATA controller and the broadcom ethernet NIC. And by > the failed bootup logs provided by the user the problem is clearly > with the SATA controller.
And the same SATA controller could show up behind a different northbridge. It would be unfortunate to hit the same device bug independantly on each system and work around it by doing something that won't help the next user. > One common problem we're finding is that some devices have a hardware > bug where setting INTX_DISABLE in the PCI COMMAND register masks MSI > interrupts too. > > I mention this because the user in that report mentions that the > kernel upgrade causes the failure, and one thing we started doing not > too long ago was to set the INTX_DISABLE bit when MSI is enabled for a > device. > > So maybe this SATA controller has this problem too. It is easy to > test, simply comment out all of the pci_intx() function calls in > drivers/pci/msi.c and perform a test boot with MSI enabled. Have we gotten around to having a device quirk for this? I bet it won't be too long before we see a system where the SATA controller doesn't work with INTX disabled and the ethernet controller doesn't work with it enabled, since we've seen devices with each of these bugs. -Daniel *This .sig left intentionally blank* - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/