On Tue, 2008-08-05 at 10:38 -0700, Jesse Barnes wrote: > On Tuesday, August 05, 2008 9:36 am James Bottomley wrote: > > On Mon, 2008-08-04 at 14:55 +0100, David Vrabel wrote: > > > Moore, Eric wrote: > > > > Thanks, I will try this out. However I thought I saw lost > > > > interrupts occurring randomly, meaning it was not necessarily the > > > > first config page access. I'm back in the office on 8/11, I will > > > > test it out then and provide feedback. > > > > > > Is this using MSI on a device without per-vector mask bits? If so, then > > > this patch may help. > > > > > > http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit > > >;h=ce6fce4295ba727b36fdc73040e444bd1aae64cd > > > > We don't really know what the problem is. MSI interrupts get lost on > > older motherboards (the ones most likely to contain a 1030). Why is > > anybody's guess although the clever money is on the motherboard bridge > > having issues. > > David just got us to fix an MSI masking bug recently, which could be related. > > The issue is that the PCI & interrupt handling code was disabling MSI during > interrupt handling, which could end up causing missed interrupts. When MSI > is disabled, devices can still generate interrupts, but they'll go out the > interrupt line instead, so unless your IRQ handler is also registered with > that IRQ number, you'll probably lose them. > > As of the last PCI upstream merge, we work around this issue by never masking > MSI interrupts unless the device supports the MSI mask bit (as opposed to > just the big hammer enable/disable flag). True, but this is orthogonal. I'm trying to put together a diagnosing tool. Once we know there's a problem and who has it, then we can try seeing if patches like this fix it. James -- 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
