On Tue, 2012-02-07 at 14:13 -0800, Sarah Sharp wrote: > On Tue, Feb 07, 2012 at 09:27:43AM -0800, Sarah Sharp wrote: > > I'm trying to track down an oops on my for-usb-linus queue that could > > either be related to Alex's original MSI work around patch, or the patch > > Oliver posted for working around PCI MMIO not being enabled fast enough. > > I don't want to review this MSI improvement patch until I'm sure the > > original MSI work around patch is stable. > > > > Alex, please give me time to debug bug fixes for 3.3 before pushing on > > features for 3.4. > > Alex, your original MSI enabling patch simply does not work. The xHCI > PCI driver was marked as const and the xHCI PCI probe function oopsed as > soon as it tried to add HCD_MSI_FIRST to driver->flags. Please test all > the patches in your patchsets individually to make sure they don't cause > bugs, as this will break git-bisect. It's especially troublesome to not > test a patch I've said will be needed for stable, since we really try > not to break stable. </grumpy maintainer rant> I am sorry for bring trouble on the patch. But all my patches were tested with possible USB3 HCD in our site, include a NEC device and the BIOS broken Intel panther point HCD. [ 3.772513] xhci_hcd 0000:00:14.0: can't derive routing for PCI INT A [ 3.772515] xhci_hcd 0000:00:14.0: PCI INT A: no GSI [ 3.772552] xhci_hcd 0000:00:14.0: setting latency timer to 64 [ 3.772593] xhci_hcd 0000:00:14.0: irq 45 for MSI/MSI-X [ 3.772602] xhci_hcd 0000:00:14.0: xHCI Host Controller [ 3.772639] xhci_hcd 0000:00:14.0: new USB bus registered, assigned bus number 1 Maybe some kernel configuration related with this oops? > > The oops brings up an interesting point. I think the reason the xHCI > PCI driver structure is marked as const is because it's shared across > all xHCI hosts in the system. Even if you remove the const keyword, you > could be modifying the flags while another xHCI host controller is being > initialized. > > I think PCI probe isn't run in parallel, but you could still have the > case where the Intel Panther Point xHCI PCI probe runs first, > HCD_MSI_FIRST gets added to the hcd driver flags, and then the PCI probe > runs for a Fresco Logic add-in card that doesn't handle MSI, and the USB > core doesn't attempt to allocate the legacy IRQ because HCD_MSI_FIRST is > set. Then the Fresco Logic host controller will be left with no > interrupt. Yes, you are right here. So, the first patch naturally have this problem. But my latest patch: enable MSI in usb-core won't the problem. Because it direct skip the Fresco Card for MSI, not get help from flags. So, let's drop the previous 2 patches and using this latest one? > > > Alan, is the hc_driver structure (xhci_pci_hc_driver) shared across all > xHCI PCI hosts in the system? > > Sarah Sharp -- 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
