On Tue, Mar 11, 2014 at 6:52 AM, Andreas Noever <andreas.noever@xxxxxxxxx> wrote: > On Tue, Mar 11, 2014 at 1:10 AM, Bjorn Helgaas <bhelgaas@xxxxxxxxxx> wrote: >> On Tue, Mar 11, 2014 at 12:10:02AM +0100, Andreas Noever wrote: >>> On Mon, Mar 10, 2014 at 9:43 PM, Bjorn Helgaas <bhelgaas@xxxxxxxxxx> wrote: >>> > On Sat, Mar 8, 2014 at 2:55 AM, Andreas Noever <andreas.noever@xxxxxxxxx> wrote: >>> >> On Sat, Mar 8, 2014 at 2:04 AM, Bjorn Helgaas <bhelgaas@xxxxxxxxxx> wrote: >>> > >>> >>> If we did that, INTX_DISABLE would be cleared by the first >>> >>> pci_enable_device() and pci_reenable_device() wouldn't do anything, >>> >>> leaving it cleared. The resulting state (cleared) would be the same, >>> >>> but the transitions would be gone, and maybe those are important. >>> >> Just a quick note: With pci_intx_for_msi removed no hotplug events are >>> >> ever delivered. Everything else still works though. So it is either a >>> >> problem specific to Thunderbolt bridges or maybe it just affects >>> >> hotplug (and PME?) interrupts. >>> > >>> > Interesting. This is on a MacBook, isn't it? If you have Mac OS on >>> > it, is there a way you can do the equivalent of lspci on it? I'm >>> > curious about whether it sets INTx_DISABLE when it enables MSI. >>> >>> lspci -vv and lspci -vv -xxxx attached (yes, someone made a port). >>> >>> It looks like Mac OS sets DisINTx for all devices that have MSI >>> enabled. The only exception is the Thunderbolt controller (no >>> idea...). But the hotplug bridges all have DisINTx+. >> >> OK, thanks. I don't know what to make of that. >> >> Here's a possible patch; can you try it out? >> >> >> PCI: Do not enable INTx in pci_reenable_device() >> >> From: Bjorn Helgaas <bhelgaas@xxxxxxxxxx> >> >> Previously we cleared the Interrupt Disable bit in do_pci_enable_device(), >> which is used by both pci_enable_device() and pci_reenable_device(). But >> we use pci_reenable_device() after the driver may have enabled MSI or >> MSI-X, and we *set* Interrupt Disable as part of enabling MSI/MSI-X. >> >> The pciehp hot-plug path uses pci_reenable_device() on the hotplug bridge, >> and clearing its Interrupt Disable bit makes its hotplug event-reporting >> MSI stop working. >> >> Fixes: 1f42db786b14 PCI: Enable INTx if BIOS left them disabled >> Link: https://bugzilla.kernel.org/show_bug.cgi?id=71691 >> Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx> >> --- >> drivers/pci/pci.c | 3 +++ >> 1 file changed, 3 insertions(+) >> >> diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c >> index 8dc3e701ec57..79fc89c6c3f3 100644 >> --- a/drivers/pci/pci.c >> +++ b/drivers/pci/pci.c >> @@ -1192,6 +1192,9 @@ static int do_pci_enable_device(struct pci_dev *dev, int bars) >> return err; >> pci_fixup_device(pci_fixup_enable, dev); >> >> + if (dev->msi_enabled || dev->msix_enabled) >> + return 0; >> + >> pci_read_config_byte(dev, PCI_INTERRUPT_PIN, &pin); >> if (pin) { >> pci_read_config_word(dev, PCI_COMMAND, &cmd); > > That fixes it. Thanks for testing this, Andreas. I merged it and it's in Linus' tree now. Would you mind booting with "pci=earlydump" sometime and attaching the dmesg to the bugzilla? Your lspci output shows that INTx_DISABLE is set, and I'm curious about whether it was set by the BIOS or by Mac OS. Bjorn -- 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
