On Mon, Feb 18, 2013 at 2:09 AM, Hannes Reinecke <[email protected]> wrote: > The PCI config space reseves a byte for the interrupt line, > so irq 255 actually refers to 'not set'. > However, the 'irq' field for struct pci_dev is an integer, > so the original meaning is lost, causing the system to > assign an interrupt '255', which fails. > > So we should _not_ assign an interrupt value here, and > allow upper layers to fixup things. > > This patch make PCI devices with MSI interrupts only > (like the xhci device on certain HP laptops) work properly.
looks like the bios does not provide _PRT for device in ACPI. also according to PCI spec, BIOS *must* set interrupt line. > > Cc: Frederik Himpe <[email protected]> > Cc: Oliver Neukum <[email protected]> > Cc: David Haerdeman <[email protected]> > Cc: [email protected] > Cc: [email protected] > Signed-off-by: Hannes Reinecke <[email protected]> > > diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c > index 6186f03..a2db887f 100644 > --- a/drivers/pci/probe.c > +++ b/drivers/pci/probe.c > @@ -923,7 +923,8 @@ static void pci_read_irq(struct pci_dev *dev) > dev->pin = irq; > if (irq) > pci_read_config_byte(dev, PCI_INTERRUPT_LINE, &irq); > - dev->irq = irq; > + if (irq < 255) > + dev->irq = irq; > } > > void set_pcie_port_type(struct pci_dev *pdev) > -- > 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/ -- 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/
