From: KarimAllah Ahmed Date: Wed, 17 Jan 2018 18:30:29 +0000 (+0100) Subject: PCI/IOV: Skip INTx config reads for VFs X-Git-Tag: v4.17-rc1~93^2~13^2~3 X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=be20f6b063f51cd77d071b803ee24f23200dc559;p=linux.git PCI/IOV: Skip INTx config reads for VFs Per PCIe r4.0, sec 9.2.1.4, VFs can not implement INTX, and their Interrupt Line and Interrupt Pin registers must be RO Zero. Some devices have thousands of VFs, so skip reading the registers as an optimization. Signed-off-by: KarimAllah Ahmed Signed-off-by: Jan H. Schönherr [bhelgaas: changelog, comment] Signed-off-by: Bjorn Helgaas --- diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index 489660d0d384..a1cddca37793 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -1230,6 +1230,13 @@ static void pci_read_irq(struct pci_dev *dev) { unsigned char irq; + /* VFs are not allowed to use INTx, so skip the config reads */ + if (dev->is_virtfn) { + dev->pin = 0; + dev->irq = 0; + return; + } + pci_read_config_byte(dev, PCI_INTERRUPT_PIN, &irq); dev->pin = irq; if (irq)