Re: [PATCH] PCI: quirk RTL8110SC INTx masking

[Bjorn Helgaas <bhelgaas@google.com>]

On Thu, May 01, 2014 at 02:36:31PM -0600, Alex Williamson wrote:
> INTx masking does not work on this device.  To see this, configure
> the network device UP on an active network, note that the interrupt
> count continues to increment for the device in /proc/interrupts.  Use
> setpci to set the PCI_COMMAND_INTX_DISABLE bit in the PCI_COMMAND
> register.  As expected, the interrupt count ceases to increment.
> However, reading the PCI_STATUS_INTERRUPT bit of the PCI_STATUS
> register does not indicate that interrupts are pending and clearing
> PCI_COMMAND_INTX_DISABLE in the PCI_COMMAND register does not allow
> the device to continue operation.
> 
> This does not affect operation of the host r8169 driver, but it does
> prevent the device from being functional when assigned to a VM, such
> as with QEMU and VFIO.  The guest driver successfully probes the
> device, but there is no traffic.  Mark INTx masking as broken,
> allowing the more restrictive APIC masking to be used instead.
> 
> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

Applied to pci/virtualization for v3.16, thanks.

> ---
>  drivers/pci/quirks.c |    8 ++++++++
>  1 file changed, 8 insertions(+)
> 
> diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
> index ea55b0f..e15a5da 100644
> --- a/drivers/pci/quirks.c
> +++ b/drivers/pci/quirks.c
> @@ -2991,6 +2991,14 @@ DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_CHELSIO, 0x0030,
>  			 quirk_broken_intx_masking);
>  DECLARE_PCI_FIXUP_HEADER(0x1814, 0x0601, /* Ralink RT2800 802.11n PCI */
>  			 quirk_broken_intx_masking);
> +/*
> + * Realtek RTL8169 PCI Gigabit Ethernet Controller (rev 10)
> + * Subsystem: Realtek RTL8169/8110 Family PCI Gigabit Ethernet NIC
> + *
> + * RTL8110SC - Fails under PCI device assignment using DisINTx masking.
> + */
> +DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_REALTEK, 0x8169,
> +			 quirk_broken_intx_masking);
>  
>  static void pci_do_fixups(struct pci_dev *dev, struct pci_fixup *f,
>  			  struct pci_fixup *end)
> 
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