On Fri, Oct 28, 2016 at 06:58:17PM -0400, Keith Busch wrote:
> There is no need to disable MSIx interrupts or write message data on a
> device that isn't present. This patch checks the device removed state
> prior to executing device shutdown operations so that tear down on
> removed devices completes quicker.
>
> Signed-off-by: Keith Busch <keith.busch@xxxxxxxxx>
> Cc: Lukas Wunner <lukas@xxxxxxxxx>
> ---
> drivers/pci/msi.c | 7 ++++++-
> 1 file changed, 6 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
> index bfdd074..9249ec1 100644
> --- a/drivers/pci/msi.c
> +++ b/drivers/pci/msi.c
> @@ -317,7 +317,7 @@ void __pci_write_msi_msg(struct msi_desc *entry, struct msi_msg *msg)
> {
> struct pci_dev *dev = msi_desc_to_pci_dev(entry);
>
> - if (dev->current_state != PCI_D0) {
> + if (dev->current_state != PCI_D0 || dev->is_removed) {
> /* Don't touch the hardware now */
> } else if (entry->msi_attrib.is_msix) {
> void __iomem *base = pci_msix_desc_addr(entry);
> @@ -1017,6 +1017,11 @@ void pci_msix_shutdown(struct pci_dev *dev)
> if (!pci_msi_enable || !dev || !dev->msix_enabled)
> return;
>
> + if (dev->is_removed) {
> + dev->msix_enabled = 0;
> + return;
> + }
> +
> /* Return the device with MSI-X masked as initial states */
> for_each_pci_msi_entry(entry, dev) {
> /* Keep cached states to be restored */
Do we need the same thing in pci_msi_shutdown()?
It's too bad we have the data structure maintenance stuff all
intermingled with the hardware-touching code. I don't know how they
could really be disentangled, but it feels a little ad hoc to sprinkle
is_removed checks in random places where we observe problems.
Bjorn
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