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authorAlex Williamson <alex.williamson@redhat.com>2019-04-22 16:43:30 -0600
committerBjorn Helgaas <bhelgaas@google.com>2019-05-01 15:34:01 -0500
commit15d2aba7c602cd9005b20ff011b670547b3882c4 (patch)
treed570281e05772f02049eb37d8c82d97c63bfd497
parentd5bc73f34cc97c4b4b9202cc93182c2515076edf (diff)
PCI/portdrv: Use shared MSI/MSI-X vector for Bandwidth Management
The Interrupt Message Number in the PCIe Capabilities register (PCIe r4.0, sec 7.5.3.2) indicates which MSI/MSI-X vector is shared by interrupts related to the PCIe Capability, including Link Bandwidth Management and Link Autonomous Bandwidth Interrupts (Link Control, 7.5.3.7), Command Completed and Hot-Plug Interrupts (Slot Control, 7.5.3.10), and the PME Interrupt (Root Control, 7.5.3.12). pcie_message_numbers() checked whether we want to enable PME or Hot-Plug interrupts but neglected to check for Link Bandwidth Management, so if we only wanted the Bandwidth Management interrupts, it decided we didn't need any vectors at all. Then pcie_port_enable_irq_vec() tried to reallocate zero vectors, which failed, resulting in fallback to INTx. On some systems, e.g., an X79-based workstation, that INTx seems broken or not handled correctly, so we got spurious IRQ16 interrupts for Bandwidth Management events. Change pcie_message_numbers() so that if we want Link Bandwidth Management interrupts, we use the shared MSI/MSI-X vector from the PCIe Capabilities register. Fixes: e8303bb7a75c ("PCI/LINK: Report degraded links via link bandwidth notification") Link: https://lore.kernel.org/lkml/155597243666.19387.1205950870601742062.stgit@gimli.home Signed-off-by: Alex Williamson <alex.williamson@redhat.com> [bhelgaas: changelog] Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
-rw-r--r--drivers/pci/pcie/portdrv_core.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/pci/pcie/portdrv_core.c b/drivers/pci/pcie/portdrv_core.c
index 7d04f9d087a6..1b330129089f 100644
--- a/drivers/pci/pcie/portdrv_core.c
+++ b/drivers/pci/pcie/portdrv_core.c
@@ -55,7 +55,8 @@ static int pcie_message_numbers(struct pci_dev *dev, int mask,
* 7.8.2, 7.10.10, 7.31.2.
*/
- if (mask & (PCIE_PORT_SERVICE_PME | PCIE_PORT_SERVICE_HP)) {
+ if (mask & (PCIE_PORT_SERVICE_PME | PCIE_PORT_SERVICE_HP |
+ PCIE_PORT_SERVICE_BWNOTIF)) {
pcie_capability_read_word(dev, PCI_EXP_FLAGS, &reg16);
*pme = (reg16 & PCI_EXP_FLAGS_IRQ) >> 9;
nvec = *pme + 1;