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| author | Alex Williamson <alex.williamson@redhat.com> | 2019-04-23 00:43:30 +0200 |
|---|---|---|
| committer | Bjorn Helgaas <bhelgaas@google.com> | 2019-05-01 22:34:01 +0200 |
| commit | 15d2aba7c602cd9005b20ff011b670547b3882c4 (patch) | |
| tree | d570281e05772f02049eb37d8c82d97c63bfd497 /drivers/pci | |
| parent | PCI: Fix issue with "pci=disable_acs_redir" parameter being ignored (diff) | |
| download | linux-15d2aba7c602cd9005b20ff011b670547b3882c4.tar.xz linux-15d2aba7c602cd9005b20ff011b670547b3882c4.zip | |
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>
Diffstat (limited to 'drivers/pci')
| -rw-r--r-- | drivers/pci/pcie/portdrv_core.c | 3 |
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, ®16); *pme = (reg16 & PCI_EXP_FLAGS_IRQ) >> 9; nvec = *pme + 1; |