From: Bjorn Helgaas bhelgaas@google.com
[ Upstream commit 63cd736f449445edcd7f0bcc7d84453e9beec0aa ]
Some ATI SB600 USB adapters advertise MSI, but if INTx is disabled by setting PCI_COMMAND_INTX_DISABLE, MSI doesn't work either. The PCI/PCIe specs do not require software to set PCI_COMMAND_INTX_DISABLE when enabling MSI, but Linux has done that for many years.
Mick reported that 306c54d0edb6 ("usb: hcd: Try MSI interrupts on PCI devices") broke these devices. Prior to 306c54d0edb6, they used INTx. Starting with 306c54d0edb6, they use MSI, and and the fact that Linux sets PCI_COMMAND_INTX_DISABLE means both INTx and MSI are disabled on these devices.
Avoid this SB600 defect by disabling MSI so we use INTx as before.
Fixes: 306c54d0edb6 ("usb: hcd: Try MSI interrupts on PCI devices") Link: https://lore.kernel.org/r/20220321183446.1108325-1-helgaas@kernel.org Link: https://bugzilla.kernel.org/show_bug.cgi?id=215690 Link: https://lore.kernel.org/all/PxIByDyBRcsbpcmVhGSNDFAoUcMmb78ctXCkw6fbpx25TGlC... Link: https://lore.kernel.org/r/20220314101448.90074-1-andriy.shevchenko@linux.int... BugLink: https://lore.kernel.org/all/20200702143045.23429-1-andriy.shevchenko@linux.i... Reported-by: Mick Lorain micklorain@protonmail.com Signed-off-by: Bjorn Helgaas bhelgaas@google.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/pci/quirks.c | 12 ++++++++++++ 1 file changed, 12 insertions(+)
diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c index 65f7f6b0576c..da829274fc66 100644 --- a/drivers/pci/quirks.c +++ b/drivers/pci/quirks.c @@ -1811,6 +1811,18 @@ static void quirk_alder_ioapic(struct pci_dev *pdev) DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_EESSC, quirk_alder_ioapic); #endif
+static void quirk_no_msi(struct pci_dev *dev) +{ + pci_info(dev, "avoiding MSI to work around a hardware defect\n"); + dev->no_msi = 1; +} +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_ATI, 0x4386, quirk_no_msi); +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_ATI, 0x4387, quirk_no_msi); +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_ATI, 0x4388, quirk_no_msi); +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_ATI, 0x4389, quirk_no_msi); +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_ATI, 0x438a, quirk_no_msi); +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_ATI, 0x438b, quirk_no_msi); + static void quirk_pcie_mch(struct pci_dev *pdev) { pdev->no_msi = 1;