From: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
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://bugzilla.kernel.org/show_bug.cgi?id=215690
Link: https://lore.kernel.org/all/PxIByDyBRcsbpcmVhGSNDFAoUcMmb78ctXCkw6fbpx25TGlCHvA6SJjjFkNr1FfQZMntYPTNyvEnblxzAZ8a6jP9ddLpKeCN6Chi_2FuexU=@protonmail.com/
BugLink: https://lore.kernel.org/all/20200702143045.23429-1-andriy.shevchenko@xxxxxxxxxxxxxxx/
Link: https://lore.kernel.org/r/20220314101448.90074-1-andriy.shevchenko@xxxxxxxxxxxxxxx
Reported-by: Mick Lorain <micklorain@xxxxxxxxxxxxxx>
Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
---
drivers/pci/quirks.c | 12 ++++++++++++
1 file changed, 12 insertions(+)
diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
index d2dd6a6cda60..5f46fed01e6c 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;
--
2.25.1
