On 5/21/2019 10:17 PM, Vidya Sagar wrote:
On 5/21/2019 3:57 PM, Thierry Reding wrote:
On Fri, May 17, 2019 at 06:08:33PM +0530, Vidya Sagar wrote:
Tegra194 rootports don't generate MSI interrupts for PME events and hence
MSI needs to be disabled for them to avoid root ports service drivers
registering their respective ISRs with MSI interrupt.
Signed-off-by: Vidya Sagar <vidyas@xxxxxxxxxx>
---
Changes since [v6]:
* This is a new patch
drivers/pci/quirks.c | 14 ++++++++++++++
1 file changed, 14 insertions(+)
diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
index 0f16acc323c6..28f9a0380df5 100644
--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c
@@ -2592,6 +2592,20 @@ DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_NVIDIA,
PCI_DEVICE_ID_NVIDIA_NVENET_15,
nvenet_msi_disable);
+/*
+ * Tegra194's PCIe root ports don't generate MSI interrupts for PME events
+ * instead legacy interrupts are generated. Hence, to avoid service drivers
+ * registering their respective ISRs for MSIs, need to disable MSI interrupts
+ * for root ports.
+ */
+static void disable_tegra194_rp_msi(struct pci_dev *dev)
+{
+ dev->no_msi = 1;
+}
+DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_NVIDIA, 0x1ad0, disable_tegra194_rp_msi);
+DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_NVIDIA, 0x1ad1, disable_tegra194_rp_msi);
+DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_NVIDIA, 0x1ad2, disable_tegra194_rp_msi);
+
Later functions in this file seem to use a more consistent naming
pattern, according to which the name for this would become:
pci_quirk_nvidia_tegra194_disable_rp_msi
Might be worth considering making this consistent.
This could also be moved to the DWC driver to restrict this to where it
is needed. In either case, this seems like a good solution, so:
Reviewed-by: Thierry Reding <treding@xxxxxxxxxx>
Ok. I'll move it to DWC driver along with name change for the quirk API.
I see that if quirk macros and API are present in pcie-tegra194.c file and driver is built
as a module, quirk API is not getting invoked by the system, whereas it gets invoked if driver
is built into kernel. Is this behavior expected? I think it is because of quirk API symbol
not available as part of global quirk symbol table when driver is built as a module?
for now, I'm going to keep quirk macros and API in pci/quirks.c file itself.
