[PATCH 4.19 064/109] PCI: Mark TI C667X to avoid bus reset

From: Sasha Levin
Date: Mon Jun 28 2021 - 11:03:36 EST


From: Antti Järvinen <antti.jarvinen@xxxxxxxxx>

commit b5cf198e74a91073d12839a3e2db99994a39995d upstream.

Some TI KeyStone C667X devices do not support bus/hot reset. The PCIESS
automatically disables LTSSM when Secondary Bus Reset is received and
device stops working. Prevent bus reset for these devices. With this
change, the device can be assigned to VMs with VFIO, but it will leak state
between VMs.

Reference: https://e2e.ti.com/support/processors/f/791/t/954382
Link: https://lore.kernel.org/r/20210315102606.17153-1-antti.jarvinen@xxxxxxxxx
Signed-off-by: Antti Järvinen <antti.jarvinen@xxxxxxxxx>
Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
Reviewed-by: Kishon Vijay Abraham I <kishon@xxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/pci/quirks.c | 10 ++++++++++
1 file changed, 10 insertions(+)

diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
index 70f05595da60..bc4858b056f9 100644
--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c
@@ -3483,6 +3483,16 @@ DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_ATHEROS, 0x0034, quirk_no_bus_reset);
*/
DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_CAVIUM, 0xa100, quirk_no_bus_reset);

+/*
+ * Some TI KeyStone C667X devices do not support bus/hot reset. The PCIESS
+ * automatically disables LTSSM when Secondary Bus Reset is received and
+ * the device stops working. Prevent bus reset for these devices. With
+ * this change, the device can be assigned to VMs with VFIO, but it will
+ * leak state between VMs. Reference
+ * https://e2e.ti.com/support/processors/f/791/t/954382
+ */
+DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_TI, 0xb005, quirk_no_bus_reset);
+
static void quirk_no_pm_reset(struct pci_dev *dev)
{
/*
--
2.30.2