[PATCH -next v2 3/3] thunderbolt: Add quirk to reset host interface for AMD USB4 routers

[Basavaraj Natikar <Basavaraj.Natikar@amd.com>]

Affected AMD USB4 host routers hang a TX ring when a DMA HopID is
programmed again after the DMA paths are torn down without an intervening
host interface reset.

Hence, set QUIRK_RESET_DMA_ON_REUSE for these routers so a used DMA HopID
is not reprogrammed until the host interface has been reset. The reset
waits for all DMA rings to stop, leaving unrelated active tunnels
undisturbed.

Suggested-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Co-developed-by: Sanath S <Sanath.S@amd.com>
Signed-off-by: Sanath S <Sanath.S@amd.com>
Signed-off-by: Basavaraj Natikar <Basavaraj.Natikar@amd.com>
---
 drivers/thunderbolt/pci.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/thunderbolt/pci.c b/drivers/thunderbolt/pci.c
index e40d4d6af071..b60b0d136821 100644
--- a/drivers/thunderbolt/pci.c
+++ b/drivers/thunderbolt/pci.c
@@ -77,11 +77,11 @@ static void nhi_pci_check_quirks(struct tb_nhi_pci *nhi_pci)
 		case PCI_DEVICE_ID_AMD_1AH_M70H_NHI0:
 		case PCI_DEVICE_ID_AMD_1AH_M70H_NHI1:
 			/*
-			 * These AMD hosts may hang the Tx ring when the
-			 * DMA paths are torn down so they need the host
-			 * interface reset after each teardown.
+			 * These hosts may hang the Tx ring if its HopID is
+			 * programmed again without a host interface reset
+			 * in between.
 			 */
-			nhi->quirks |= QUIRK_RESET_DMA_ON_TEARDOWN;
+			nhi->quirks |= QUIRK_RESET_DMA_ON_REUSE;
 			break;
 		}
 	}
-- 
2.34.1