[PATCH 4.4 098/132] IB/hfi1: Ensure full Gen3 speed in a Gen4 system

[Greg Kroah-Hartman]

From: James Erwin <james.erwin@xxxxxxxxx>

If an hfi1 card is inserted in a Gen4 systems, the driver will avoid the
gen3 speed bump and the card will operate at half speed.

This is because the driver avoids the gen3 speed bump when the parent bus
speed isn't identical to gen3, 8.0GT/s.  This is not compatible with gen4
and newer speeds.

Fix by relaxing the test to explicitly look for the lower capability
speeds which inherently allows for gen4 and all future speeds.

Fixes: 7724105686e7 ("IB/hfi1: add driver files")
Link: https://lore.kernel.org/r/20191101192059.106248.1699.stgit@xxxxxxxxxxxxxxxxxxxx
Cc: <stable@xxxxxxxxxxxxxxx>
Reviewed-by: Dennis Dalessandro <dennis.dalessandro@xxxxxxxxx>
Reviewed-by: Kaike Wan <kaike.wan@xxxxxxxxx>
Signed-off-by: James Erwin <james.erwin@xxxxxxxxx>
Signed-off-by: Mike Marciniszyn <mike.marciniszyn@xxxxxxxxx>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@xxxxxxxxx>
Signed-off-by: Jason Gunthorpe <jgg@xxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/staging/rdma/hfi1/pcie.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/staging/rdma/hfi1/pcie.c b/drivers/staging/rdma/hfi1/pcie.c
index a956044459a2b..ea4df848d8405 100644
--- a/drivers/staging/rdma/hfi1/pcie.c
+++ b/drivers/staging/rdma/hfi1/pcie.c
@@ -389,7 +389,8 @@ int pcie_speeds(struct hfi1_devdata *dd)
 	/*
 	 * bus->max_bus_speed is set from the bridge's linkcap Max Link Speed
 	 */
-	if (dd->pcidev->bus->max_bus_speed != PCIE_SPEED_8_0GT) {
+	if (dd->pcidev->bus->max_bus_speed == PCIE_SPEED_2_5GT ||
+	     dd->pcidev->bus->max_bus_speed == PCIE_SPEED_5_0GT) {
 		dd_dev_info(dd, "Parent PCIe bridge does not support Gen3\n");
 		dd->link_gen3_capable = 0;
 	}
-- 
2.20.1