The patch below does not apply to the 4.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From a9c3c4c597704b3a1a2b9bef990e7d8a881f6533 Mon Sep 17 00:00:00 2001
From: James Erwin james.erwin@intel.com Date: Fri, 1 Nov 2019 15:20:59 -0400 Subject: [PATCH] IB/hfi1: Ensure full Gen3 speed in a Gen4 system
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@awfm-01.aw.intel.... Cc: stable@vger.kernel.org Reviewed-by: Dennis Dalessandro dennis.dalessandro@intel.com Reviewed-by: Kaike Wan kaike.wan@intel.com Signed-off-by: James Erwin james.erwin@intel.com Signed-off-by: Mike Marciniszyn mike.marciniszyn@intel.com Signed-off-by: Dennis Dalessandro dennis.dalessandro@intel.com Signed-off-by: Jason Gunthorpe jgg@mellanox.com
diff --git a/drivers/infiniband/hw/hfi1/pcie.c b/drivers/infiniband/hw/hfi1/pcie.c index 61aa5504d7c3..61362bd6d3ce 100644 --- a/drivers/infiniband/hw/hfi1/pcie.c +++ b/drivers/infiniband/hw/hfi1/pcie.c @@ -319,7 +319,9 @@ int pcie_speeds(struct hfi1_devdata *dd) /* * bus->max_bus_speed is set from the bridge's linkcap Max Link Speed */ - if (parent && dd->pcidev->bus->max_bus_speed != PCIE_SPEED_8_0GT) { + if (parent && + (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; }