IB/qib: Roll back PCIe tuning change
Commit 8d4548f2b ("IB/qib: Default some module parameters optimally")
introduced an issue with older root complexes. They cannot handle the
pcie_caps of 0x51 (MaxReadReq 4096, MaxPayload=256).
A typical diagnostic in this situation reported by syslog contains
the text:
[PCIe Poisoned TLP][Send DMA memory read]
Restore the module paramter default to zero with will avoid any
changes in the root complex.
Reviewed-by: Mark Debbage <mark.debbage@qlogic.com>
Signed-off-by: Mike Marciniszyn <mike.marciniszyn@qlogic.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
diff --git a/drivers/infiniband/hw/qib/qib_pcie.c b/drivers/infiniband/hw/qib/qib_pcie.c
index f695061..0fde788 100644
--- a/drivers/infiniband/hw/qib/qib_pcie.c
+++ b/drivers/infiniband/hw/qib/qib_pcie.c
@@ -560,7 +560,7 @@
* BIOS may not set PCIe bus-utilization parameters for best performance.
* Check and optionally adjust them to maximize our throughput.
*/
-static int qib_pcie_caps = 0x51;
+static int qib_pcie_caps;
module_param_named(pcie_caps, qib_pcie_caps, int, S_IRUGO);
MODULE_PARM_DESC(pcie_caps, "Max PCIe tuning: Payload (0..3), ReadReq (4..7)");