Commit 8d4548f2b ("IB/qib: Default some module parameters optimally")
introduced an issue with older root complexes. They cannot handle
the pcie_caps of 0x51.
A typical diagnostic in this situation reported by syslog contains
the text:
[PCIe Poisoned TLP][Send DMA memory read]
Insure the 0x51 is not used on the suspect chip sets.
Reviewed-by: Mark Debbage <[email protected]>
Signed-off-by: Mike Marciniszyn <[email protected]>
---
drivers/infiniband/hw/qib/qib_pcie.c | 19 ++++++++++++++-----
1 files changed, 14 insertions(+), 5 deletions(-)
diff --git a/drivers/infiniband/hw/qib/qib_pcie.c
b/drivers/infiniband/hw/qib/qib_pcie.c
index 0de55c0..bb23ba0 100644
--- a/drivers/infiniband/hw/qib/qib_pcie.c
+++ b/drivers/infiniband/hw/qib/qib_pcie.c
@@ -577,7 +577,7 @@ static int qib_tune_pcie_coalesce(struct qib_devdata *dd)
* 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)");
@@ -589,6 +589,7 @@ static int qib_tune_pcie_caps(struct qib_devdata *dd)
u16 pcaps, pctl, ecaps, ectl;
int rc_sup, ep_sup;
int rc_cur, ep_cur;
+ int caps = 0x51; /* may be overridden below */
/* Find out supported and configured values for parent (root) */
parent = dd->pcidev->bus->self;
@@ -609,6 +610,14 @@ static int qib_tune_pcie_caps(struct qib_devdata *dd)
pci_read_config_word(dd->pcidev, epos + PCI_EXP_DEVCTL, &ectl);
} else
goto bail;
+ if (!qib_pcie_caps) {
+ u16 devid = parent->device;
+ if ((devid >= 0x25e2 && devid <= 0x25fa) ||
+ (devid >= 0x65e2 && devid <= 0x65fa) ||
+ (devid >= 0x4021 && devid <= 0x402e))
+ caps = 0;
+ } else
+ caps = qib_pcie_caps;
ret = 0;
/* Find max payload supported by root, endpoint */
rc_sup = fld2val(pcaps, PCI_EXP_DEVCAP_PAYLOAD);
@@ -620,8 +629,8 @@ static int qib_tune_pcie_caps(struct qib_devdata *dd)
ep_cur = fld2val(ectl, PCI_EXP_DEVCTL_PAYLOAD);
/* If Supported greater than limit in module param, limit it */
- if (rc_sup > (qib_pcie_caps & 7))
- rc_sup = qib_pcie_caps & 7;
+ if (rc_sup > (caps & 7))
+ rc_sup = caps & 7;
/* If less than (allowed, supported), bump root payload */
if (rc_sup > rc_cur) {
rc_cur = rc_sup;
@@ -643,8 +652,8 @@ static int qib_tune_pcie_caps(struct qib_devdata *dd)
* which is code '5' (log2(4096) - 7)
*/
rc_sup = 5;
- if (rc_sup > ((qib_pcie_caps >> 4) & 7))
- rc_sup = (qib_pcie_caps >> 4) & 7;
+ if (rc_sup > ((caps >> 4) & 7))
+ rc_sup = (caps >> 4) & 7;
rc_cur = fld2val(pctl, PCI_EXP_DEVCTL_READRQ);
ep_cur = fld2val(ectl, PCI_EXP_DEVCTL_READRQ);
--
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