[dpdk-stable] [PATCH] [18.11] net/mlx5: fix PCI address lookup

[Viacheslav Ovsiienko <viacheslavo@nvidia.com>]

mlx5 PMDs use the mlx5_dev_to_pci_addr() routine to convert
Infiniband device name to the Bus-Device-Function location
on the PCI bus. The routine returned success even in case of
not found identification string. On caller side it likely
caused the wrong match with the BDF of previous device
resulting in wrong representor and master recognitions.

Fixes: 771fa900b73a ("mlx5: introduce new driver for Mellanox ConnectX-4 adapters")
Cc: stable@dpdk.org

Signed-off-by: Viacheslav Ovsiienko <viacheslavo@nvidia.com>
---
 drivers/net/mlx5/mlx5_ethdev.c | 19 +++++++++++++------
 1 file changed, 13 insertions(+), 6 deletions(-)

diff --git a/drivers/net/mlx5/mlx5_ethdev.c b/drivers/net/mlx5/mlx5_ethdev.c
index e35ff32..f1ec6f2 100644
--- a/drivers/net/mlx5/mlx5_ethdev.c
+++ b/drivers/net/mlx5/mlx5_ethdev.c
@@ -968,6 +968,7 @@ struct ethtool_link_settings {
 {
 	FILE *file;
 	char line[32];
+	int rc = -ENOENT;
 	MKSTR(path, "%s/device/uevent", device->ibdev_path);
 
 	file = fopen(path, "rb");
@@ -977,16 +978,19 @@ struct ethtool_link_settings {
 	}
 	while (fgets(line, sizeof(line), file) == line) {
 		size_t len = strlen(line);
-		int ret;
 
 		/* Truncate long lines. */
-		if (len == (sizeof(line) - 1))
+		if (len == (sizeof(line) - 1)) {
 			while (line[(len - 1)] != '\n') {
-				ret = fgetc(file);
+				int ret = fgetc(file);
+
 				if (ret == EOF)
-					break;
+					goto exit;
 				line[(len - 1)] = ret;
 			}
+			/* No match for long lines. */
+			continue;
+		}
 		/* Extract information. */
 		if (sscanf(line,
 			   "PCI_SLOT_NAME="
@@ -995,12 +999,15 @@ struct ethtool_link_settings {
 			   &pci_addr->bus,
 			   &pci_addr->devid,
 			   &pci_addr->function) == 4) {
-			ret = 0;
+			rc = 0;
 			break;
 		}
 	}
+exit:
 	fclose(file);
-	return 0;
+	if (rc)
+		rte_errno = -rc;
+	return rc;
 }
 
 /**
-- 
1.8.3.1