release/5.2.37/bnxt_en-Do-not-treat-DSN-Digital-Serial-Number-read-.patch

From fd554bf7299c6ff74a25247938248b367f1ef862 Mon Sep 17 00:00:00 2001
From: Michael Chan <michael.chan@broadcom.com>
Date: Fri, 17 Jan 2020 00:32:47 -0500
Subject: [PATCH] bnxt_en: Do not treat DSN (Digital Serial Number) read
 failure as fatal.

commit d061b2411d5f3d6272187ab734ce0640827fca13 upstream.

DSN read can fail, for example on a kdump kernel without PCIe extended
config space support.  If DSN read fails, don't set the
BNXT_FLAG_DSN_VALID flag and continue loading.  Check the flag
to see if the stored DSN is valid before using it.  Only VF reps
creation should fail without valid DSN.

Fixes: 03213a996531 ("bnxt: move bp->switch_id initialization to PF probe")
Reported-by: Marc Smith <msmith626@gmail.com>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>

diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.c b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
index e4935a6752e4..ee1fe9d89c94 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt.c
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
@@ -10222,7 +10222,7 @@ int bnxt_get_port_parent_id(struct net_device *dev,
 		return -EOPNOTSUPP;
 
 	/* The PF and it's VF-reps only support the switchdev framework */
-	if (!BNXT_PF(bp))
+	if (!BNXT_PF(bp) || !(bp->flags & BNXT_FLAG_DSN_VALID))
 		return -EOPNOTSUPP;
 
 	ppid->id_len = sizeof(bp->switch_id);
@@ -10610,6 +10610,7 @@ static int bnxt_pcie_dsn_get(struct bnxt *bp, u8 dsn[])
 	put_unaligned_le32(dw, &dsn[0]);
 	pci_read_config_dword(pdev, pos + 4, &dw);
 	put_unaligned_le32(dw, &dsn[4]);
+	bp->flags |= BNXT_FLAG_DSN_VALID;
 	return 0;
 }
 
@@ -10761,9 +10762,7 @@ static int bnxt_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
 
 	if (BNXT_PF(bp)) {
 		/* Read the adapter's DSN to use as the eswitch switch_id */
-		rc = bnxt_pcie_dsn_get(bp, bp->switch_id);
-		if (rc)
-			goto init_err_pci_clean;
+		bnxt_pcie_dsn_get(bp, bp->switch_id);
 	}
 	bnxt_hwrm_func_qcfg(bp);
 	bnxt_hwrm_vnic_qcaps(bp);
diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.h b/drivers/net/ethernet/broadcom/bnxt/bnxt.h
index c7381f7f8cfb..d3feea85a09f 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt.h
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.h
@@ -1351,6 +1351,7 @@ struct bnxt {
 	#define BNXT_FLAG_NO_AGG_RINGS	0x20000
 	#define BNXT_FLAG_RX_PAGE_MODE	0x40000
 	#define BNXT_FLAG_MULTI_HOST	0x100000
+	#define BNXT_FLAG_DSN_VALID	0x200000
 	#define BNXT_FLAG_DOUBLE_DB	0x400000
 	#define BNXT_FLAG_CHIP_NITRO_A0	0x1000000
 	#define BNXT_FLAG_DIM		0x2000000
diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt_vfr.c b/drivers/net/ethernet/broadcom/bnxt/bnxt_vfr.c
index f760921389a3..143c7a9cbbbf 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt_vfr.c
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt_vfr.c
@@ -413,6 +413,9 @@ static int bnxt_vf_reps_create(struct bnxt *bp)
 	struct net_device *dev;
 	int rc, i;
 
+	if (!(bp->flags & BNXT_FLAG_DSN_VALID))
+		return -ENODEV;
+
 	bp->vf_reps = kcalloc(num_vfs, sizeof(vf_rep), GFP_KERNEL);
 	if (!bp->vf_reps)
 		return -ENOMEM;
-- 
2.7.4