[PATCH 4.18 025/235] nfp: dont fail probe on pci_sriov_set_totalvfs() errors

[Greg Kroah-Hartman]

4.18-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Jakub Kicinski <jakub.kicinski@xxxxxxxxxxxxx>

[ Upstream commit 5b0ced17edc5710d4e946392d0f2934a9e07b37f ]

On machines with buggy ACPI tables or when SR-IOV is already enabled
we may not be able to set the SR-IOV VF limit in sysfs, it's not fatal
because the limit is imposed by the driver anyway.  Only the sysfs
'sriov_totalvfs' attribute will be too high.  Print an error to inform
user about the failure but allow probe to continue.

Signed-off-by: Jakub Kicinski <jakub.kicinski@xxxxxxxxxxxxx>
Reviewed-by: Dirk van der Merwe <dirk.vandermerwe@xxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/net/ethernet/netronome/nfp/nfp_main.c |   20 ++++++++++++--------
 1 file changed, 12 insertions(+), 8 deletions(-)

--- a/drivers/net/ethernet/netronome/nfp/nfp_main.c
+++ b/drivers/net/ethernet/netronome/nfp/nfp_main.c
@@ -236,16 +236,20 @@ static int nfp_pcie_sriov_read_nfd_limit
 	int err;
 
 	pf->limit_vfs = nfp_rtsym_read_le(pf->rtbl, "nfd_vf_cfg_max_vfs", &err);
-	if (!err)
-		return pci_sriov_set_totalvfs(pf->pdev, pf->limit_vfs);
+	if (err) {
+		/* For backwards compatibility if symbol not found allow all */
+		pf->limit_vfs = ~0;
+		if (err == -ENOENT)
+			return 0;
 
-	pf->limit_vfs = ~0;
-	/* Allow any setting for backwards compatibility if symbol not found */
-	if (err == -ENOENT)
-		return 0;
+		nfp_warn(pf->cpp, "Warning: VF limit read failed: %d\n", err);
+		return err;
+	}
 
-	nfp_warn(pf->cpp, "Warning: VF limit read failed: %d\n", err);
-	return err;
+	err = pci_sriov_set_totalvfs(pf->pdev, pf->limit_vfs);
+	if (err)
+		nfp_warn(pf->cpp, "Failed to set VF count in sysfs: %d\n", err);
+	return 0;
 }
 
 static int nfp_pcie_sriov_enable(struct pci_dev *pdev, int num_vfs)