[PATCH net-next] ibmvnic: Improve output for unsupported stats

[PATCH net-next] ibmvnic: Improve output for unsupported stats

[John Allen]

The vnic server can report -1 in the event that a given statistic is not
supported. Currently, the -1 value is implicitly cast to an unsigned
integer and appears through the ethtool -S output as a very large number.
This patch improves this behavior by reporting 0 in the event that a
given statistic is not supported.

Signed-off-by: John Allen <jallen@linux.vnet.ibm.com>
---
diff --git a/drivers/net/ethernet/ibm/ibmvnic.c b/drivers/net/ethernet/ibm/ibmvnic.c
index cb8182f..b8ad2db 100644
--- a/drivers/net/ethernet/ibm/ibmvnic.c
+++ b/drivers/net/ethernet/ibm/ibmvnic.c
@@ -1862,6 +1862,7 @@ static void ibmvnic_get_ethtool_stats(struct net_device *dev,
 {
 	struct ibmvnic_adapter *adapter = netdev_priv(dev);
 	union ibmvnic_crq crq;
+	u64 stat;
 	int i, j;

 	memset(&crq, 0, sizeof(crq));
@@ -1876,9 +1877,11 @@ static void ibmvnic_get_ethtool_stats(struct net_device *dev,
 	ibmvnic_send_crq(adapter, &crq);
 	wait_for_completion(&adapter->stats_done);

-	for (i = 0; i < ARRAY_SIZE(ibmvnic_stats); i++)
-		data[i] = be64_to_cpu(IBMVNIC_GET_STAT(adapter,
-						ibmvnic_stats[i].offset));
+	for (i = 0; i < ARRAY_SIZE(ibmvnic_stats); i++) {
+		stat = be64_to_cpu(IBMVNIC_GET_STAT(adapter,
+						    ibmvnic_stats[i].offset));
+		data[i] = stat == -1 ? 0 : stat;
+	}

 	for (j = 0; j < adapter->req_tx_queues; j++) {
 		data[i] = adapter->tx_stats_buffers[j].packets;

Re: [PATCH net-next] ibmvnic: Improve output for unsupported stats

[Andrew Lunn]

On Mon, Oct 02, 2017 at 03:31:39PM -0500, John Allen wrote:
> The vnic server can report -1 in the event that a given statistic is not
> supported. Currently, the -1 value is implicitly cast to an unsigned
> integer and appears through the ethtool -S output as a very large number.
> This patch improves this behavior by reporting 0 in the event that a
> given statistic is not supported.

Hi John

If it does not exist, why not skip it altogether?
ibmvnic_get_sset_count() could walk the list and count the valid ones.
ibmvnic_get_strings() could only return the name of the valid onces.

      Andrew

Re: [PATCH net-next] ibmvnic: Improve output for unsupported stats

[David Miller]

From: Andrew Lunn <andrew@lunn.ch>
Date: Mon, 2 Oct 2017 23:57:23 +0200

> On Mon, Oct 02, 2017 at 03:31:39PM -0500, John Allen wrote:
>> The vnic server can report -1 in the event that a given statistic is not
>> supported. Currently, the -1 value is implicitly cast to an unsigned
>> integer and appears through the ethtool -S output as a very large number.
>> This patch improves this behavior by reporting 0 in the event that a
>> given statistic is not supported.
> 
> Hi John
> 
> If it does not exist, why not skip it altogether?
> ibmvnic_get_sset_count() could walk the list and count the valid ones.
> ibmvnic_get_strings() could only return the name of the valid onces.

Agreed, skipping would be preferable to printing zero values.