Re: [PATCH net-next v2 6/6] net/ncsi: Configure multi-package, multi-channel modes with failover

On Fri, 2018-10-26 at 21:48 +0000, Justin.Lee1@Dell.com wrote:

Hi Samuel,

There is one place that we assume the next available TX channel is under the same package.
Please see the comment below.

Thanks,
Justin


+/* Change the active Tx channel in a multi-channel setup */
+int ncsi_update_tx_channel(struct ncsi_dev_priv *ndp,

quoted

+			   struct ncsi_package *np,
+			   struct ncsi_channel *disable,
+			   struct ncsi_channel *enable)
+{
+	struct ncsi_cmd_arg nca;
+	struct ncsi_channel *nc;
+	int ret = 0;
+
+	if (!np->multi_channel)
+		netdev_warn(ndp->ndev.dev,
+			    "NCSI: Trying to update Tx channel in single-channel mode\n");
+	nca.ndp = ndp;
+	nca.package = np->id;

If the channel may be on different package, the package ID here may not be correct
in some cases.

quoted

+	nca.req_flags = 0;
+
+	/* Find current channel with Tx enabled */
+	if (!disable) {
+		NCSI_FOR_EACH_CHANNEL(np, nc)
+			if (nc->modes[NCSI_MODE_TX_ENABLE].enable)
+				disable = nc;
+	}
+
+	/* Find a suitable channel for Tx */
+	if (!enable) {
+		if (np->preferred_channel &&
+		    ncsi_channel_has_link(np->preferred_channel)) {
+			enable = np->preferred_channel;
+		} else {
+			NCSI_FOR_EACH_CHANNEL(np, nc) {
+				if (!(np->channel_whitelist & 0x1 << nc->id))
+					continue;
+				if (nc->state != NCSI_CHANNEL_ACTIVE)
+					continue;
+				if (ncsi_channel_has_link(nc)) {
+					enable = nc;
+					break;
+				}
+			}

When we search, we need to consider the other available channel might be on the
package.

Good point, I've updated this to allow for enabling Tx on a different
package.

Thanks,
Sam

quoted

+		}
+	}
+
+	if (disable == enable)
+		return -1;
+
+	if (!enable)
+		return -1;
+
+	if (disable) {
+		nca.channel = disable->id;
+		nca.type = NCSI_PKT_CMD_DCNT;
+		ret = ncsi_xmit_cmd(&nca);
+		if (ret)
+			netdev_err(ndp->ndev.dev,
+				   "Error %d sending DCNT\n",
+				   ret);
+	}

I remove the cable from ncsi0 and it doesn't failover to ncsi3 as ncsi0 and ncsi3 are not under
the same package.

cat /sys/kernel/debug/ncsi_protocol/ncsi_device_
IFIDX IFNAME NAME   PID CID RX TX MP MC WP WC PC CS PS LS RU CR NQ HA
======================================================================
  2   eth2   ncsi0  000 000 1  1  1  1  1  1  1  3  0  0  1  1  0  1
  2   eth2   ncsi1  000 001 0  0  1  1  1  0  0  1  0  1  1  1  0  1
  2   eth2   ncsi2  001 000 0  0  1  1  1  0  0  1  0  1  1  1  0  1
  2   eth2   ncsi3  001 001 1  0  1  1  1  1  0  2  1  1  1  1  0  1
======================================================================
MP: Multi-mode Package     WP: Whitelist Package
MC: Multi-mode Channel     WC: Whitelist Channel
PC: Primary Channel        CS: Channel State
PS: Poll Status            LS: Link Status
RU: Running                CR: Carrier OK
NQ: Queue Stopped          HA: Hardware Arbitration