net/ncsi: Fix stale link state of inactive channels on failover (008a424a) · Commits · 戴 / test

The issue was found on BCM5718 which has two NCSI channels in one package: C0 and C1. Both of them are connected to different LANs, means they are in link-up state and C0 is chosen as the active one until resetting BCM5718 happens as below. Resetting BCM5718 results in LSC (Link State Change) AEN packet received on C0, meaning LSC AEN is missed on C1. When LSC AEN packet received on C0 to report link-down, it fails over to C1 because C1 is in link-up state as software can see. However, C1 is in link-down state in hardware. It means the link state is out of synchronization between hardware and software, resulting in inappropriate channel (C1) selected as active one. This resolves the issue by sending separate GLS (Get Link Status) commands to all channels in the package before trying to do failover. The last link states of all channels in the package are retrieved. With it, C0 (not C1) is selected as active one as expected. Signed-off-by:

Gavin Shan <gwshan@linux.vnet.ibm.com> Signed-off-by:

David S. Miller <davem@davemloft.net>

net/ncsi/internal.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -246,6 +246,7 @@ enum {
		ncsi_dev_state_config_gls,
		ncsi_dev_state_config_done,
		ncsi_dev_state_suspend_select = 0x0401,
		ncsi_dev_state_suspend_gls,
		ncsi_dev_state_suspend_dcnt,
		ncsi_dev_state_suspend_dc,
		ncsi_dev_state_suspend_deselect,

net/ncsi/ncsi-manage.c

+27 −1

Original line number	Diff line number	Diff line
		@@ -550,10 +550,36 @@ static void ncsi_suspend_channel(struct ncsi_dev_priv *ndp)
		else
		nca.bytes[0] = 1;

		/* To retrieve the last link states of channels in current
		* package when current active channel needs fail over to
		* another one. It means we will possibly select another
		* channel as next active one. The link states of channels
		* are most important factor of the selection. So we need
		* accurate link states. Unfortunately, the link states on
		* inactive channels can't be updated with LSC AEN in time.
		*/
		if (ndp->flags & NCSI_DEV_RESHUFFLE)
		nd->state = ncsi_dev_state_suspend_gls;
		else
		nd->state = ncsi_dev_state_suspend_dcnt;
		ret = ncsi_xmit_cmd(&nca);
		if (ret)
		goto error;

		break;
		case ncsi_dev_state_suspend_gls:
		ndp->pending_req_num = np->channel_num;

		nca.type = NCSI_PKT_CMD_GLS;
		nca.package = np->id;

		nd->state = ncsi_dev_state_suspend_dcnt;
		NCSI_FOR_EACH_CHANNEL(np, nc) {
		nca.channel = nc->id;
		ret = ncsi_xmit_cmd(&nca);
		if (ret)
		goto error;
		}

		break;
		case ncsi_dev_state_suspend_dcnt:

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