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SubjectRe: [PATCH net-next 5/6] net/ncsi: Reset channel state in ncsi_start_dev()
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On Mon, 2018-11-05 at 18:01 +0000, Justin.Lee1@Dell.com wrote:
> > On Tue, 2018-10-30 at 21:26 +0000, Justin.Lee1@Dell.com wrote:
> > > > +int ncsi_reset_dev(struct ncsi_dev *nd)
> > > > +{
> > > > + struct ncsi_dev_priv *ndp = TO_NCSI_DEV_PRIV(nd);
> > > > + struct ncsi_channel *nc, *active;
> > > > + struct ncsi_package *np;
> > > > + unsigned long flags;
> > > > + bool enabled;
> > > > + int state;
> > > > +
> > > > + active = NULL;
> > > > + NCSI_FOR_EACH_PACKAGE(ndp, np) {
> > > > + NCSI_FOR_EACH_CHANNEL(np, nc) {
> > > > + spin_lock_irqsave(&nc->lock, flags);
> > > > + enabled = nc->monitor.enabled;
> > > > + state = nc->state;
> > > > + spin_unlock_irqrestore(&nc->lock, flags);
> > > > +
> > > > + if (enabled)
> > > > + ncsi_stop_channel_monitor(nc);
> > > > + if (state == NCSI_CHANNEL_ACTIVE) {
> > > > + active = nc;
> > > > + break;
> > >
> > > Is the original intention to process the channel one by one?
> > > If it is the case, there are two loops and we might need to use
> > > "goto found" instead.
> >
> > Yes we'll need to break out of the package loop here as well.
> >
> > > > + }
> > > > + }
> > > > + }
> > > > +
> > >
> > > found: ?
> > >
> > > > + if (!active) {
> > > > + /* Done */
> > > > + spin_lock_irqsave(&ndp->lock, flags);
> > > > + ndp->flags &= ~NCSI_DEV_RESET;
> > > > + spin_unlock_irqrestore(&ndp->lock, flags);
> > > > + return ncsi_choose_active_channel(ndp);
> > > > + }
> > > > +
> > > > + spin_lock_irqsave(&ndp->lock, flags);
> > > > + ndp->flags |= NCSI_DEV_RESET;
> > > > + ndp->active_channel = active;
> > > > + ndp->active_package = active->package;
> > > > + spin_unlock_irqrestore(&ndp->lock, flags);
> > > > +
> > > > + nd->state = ncsi_dev_state_suspend;
> > > > + schedule_work(&ndp->work);
> > > > + return 0;
> > > > +}
> > >
> > > Also similar issue in ncsi_choose_active_channel() function below.
> > >
> > > > @@ -916,32 +1045,49 @@ static int ncsi_choose_active_channel(struct ncsi_dev_priv *ndp)
> > > >
> > > > ncm = &nc->modes[NCSI_MODE_LINK];
> > > > if (ncm->data[2] & 0x1) {
> > > > - spin_unlock_irqrestore(&nc->lock, flags);
> > > > found = nc;
> > > > - goto out;
> > > > + with_link = true;
> > > > }
> > > >
> > > > - spin_unlock_irqrestore(&nc->lock, flags);
> > > > + /* If multi_channel is enabled configure all valid
> > > > + * channels whether or not they currently have link
> > > > + * so they will have AENs enabled.
> > > > + */
> > > > + if (with_link || np->multi_channel) {
> > >
> > > I notice that there is a case that we will misconfigure the interface.
> > > For example below, multi-channel is not enable for package 1.
> > > But we enable the channel for ncsi2 below (package 1 channel 0) as that interface is the first
> > > channel for that package with link.
> >
> > I don't think I see the issue here; multi-channel is not set on package
> > 1, but both channels are in the channel whitelist. Channel 0 is
> > configured since it's the first found on package 1, and channel 1 is not
> > since channel 0 is already found. Are you expecting something different?
> >
>
> The setting is that multi-package is enable for both package 0 and 1.
> Multi-channel is only enabled for package 0.
>
> > > 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 0 2 1 1 1 1 0 1
> > > 2 eth2 ncsi1 000 001 1 0 1 1 1 1 0 2 1 1 1 1 0 1
> > > 2 eth2 ncsi2 001 000 1 0 1 0 1 1 0 2 1 1 1 1 0 1
>
> I was replying to the wrong old email and it might cause a bit confusion.
> The first 1 meaning channel is enabled for package 1 channel 0 (ncsi2).
> For eth2, we already has ncsi0 as the active channel with TX enable.
> I would think that package doesn't have the multi-channel enabled and
> we should not enable the channel for ncsi2. The problem is that package 1 doesn't
> enable the multi-channel and it believes it needs to enable one channel for its package
> but it doesn't aware that the other package already has one active channel.

Ah, maybe the confusion here is that multi_channel is a per-package
setting; it determines what a package does with its own channels.

So you have package 0 with multi-channel enabled so it enables channels 0
& 1.
Then you have package 1 without multi-channel so it enables only channel
0.
There is still only one Tx channel (package 0, channel 0).

Does that sound right, or have I missed something?

>
> > > 2 eth2 ncsi3 001 001 0 0 1 0 1 1 0 1 0 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 IA/A/IV 1/2/3
> > > PS: Poll Status LS: Link Status
> > > RU: Running CR: Carrier OK
> > > NQ: Queue Stopped HA: Hardware Arbitration
> > >
> > > I temporally change to the following to avoid that.
> > > if ((with_link &&
> > > !np->multi_channel &&
> > > list_empty(&ndp->channel_queue)) || np->multi_channel) {
> > >
> > > > + spin_lock_irqsave(&ndp->lock, flags);
> > > > + list_add_tail_rcu(&nc->link,
> > > > + &ndp->channel_queue);
> > > > + spin_unlock_irqrestore(&ndp->lock, flags);
> > > > +
> > > > + netdev_dbg(ndp->ndev.dev,
> > > > + "NCSI: Channel %u added to queue (link %s)\n",
> > > > + nc->id,
> > > > + ncm->data[2] & 0x1 ? "up" : "down");
> > > > + }
> > > > +
> > > > + spin_unlock_irqrestore(&nc->lock, cflags);
> > > > +
> > > > + if (with_link && !np->multi_channel)
> > > > + break;
> > >
> > > Similar issue here. As we are using break, so each package will configure one active TX.
> > >
> >
> > I believe this is handled properly in ncsi_channel_is_tx() in the most
> > recent revision.
>
> I saw this issue with the last revision. I was using the wrong email to reply.
>
> > > > }
> > > > + if (with_link && !ndp->multi_package)
> > > > + break;
> > > > }
> > > >
> > > > - if (!found) {
> > > > + if (list_empty(&ndp->channel_queue) && found) {
> > > > + netdev_info(ndp->ndev.dev,
> > > > + "NCSI: No channel with link found, configuring channel %u\n",
> > > > + found->id);
> > > > + spin_lock_irqsave(&ndp->lock, flags);
> > > > + list_add_tail_rcu(&found->link, &ndp->channel_queue);
> > > > + spin_unlock_irqrestore(&ndp->lock, flags);
> > > > + } else if (!found) {
> > > > netdev_warn(ndp->ndev.dev,
> > > > - "NCSI: No channel found with link\n");
> > > > + "NCSI: No channel found to configure!\n");
> > > > ncsi_report_link(ndp, true);
> > > > return -ENODEV;
> > > > }
> > >
> > > Also, for deselect package handler function, do we want to set to inactive here?
> > > If we just change the state, the cached data still keeps the old value. If the new
> > > ncsi_reset_dev() function is handling one by one, can we skip this part?
> >
> > Technically yes we could skip the state change here since
> > ncsi_reset_dev() will have already done it. However if we send a DP
> > command via some other means then it is probably best to ensure we treat
> > all channels on that package as inactive.
>
> When I tested, if I didn't comment out the state change in response handler,
> ncsi_reset_dev() function will not handle properly and some channels got into
> invisible state and at the end we lost those selectable channels.

Well that's not good :)
The deselect package command should only be sent once all channels on a
package have become inactive, so I wouldn't expect it to interfere with
ncsi_reset_dev(), but perhaps this gets combined with the issues sending
netlink commands close together. I'll investigate, if I'm lucky this will
be resolved with the same fixes.

>
> > > static int ncsi_rsp_handler_dp(struct ncsi_request *nr)
> > > {
> > > struct ncsi_rsp_pkt *rsp;
> > > struct ncsi_dev_priv *ndp = nr->ndp;
> > > struct ncsi_package *np;
> > > struct ncsi_channel *nc;
> > > unsigned long flags;
> > >
> > > /* Find the package */
> > > rsp = (struct ncsi_rsp_pkt *)skb_network_header(nr->rsp);
> > > ncsi_find_package_and_channel(ndp, rsp->rsp.common.channel,
> > > &np, NULL);
> > > if (!np)
> > > return -ENODEV;
> > >
> > > /* Change state of all channels attached to the package */
> > > NCSI_FOR_EACH_CHANNEL(np, nc) {
> > > spin_lock_irqsave(&nc->lock, flags);
> > > nc->state = NCSI_CHANNEL_INACTIVE;
> > >
> > > spin_unlock_irqrestore(&nc->lock, flags);
> > > }
> > >
> > > return 0;
> > > }
> > >
> > >
>
>


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