[PATCH net-next v2 5/6] net/ncsi: Reset channel state in ncsi_start_dev()
Samuel Mendoza-Jonas
sam at mendozajonas.com
Thu Nov 1 15:30:38 AEDT 2018
On Tue, 2018-10-30 at 18:23 +0000, Justin.Lee1 at Dell.com wrote:
> > On Fri, 2018-10-26 at 17:25 +0000, Justin.Lee1 at Dell.com wrote:
> > > Hi Samuel,
> > >
> > > I noticed a few issues and commented below.
> > >
> > > Thanks,
> > > Justin
> > >
> > >
> > > > /* Resources */
> > > > +int ncsi_reset_dev(struct ncsi_dev *nd);
> > > > void ncsi_start_channel_monitor(struct ncsi_channel *nc);
> > > > void ncsi_stop_channel_monitor(struct ncsi_channel *nc);
> > > > struct ncsi_channel *ncsi_find_channel(struct ncsi_package *np,
> > > > diff --git a/net/ncsi/ncsi-manage.c b/net/ncsi/ncsi-manage.c
> > > > index 014321ad31d3..9bad03e3fa5e 100644
> > > > --- a/net/ncsi/ncsi-manage.c
> > > > +++ b/net/ncsi/ncsi-manage.c
> > > > @@ -550,8 +550,10 @@ static void ncsi_suspend_channel(struct ncsi_dev_priv *ndp)
> > > > spin_lock_irqsave(&nc->lock, flags);
> > > > nc->state = NCSI_CHANNEL_INACTIVE;
> > > > spin_unlock_irqrestore(&nc->lock, flags);
> > > > - ncsi_process_next_channel(ndp);
> > > > -
> > > > + if (ndp->flags & NCSI_DEV_RESET)
> > > > + ncsi_reset_dev(nd);
> > > > + else
> > > > + ncsi_process_next_channel(ndp);
> > > > break;
> > > > default:
> > > > netdev_warn(nd->dev, "Wrong NCSI state 0x%x in suspend\n",
> > > > @@ -1554,7 +1556,7 @@ int ncsi_start_dev(struct ncsi_dev *nd)
> > > > return 0;
> > > > }
> > > >
> > > > - return ncsi_choose_active_channel(nd);
> > > > + return ncsi_reset_dev(nd);
> > >
> > > If there is no available channel due to the whitelist, ncsi_start_dev() function will return failed
> > > Status and the network interface may fail to bring up too. It is possible for user to disable all
> > > channels and leave the interface up for checking the LOM status.
> > >
> >
> > I'm not sure that that is a bug, or at least not in the scope of this
> > series. If the whitelist is set such that no channels are valid then
> > there's nothing for NCSI to do. If we want to do something like always
> > monitor all channels then that would be best to do in another patch.
> >
> > > > }
> > > > EXPORT_SYMBOL_GPL(ncsi_start_dev);
> > >
> > > Also, if I send set_package_mask and set_channel_mask commands back to back in a program,
> > > the state machine doesn't work well. If I use command line and wait for it to complete for
> > > each step, then it is fine.
> >
> > Yeah that's not great; probably hitting some corner cases in the NCSI
> > locking. I'll look into the multi-channel related stuff but I have a
> > feeling that if you tried this with the existing set/clear commands you
> > would probably hit something similar, especially on your dual core
> > platform. If so this is probably something to fix separately.
> >
>
> It is possible that it is causing by the following code in ncsi_reset_dev() function.
> The state might be overwritten and the previous operation is interrupted.
>
> 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;
Yep, we should probably add a check before calling ncsi_reset_dev() in
the netlink code if we're already in reset, and check in ncsi_reset_dev()
if we mid-configuration.
For your trace below can you share exactly which commands you were
sending? Those messages aren't upstream so it's not 100% clear what's
being sent.
Thanks!
Sam
>
> > > npcm7xx-emc f0825000.eth eth2: NCSI: Multi-package enabled on ifindex 2, mask 0x00000001
> > > npcm7xx-emc f0825000.eth eth2: NCSI: ncsi_stop_channel_monitor() - pkg 0 ch 0
> > > npcm7xx-emc f0825000.eth eth2: NCSI: ncsi_dev_work()
> > > npcm7xx-emc f0825000.eth eth2: NCSI: ncsi_suspend_channel() - pkg 0 ch 0 state 0400
> > > npcm7xx-emc f0825000.eth eth2: NCSI: pkg 0 ch 0 set as preferred channel
> > > npcm7xx-emc f0825000.eth eth2: NCSI: Multi-channel enabled on ifindex 2, mask 0x00000003
> > > npcm7xx-emc f0825000.eth eth2: NCSI: ncsi_stop_channel_monitor() - pkg 0 ch 1
> > > npcm7xx-emc f0825000.eth eth2: NCSI: ncsi_dev_work()
> > > npcm7xx-emc f0825000.eth eth2: NCSI: ncsi_suspend_channel() - pkg 0 ch 1 state 0400
> > > npcm7xx-emc f0825000.eth eth2: NCSI: Package 1 set to all channels disabled
> > > npcm7xx-emc f0825000.eth eth2: NCSI: Multi-channel enabled on ifindex 2, mask 0x00000000
> > > npcm7xx-emc f0825000.eth eth2: NCSI: ncsi_choose_active_channel()
> > > npcm7xx-emc f0825000.eth eth2: NCSI: ncsi_choose_active_channel() - pkg 0
> > > npcm7xx-emc f0825000.eth eth2: NCSI: ncsi_choose_active_channel() - pass pkg whitelist
> > > npcm7xx-emc f0825000.eth eth2: NCSI: ncsi_choose_active_channel() - ch 0
> > > npcm7xx-emc f0825000.eth eth2: NCSI: ncsi_choose_active_channel() - pass ch whitelist
> > > npcm7xx-emc f0825000.eth eth2: NCSI: ncsi_choose_active_channel() - skip
> > > npcm7xx-emc f0825000.eth eth2: NCSI: ncsi_choose_active_channel() - ch 1
> > > npcm7xx-emc f0825000.eth eth2: NCSI: ncsi_choose_active_channel() - pass ch whitelist
> > > npcm7xx-emc f0825000.eth eth2: NCSI: ncsi_choose_active_channel() - skip
> > > npcm7xx-emc f0825000.eth eth2: NCSI: ncsi_choose_active_channel() - next pkg
> > > npcm7xx-emc f0825000.eth eth2: NCSI: ncsi_choose_active_channel() - pkg 1
> > > npcm7xx-emc f0825000.eth eth2: NCSI: No channel found to configure!
> > > npcm7xx-emc f0825000.eth eth2: NCSI interface down
> > > npcm7xx-emc f0825000.eth eth2: NCSI: ncsi_dev_work()
> > > npcm7xx-emc f0825000.eth eth2: Wrong NCSI state 0x100 in workqueue
> > >
> > > All masks are set correctly, but you can see the PS column is not right and channel doesn't
> > > configure correctly.
> > >
> > > /sys/kernel/debug/ncsi_protocol# cat ncsi_device_status
> > > IFIDX IFNAME NAME PID CID RX TX MP MC WP WC PC PS LS RU CR NQ HA
> > > ===================================================================
> > > 2 eth2 ncsi0 000 000 1 1 1 1 1 1 1 0 1 1 1 0 1
> > > 2 eth2 ncsi1 000 001 1 0 1 1 1 1 0 0 1 1 1 0 1
> > > 2 eth2 ncsi2 001 000 0 0 1 1 0 0 0 0 1 1 1 0 1
> > > 2 eth2 ncsi3 001 001 0 0 1 1 0 0 0 0 1 1 1 0 1
> > > ===================================================================
> > > MP: Multi-mode Package WP: Whitelist Package
> > > MC: Multi-mode Channel WC: Whitelist Channel
> > > PC: Primary Channel
> > > PS: Poll Status
> > > LS: Link Status
> > > RU: Running
> > > CR: Carrier OK
> > > NQ: Queue Stopped
> > > HA: Hardware Arbitration
> > >
> > > PS column is getting from (int)nc->monitor.enabled.
>
>
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