From: Miquel Raynal <miquel.raynal@bootlin.com>
To: Alexander Aring <aahringo@redhat.com>
Cc: Alexander Aring <alex.aring@gmail.com>,
Stefan Schmidt <stefan@datenfreihafen.org>,
linux-wpan - ML <linux-wpan@vger.kernel.org>,
"David S. Miller" <davem@davemloft.net>,
Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>,
Network Development <netdev@vger.kernel.org>,
David Girault <david.girault@qorvo.com>,
Romuald Despres <romuald.despres@qorvo.com>,
Frederic Blain <frederic.blain@qorvo.com>,
Nicolas Schodet <nico@ni.fr.eu.org>,
Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Subject: Re: [PATCH wpan-next v2 09/11] net: mac802154: Introduce a synchronous API for MLME commands
Date: Tue, 17 May 2022 15:30:45 +0200 [thread overview]
Message-ID: <20220517153045.73fda4ee@xps-13> (raw)
In-Reply-To: <CAK-6q+i_T+FaK0tX6tF38VjyEfSzDi-QC85MTU2=4soepAag8g@mail.gmail.com>
aahringo@redhat.com wrote on Sun, 15 May 2022 19:03:53 -0400:
> Hi,
>
> On Sun, May 15, 2022 at 6:28 PM Alexander Aring <aahringo@redhat.com> wrote:
> >
> > Hi,
> >
> > On Thu, May 12, 2022 at 10:34 AM Miquel Raynal
> > <miquel.raynal@bootlin.com> wrote:
> > >
> > > This is the slow path, we need to wait for each command to be processed
> > > before continuing so let's introduce an helper which does the
> > > transmission and blocks until it gets notified of its asynchronous
> > > completion. This helper is going to be used when introducing scan
> > > support.
> > >
> > > Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
> > > ---
> > > net/mac802154/ieee802154_i.h | 1 +
> > > net/mac802154/tx.c | 25 +++++++++++++++++++++++++
> > > 2 files changed, 26 insertions(+)
> > >
> > > diff --git a/net/mac802154/ieee802154_i.h b/net/mac802154/ieee802154_i.h
> > > index a057827fc48a..f8b374810a11 100644
> > > --- a/net/mac802154/ieee802154_i.h
> > > +++ b/net/mac802154/ieee802154_i.h
> > > @@ -125,6 +125,7 @@ extern struct ieee802154_mlme_ops mac802154_mlme_wpan;
> > > void ieee802154_rx(struct ieee802154_local *local, struct sk_buff *skb);
> > > void ieee802154_xmit_sync_worker(struct work_struct *work);
> > > int ieee802154_sync_and_hold_queue(struct ieee802154_local *local);
> > > +int ieee802154_mlme_tx(struct ieee802154_local *local, struct sk_buff *skb);
> > > netdev_tx_t
> > > ieee802154_monitor_start_xmit(struct sk_buff *skb, struct net_device *dev);
> > > netdev_tx_t
> > > diff --git a/net/mac802154/tx.c b/net/mac802154/tx.c
> > > index 38f74b8b6740..ec8d872143ee 100644
> > > --- a/net/mac802154/tx.c
> > > +++ b/net/mac802154/tx.c
> > > @@ -128,6 +128,31 @@ int ieee802154_sync_and_hold_queue(struct ieee802154_local *local)
> > > return ieee802154_sync_queue(local);
> > > }
> > >
> > > +int ieee802154_mlme_tx(struct ieee802154_local *local, struct sk_buff *skb)
> > > +{
> > > + int ret;
> > > +
> > > + /* Avoid possible calls to ->ndo_stop() when we asynchronously perform
> > > + * MLME transmissions.
> > > + */
> > > + rtnl_lock();
> >
> > I think we should make an ASSERT_RTNL() here, the lock needs to be
> > earlier than that over the whole MLME op. MLME can trigger more than
>
> not over the whole MLME_op, that's terrible to hold the rtnl lock so
> long... so I think this is fine that some netdev call will interfere
> with this transmission.
> So forget about the ASSERT_RTNL() here, it's fine (I hope).
>
> > one message, the whole sync_hold/release queue should be earlier than
> > that... in my opinion is it not right to allow other messages so far
> > an MLME op is going on? I am not sure what the standard says to this,
> > but I think it should be stopped the whole time? All those sequence
>
> Whereas the stop of the netdev queue makes sense for the whole mlme-op
> (in my opinion).
I might still implement an MLME pre/post helper and do the queue
hold/release calls there, while only taking the rtnl from the _tx.
And I might create an mlme_tx_one() which does the pre/post calls as
well.
Would something like this fit?
Thanks,
Miquèl
next prev parent reply other threads:[~2022-05-17 13:31 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-05-12 14:33 [PATCH wpan-next v2 00/11] ieee802154: Synchronous Tx support Miquel Raynal
2022-05-12 14:33 ` [PATCH wpan-next v2 01/11] net: mac802154: Rename the synchronous xmit worker Miquel Raynal
2022-05-12 14:33 ` [PATCH wpan-next v2 02/11] net: mac802154: Rename the main tx_work struct Miquel Raynal
2022-05-12 14:33 ` [PATCH wpan-next v2 03/11] net: mac802154: Enhance the error path in the main tx helper Miquel Raynal
2022-05-12 14:33 ` [PATCH wpan-next v2 04/11] net: mac802154: Follow the count of ongoing transmissions Miquel Raynal
2022-05-12 14:33 ` [PATCH wpan-next v2 05/11] net: mac802154: Bring the hability to hold the transmit queue Miquel Raynal
2022-05-15 22:19 ` Alexander Aring
2022-05-17 9:27 ` Miquel Raynal
2022-05-17 13:19 ` Alexander Aring
2022-05-17 13:28 ` Miquel Raynal
2022-05-12 14:33 ` [PATCH wpan-next v2 06/11] net: mac802154: Create a hot tx path Miquel Raynal
2022-05-12 14:33 ` [PATCH wpan-next v2 07/11] net: mac802154: Introduce a helper to disable the queue Miquel Raynal
2022-05-12 14:33 ` [PATCH wpan-next v2 08/11] net: mac802154: Introduce a tx queue flushing mechanism Miquel Raynal
2022-05-15 22:23 ` Alexander Aring
2022-05-17 13:20 ` Miquel Raynal
2022-05-12 14:33 ` [PATCH wpan-next v2 09/11] net: mac802154: Introduce a synchronous API for MLME commands Miquel Raynal
2022-05-15 22:28 ` Alexander Aring
2022-05-15 22:56 ` Alexander Aring
2022-05-15 23:03 ` Alexander Aring
2022-05-17 13:30 ` Miquel Raynal [this message]
2022-05-18 1:14 ` Alexander Aring
2022-05-18 10:12 ` Miquel Raynal
2022-05-18 12:05 ` Alexander Aring
2022-05-18 12:37 ` Miquel Raynal
2022-05-18 13:08 ` Alexander Aring
2022-05-18 16:12 ` Miquel Raynal
2022-05-19 1:51 ` Alexander Aring
2022-05-19 14:20 ` Miquel Raynal
2022-05-12 14:33 ` [PATCH wpan-next v2 10/11] net: mac802154: Add a warning in the hot path Miquel Raynal
2022-05-15 22:30 ` Alexander Aring
2022-05-17 13:36 ` Miquel Raynal
2022-05-17 14:52 ` Miquel Raynal
2022-05-18 0:59 ` Alexander Aring
2022-05-18 9:13 ` Miquel Raynal
2022-05-12 14:33 ` [PATCH wpan-next v2 11/11] net: mac802154: Add a warning in the slow path Miquel Raynal
2022-05-15 22:30 ` Alexander Aring
2022-05-17 13:45 ` Miquel Raynal
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