Re: [PATCH v5 05/11] net: mac802154: Create a transmit bus error helper

[Miquel Raynal <miquel.raynal@bootlin.com>]

Hi Alexander,

alex.aring@gmail.com wrote on Wed, 6 Apr 2022 17:43:30 -0400:

> Hi,
> 
> On Wed, Apr 6, 2022 at 11:34 AM Miquel Raynal <miquel.raynal@bootlin.com> wrote:
> >
> > A few drivers do the full transmit operation asynchronously, which means
> > that a bus error that happens when forwarding the packet to the
> > transmitter will not be reported immediately. The solution in this case
> > is to call this new helper to free the necessary resources, restart the
> > the queue and return a generic TRAC error code: IEEE802154_SYSTEM_ERROR.
> >
> > Suggested-by: Alexander Aring <alex.aring@gmail.com>
> > Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
> > ---
> >  include/net/mac802154.h |  9 +++++++++
> >  net/mac802154/util.c    | 10 ++++++++++
> >  2 files changed, 19 insertions(+)
> >
> > diff --git a/include/net/mac802154.h b/include/net/mac802154.h
> > index abbe88dc9df5..5240d94aad8e 100644
> > --- a/include/net/mac802154.h
> > +++ b/include/net/mac802154.h
> > @@ -498,6 +498,15 @@ void ieee802154_stop_queue(struct ieee802154_hw *hw);
> >  void ieee802154_xmit_complete(struct ieee802154_hw *hw, struct sk_buff *skb,
> >                               bool ifs_handling);
> >
> > +/**
> > + * ieee802154_xmit_bus_error - frame could not be delivered to the trasmitter
> > + *                             because of a bus error
> > + *
> > + * @hw: pointer as obtained from ieee802154_alloc_hw().
> > + * @skb: buffer for transmission
> > + */
> > +void ieee802154_xmit_bus_error(struct ieee802154_hw *hw, struct sk_buff *skb);
> > +
> >  /**
> >   * ieee802154_xmit_error - frame transmission failed
> >   *
> > diff --git a/net/mac802154/util.c b/net/mac802154/util.c
> > index ec523335336c..79ba803c40c9 100644
> > --- a/net/mac802154/util.c
> > +++ b/net/mac802154/util.c
> > @@ -102,6 +102,16 @@ void ieee802154_xmit_error(struct ieee802154_hw *hw, struct sk_buff *skb,
> >  }
> >  EXPORT_SYMBOL(ieee802154_xmit_error);
> >
> > +void ieee802154_xmit_bus_error(struct ieee802154_hw *hw, struct sk_buff *skb)
> > +{
> > +       struct ieee802154_local *local = hw_to_local(hw);
> > +
> > +       local->tx_result = IEEE802154_SYSTEM_ERROR;
> > +       ieee802154_wake_queue(hw);
> > +       dev_kfree_skb_any(skb);
> > +}
> > +EXPORT_SYMBOL(ieee802154_xmit_bus_error);
> > +  
> 
> why not calling ieee802154_xmit_error(..., IEEE802154_SYSTEM_ERROR) ?
> Just don't give the user a chance to pick a error code if something
> bad happened.

Oh ok, I assumed, based on your last comment, that you wanted a
dedicated helper for that, but if just calling xmit_error() with the
a fixed value is enough I'll drop this commit.

Thanks,
Miquèl