Subject: Re: [PATCH wpan-next v3 07/11] net: ieee802154: at86rf230: Provide meaningful error codes when possible

From: Miquel Raynal <[email-masked]>
Date: Fri, 18 Mar 2022 08:56:21 +0100

Hi Alexander,

[email-masked] wrote on Sun, 13 Mar 2022 16:16:45 -0400:

> Hi,
> 
> On Thu, Mar 3, 2022 at 1:25 PM Miquel Raynal <[email-masked]> wrote:
> >
> > Either the spi operation failed, or the device encountered an error. In
> > both case, we know more or less what happened thanks to the spi call
> > return code or the content of the TRAC register otherwise. Use them in
> > order to propagate one step above the error.
> >
> > Signed-off-by: Miquel Raynal <[email-masked]>
> > ---
> >  drivers/net/ieee802154/at86rf230.c | 25 +++++++++++++++++++++++--
> >  1 file changed, 23 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/net/ieee802154/at86rf230.c b/drivers/net/ieee802154/at86rf230.c
> > index 12ee071057d2..5f19266b3045 100644
> > --- a/drivers/net/ieee802154/at86rf230.c
> > +++ b/drivers/net/ieee802154/at86rf230.c
> > @@ -370,7 +370,27 @@ static inline void
> >  at86rf230_async_error(struct at86rf230_local *lp,
> >                       struct at86rf230_state_change *ctx, int rc)
> >  {
> > -       dev_err(&lp->spi->dev, "spi_async error %d\n", rc);
> > +       int reason;
> > +
> > +       switch (rc) {
> > +       case TRAC_CHANNEL_ACCESS_FAILURE:
> > +               reason = IEEE802154_CHANNEL_ACCESS_FAILURE;
> > +               break;
> > +       case TRAC_NO_ACK:
> > +               reason = IEEE802154_NO_ACK;
> > +               break;
> > +       case TRAC_INVALID:
> > +               reason = IEEE802154_SYSTEM_ERROR;
> > +               break;
> > +       default:
> > +               reason = rc;
> > +       }
> > +  
> 
> Actually the rc value here is not a TRAC status register value... and
> it should not be one.
> 
> The reason is because this function can also be called during a non-tx
> state change failure whereas the trac register is only valid when the
> transmission "is successfully offloaded to device" and delivers us an
> error of the transmission operation on the device. It is called during
> the tx case only if there was a "state transition error" and then it
> should report IEEE802154_SYSTEM_ERROR in
> at86rf230_async_error_recover_complete(). Whereas I think we can use
> IEEE802154_SYSTEM_ERROR as a non-specific 802.15.4 error code, because
> a bus error of a state transition is not 802.15.4 specific.

Ok I'm totally fine using SYSTEM_ERROR as a generic placeholder in
these cases.

Thanks,
Miquèl