2018-08-29 11:19:49

by Johannes Berg

[permalink] [raw]
Subject: Re: [PATCH v3 1/2] mac80211: invoke sw_scan if hw_scan returns EPERM

Huh, why did you send this like 10 times? Also, HTML is dropped by the
list ...

> > I'm not convinced - why would you set that? It seems to me that drivers
> > might, for example, still do one band in hardware and the other in
> > software, or something like that? You might also run into the WARN_ON
> > here?
>
> If we don't set this bit, observed "scan aborted" when "iw dev wlan0
> scan" command
> is given in redpine dual band modules(Didn't see any issue with single
> band module).
> sh# iw dev wlan0 scan
> scan aborted!

What happened underneath here? I'm having a hard time understanding -
perhaps you can at least capture some mac80211 event tracing for this?
perhaps with function graph tracing too, so we see where exactly the
abort happens.

Unless you already know why this happens, and that's why you set the
cancel bit?

So I think the clearer thing to do would be to have a separate bit for
this and check it in the right place.

johannes


2018-08-31 17:38:10

by Siva Rebbagondla

[permalink] [raw]
Subject: Re: [PATCH v3 1/2] mac80211: invoke sw_scan if hw_scan returns EPERM

On Wed, Aug 29, 2018 at 12:54 PM Johannes Berg
<[email protected]> wrote:
>
> Huh, why did you send this like 10 times? Also, HTML is dropped by the
> list ...
>
Hi Johannes,
There was an issue with our mailing server and we received Mail
Delivery Failure notification.
Hence, we tried multiple times by doing the changes.
Apologies for the inconvenience.
> > > I'm not convinced - why would you set that? It seems to me that drivers
> > > might, for example, still do one band in hardware and the other in
> > > software, or something like that? You might also run into the WARN_ON
> > > here?
> >
> > If we don't set this bit, observed "scan aborted" when "iw dev wlan0
> > scan" command
> > is given in redpine dual band modules(Didn't see any issue with single
> > band module).
> > sh# iw dev wlan0 scan
> > scan aborted!
>
> What happened underneath here? I'm having a hard time understanding -
> perhaps you can at least capture some mac80211 event tracing for this?
> perhaps with function graph tracing too, so we see where exactly the
> abort happens.
>
> Unless you already know why this happens, and that's why you set the
> cancel bit?
Sure Johannes. I will provide event trace or function graph details
for this and send you
the updatd patch. Is that fine?.
>
> So I think the clearer thing to do would be to have a separate bit for
> this and check it in the right place.
>
> johannes

Thanks
Siva Rebbagondla