Re: [PATCH bluetooth-next 4/4] mac802154: use atomic ops for sequence incrementation

[Alexander Aring <alex.aring@gmail.com>]

On Fri, May 22, 2015 at 12:34:19PM +0200, Marc Kleine-Budde wrote:
> On 05/22/2015 12:30 PM, Stefan Schmidt wrote:
> > Hello.
> > 
> > On 22/05/15 10:59, Marc Kleine-Budde wrote:
> >> On 05/22/2015 10:57 AM, Alexander Aring wrote:
> >>> This patch will use atomic operations for sequence number incrementation
> >>> while MAC header generation. Upper layers like af_802154 or 6LoWPAN
> >>> could call this function in a parallel context while generating 802.15.4
> >>> MAC header before queuing into wpan interfaces transmit queue.
> >> what about swapping patch 3 and 4?
> > 
> > To avoid having problems during a git bisect later one? E.g. having the 
> > lock removed but no atomic in place?
> 
> Yes, that's what I was thinking about. I don't know the code to tell if
> this is an issue here.
> 

The problem is more difficult because the dsn incrementation which I do
atomic now had never a locking mechanism. So this was always not working
correctly. Somebody need to scream now "hey fix that in net, not next".
I do at the moment only critical things fixed in net, like [0].


But we should swap it because I first wrote some "TODO we should use
atomic here" and then later I decide to implement this TODO. At the end
this results in some cherry-pick orgy and I did not change it.

- Alex

[0] ("mac802154: tx: fix sync xmit handling") can't find them in the
    archive