Subject: Re: [PATCH] softmac: remove netif_tx_disable when scanning

From: Michael Buesch <[email-masked]>
Date: Sun, 26 Nov 2006 13:25:35 +0100

On Sunday 26 November 2006 05:05, Daniel Drake wrote:
> Larry Finger wrote:
> > In the scan section of ieee80211softmac, network transmits are disabled.
> > Clearly, this does not make any sense as transmit is necessary for active
> > scanning, and transmits are not used when passive scanning.
> 
> Probe request frames are generated by softmac and do not go through the 
> TX queue. Disabling the TX queue has no effect on that.

That's just yet another problem. ;)
The driver has its damn good reasons to disable the queue. (And only
the driver should be allowed to disable that queue). Softmac ignoring
this queue-disabled flag is just yet another bug.

> Surely disabling the queue actually makes sense, in order to avoid 
> frames designated for the "current session" being transmitted on 
> different channels during scanning?

This should be avoided by mechanisms in the firmware, as that's
the only race-free place where a "Am I on the correct channel"
check can happen. Additionally, the ieee80211 stack should
keep track of the currently set channel and don't transmit frames
on the wrong channel.

But I don't really think this is worth fixing, as it's all already
fixed in d80211 (Well, these bugs have never been in there afaik ;) ).

-- 
Greetings Michael.