Re: Fast channel switching

On Tue, 2010-02-16 at 10:08 -0800, vishal11 wrote:
> Hi All
> 
> Iam a student and am trying to incorporate fast channel switching in madwifi
> for my project. Currently as measured the time for execution of the function
> ath_set_channel for madwifi_0.9.4_trunkr3314 is about 20ms (as tested on
> Mikrotik RB433AH board running openwrt kamikaze v8.09). However for the
> later releases with HAL code (madwifi_0.9.4_r3980 and later), we have
> measured the execution time for the same function to be about 4-5ms. Also we
> have noticed that there is a function for AR5212 chipset,
> ar5212ChannelChange(), whose execution time as measured is about 500
> microseconds.
> 
> However our problem is that we are not able to make madwifi_0.9.4_r3980 or
> later release (till latest r4119) work on Mikrotik RB433AH boards (employing
> Openwrt kamikaze v8.09). We have been able to compile the latest madwifi
> release on Openwrt, but when modules load, the following error message keeps
> appearing
> 
> wifi0 ath_fatal_tasklet hardware error resetting

I suggest that you do your work on free code, such as madwifi trunk or
better yet, on ath5k.  I assume you use miniPCI cards and don't need AHB
support.

HAL in MadWifi 0.9.4 is essentially a black box.

> Morever we have already incorporated quite a few changes in
> madwifi_0.9.4_trunkr3314 and it will be difficult for us to port these
> changes to latest madwifi release. So would it be possible to make use of
> the function ar5212ChannelChange() in madwifi_0.9.4_trunkr3314. What changes
> will we need to make for that?? We tried to implement the function
> ar5212ChannelChange() in madwifi_0.9.4_trunkr3314 ourselves, but have not
> been successfull so far.
> 
> Any help or suggestion would be greatly appreciated.

I doubt anyone would want to debug problems in non-free HAL at this
time.

-- 
Regards,
Pavel Roskin

------------------------------------------------------------------------------
SOLARIS 10 is the OS for Data Centers - provides features such as DTrace,
Predictive Self Healing and Award Winning ZFS. Get Solaris 10 NOW
http://p.sf.net/sfu/solaris-dev2dev