[orbit-user] madwifi driver

[Rajesh Mahindra]

Thanks Luis. Is the ath5k driver stable?

Rajesh

On Tue, Mar 25, 2008 at 3:30 PM, Luis R. Rodriguez <mcgrof at gmail.com> wrote:

> On Tue, Mar 25, 2008 at 2:43 PM, Rajesh Mahindra
> <rajesh at winlab.rutgers.edu> wrote:
> >
> >
> > Hi
> >
> >  I need to run experiments on ORBIT which require tweaking of the CSMA
> > threshold. Does anyone have an image with the latest madwifi driver that
> has
> > this capability. Thanks
>
> Rajesh,
>
> this is not a capability but a hack as this is completely undocumented
> and only tested by a few people. However if you would like to test
> this you can change the value yourself.  Let me provide you with some
> details from ath5k which can get you on the right track:
>
> From ath5k.h:
>
> ---
>
> /* Register for RSSI threshold has a mask of 0xff, so 255 seems to
>  * be the max value. */
> #define AR5K_TUNE_RSSI_THRES                   129
> /* This must be set when setting the RSSI threshold otherwise it can
>  * prevent a reset. If AR5K_RSSI_THR is read after writing to it
>  * the BMISS_THRES will be seen as 0, seems harware doesn't keep
>  * track of it. Max value depends on harware. For AR5210 this is just 7.
>  * For AR5211+ this seems to be up to 255. */
> #define AR5K_TUNE_BMISS_THRES                  7
> ---
>
> From reg.h:
>
> ---
> /*
>  * RSSI threshold register
>  */
> #define AR5K_RSSI_THR                   0x8018          /* Register
> Address */
> #define AR5K_RSSI_THR_M                 0x000000ff      /* Mask for
> RSSI threshold [5211+] */
> #define AR5K_RSSI_THR_BMISS_5210        0x00000700      /* Mask for
> Beacon Missed threshold [5210] */
> #define AR5K_RSSI_THR_BMISS_5210_S      8
> #define AR5K_RSSI_THR_BMISS_5211        0x0000ff00      /* Mask for
> Beacon Missed threshold [5211+] */
> #define AR5K_RSSI_THR_BMISS_5211_S      8
> #define AR5K_RSSI_THR_BMISS             (ah->ah_version == AR5K_AR5210 ? \
>                                        AR5K_RSSI_THR_BMISS_5210 :
> AR5K_RSSI_THR_BMISS_5211)
> #define AR5K_RSSI_THR_BMISS_S           8
> ---
>
> You want to write to the AR5K_RSSI_THR register but as the comments
> indicate be sure to also set a value for THR_BMISS as otherwise you
> won't be able to complete a reset with the card (this will time out).
>
>  Luis
> _______________________________________________
> orbit-user mailing list
> orbit-user at orbit-lab.org
> http://orbit-lab.org/cgi-bin/mailman/listinfo/orbit-user
>



-- 
Rajesh Mahindra
Assistant Researcher
NEC Laboratories America
Princeton
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://orbit-lab.org/pipermail/orbit-user/attachments/20080325/ea1bd557/attachment.htm>