Ticket #867 (closed defect: fixed)

Opened 5 years ago

Last modified 5 years ago

Cannot control rate

Reported by: gyiakoumis@hotmail.com Assigned to: mrenzmann
Priority: minor Milestone: version 0.9.3
Component: madwifi: driver Version: v0.9.2
Keywords: Cc:
Patch is attached: 0 Pending:

Description

Hello, I installed madwifi v. 0.9.2 in my FC ( kernel 2.6.9 ). Everything works fine, i can connect to my AP etc etc. The only problem that i get, is when i try to sate the rate parameter. I set it to a valid value ( 2M ) through iwconfig ( iwconfig ath0 rate 2M ). Eventhough the command seems to be executed correctly and the next iwconfig command gives me the new bitrate ( 2M ), it doesn't make any difference to the performance, since i am able to transmit with speeds much higher than this. I read something similar about sensitivity parameter but no fix for it. Is it possible to control the rate with this driver? And if not, which version should i use in order to do it?

Thanks, Yiannis

Attachments

change_rate_fix.diff (1.3 kB) - added by tjalling.hattink@ti-wmc.nl on 11/02/06 15:19:45.
Patch for fixing the reset issue after changing the radio rate.

Change History

09/08/06 11:23:36 changed by mrenzmann

  • priority changed from major to minor.
  • version set to v0.9.2.

Can you explain your setup a little more in detail, the configuration of the involved components (AP and client) and how you perform your testing?

For example, setting the bit rate on one side only affects packets that are sent from this host. If in that scenario your client most of the time receives data rather than sending it, you won't notice significant changes in throughput.

09/08/06 12:24:09 changed by gyiakoumis@hotmail.com

The system consists of a sender, an AP and a receiver. Sender is connected wirelessly in the AP, while receiver is connected wired. AP is Linksys Befw-11-S4 v2, sender is PCMCIA linksys card plugged through a PCMCIA to PCI adapter. Data flow is from the sender to the receiver, thus changing the rate of the sender should have a great impact on the performance.

The testing is clear, sending a video stream of 5Mbps bitrate. Lower bitrates should produce artifacts, blocking etc in the receiver side.

Regards, Yiannis

11/02/06 09:34:02 changed by tjalling.hattink@ti-wmc.nl

I'm having the same behaviour using r1708 of the drivers. I've created an ad-hoc network with two radios and I change the rate of both cards with "iwconfig ath0 rate 11M". The command is successful and iwconfig reports the correct rate but the throughput stays on 54M. I also replaced the sample algorithm with amrr and it didn't help so the problem probably does not lie in the sample modules.

11/02/06 09:56:31 changed by mrenzmann

  • status changed from new to assigned.
  • owner set to mrenzmann.
  • milestone set to version 0.9.x - progressive release candidate phase.

This should be investigated then. If anyone wants to take up on this, feel free to reassign the ticket to your account - otherwise I will try to look at it myself when I find some time for it (which is probably not before two or three weeks).

11/02/06 15:18:54 changed by tjalling.hattink@ti-wmc.nl

I found the bug causing this problem. It was caused by the radio not being resetted after a rate change was requested. The attached patch should fix this problem.

Signed-off-by: Tjalling Hattink <tjalling.hattink@ti-wmc.nl> Twente Institute of Wireless and Mobile Communications

11/02/06 15:19:45 changed by tjalling.hattink@ti-wmc.nl

  • attachment change_rate_fix.diff added.

Patch for fixing the reset issue after changing the radio rate.

11/03/06 06:52:34 changed by mrenzmann

  • milestone changed from version 0.9.x - progressive release candidate phase to version 0.9.3.

Thanks for the patch, it looks good and should be committed soon.

I suggest that the source needs to be checked for other places where EWHATEVER is returned instead of -EWHATEVER to indicate an error.

12/08/06 14:11:06 changed by mrenzmann

  • status changed from assigned to closed.
  • resolution set to fixed.

Patch committed in r1846.

12/08/06 20:26:15 changed by Ron Dippold

With r1850 I am now able to do a iwconfig ath0 rate 6M and immediately see it take effect in an iperf. No need to trick the chip into resetting any more. Looks good, thanks.

12/11/06 16:26:53 changed by mrenzmann

@Ron: Thanks for the feedback.

Add/Change #867 (Cannot control rate)