From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dylan Cristiani Date: Fri, 21 Jan 2011 22:54:08 +0100 Subject: Trouble using bcm4318 compact flash with b43 driver In-Reply-To: <4D39C0B9.8050708@lwfinger.net> References: <20110114182113.0000753f@unknown> <4D309B73.8050402@lwfinger.net> <20110115080500.00001c48@unknown> <4D31CDA3.9040304@lwfinger.net> <20110117110618.0000170f@unknown> <20110117145106.00001ec8@unknown> <20110118115855.00007877@unknown> <4D35A506.3090702@lwfinger.net> <20110119140328.00002dd2@unknown> <20110121165137.000016ff@unknown> <4D39C0B9.8050708@lwfinger.net> Message-ID: <20110121225408.00003e2c@unknown> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: b43-dev@lists.infradead.org On Fri, 21 Jan 2011 11:22:01 -0600 Larry Finger wrote: > On 01/21/2011 09:51 AM, Dylan Cristiani wrote: > > probably i found a clue (maybe the point): when the b43 wlan > > interface comes up its rate is, at the beginning, setted to the > > lowest possible: 1Mbit, as i can see with iwconfig, and it seems > > that, at this low rates, some access points doesn't work, becuase > > of some handshake timeout failure happening or other different > > timeouts issue, like they can't 'deal' with such communication > > being too slow; if i set higher rates (i.e. 'iw set rate 24M') it > > associates to access point (WPA2 encryption), it gets dhcp address > > and it is possible to ping other net's nodes, also if there are > > still some issue, like high percentage of packet lost and so on; > > furthermore, trying to force setting of the rate to highest > > possible 'iw set rate 54M', doesn't improve the performances but, > > at the opposite, it leads again to association failures; is this a > > normal behaviour? do you think that i'm doing something wrong? why > > is the starting rate setted to 1M (it's a wlan module policy or a > > driver choice?); which is the best way to solve this issue if any? > > > > as usual thanks for you support and patience!! > > Your finding may be a good clue, but I'm not sure how to interpret > it. Any AP must be able to handle traffic at 1 Mbps. Consider a > station at an extreme distance where rates no higher that 1M can be > supported. In addition, all management frames are sent at 1M to > minimize the chances of packet loss. ok so that's normal and sensible policy and for sure very reasonable in fact maybe my question was little blind (near to stupid!) > > You may have found a bug in the firmware of the AP, although that is > not too likely. What make and model is the AP and what firmware > version is it using? problems came up with motorola wireless switch RFS6000 and access port650; but same problems with motorola ap7131 and less with ap5131 > > Fixing the transmission rate at too high a value will reduce > throughput, just as you see because of transmission errors. Any new > connection always starts at 1M. The rate-control algorithm will then > increase the rate until the error rate increases. same as first point i was blind and hasty but you know when something is not working, you change something and it works, then you revert it but it still works it's not a good feeling, because you cannot target the problem... > > I think you must do the git bisection to find the kernel change that > caused the problem. I know that it is a lot of work, but at least you > already know how to compile a kernel. yes at least, other than bother community ;-), i know how to compile the kernel i think i'm over thousand, only with 2.6.36 i reached more than 200 :-(; btw tks for you time, i'll bisect kernel but i'm not really sure that it's a question of driver's problem, because as i told you same kernel version sometimes works sometimes not. dyl