All of lore.kernel.org
 help / color / mirror / Atom feed
From: Larry Finger <Larry.Finger@lwfinger.net>
To: Felix Fietkau <nbd@openwrt.org>
Cc: wireless <linux-wireless@vger.kernel.org>,
	"Martín Ernesto Barreyro" <barreyromartin@gmail.com>,
	"Johannes Berg" <johannes@sipsolutions.net>
Subject: Re: Minstrel rate-setting question
Date: Thu, 22 Jan 2009 21:39:19 -0600	[thread overview]
Message-ID: <49793BE7.3020509@lwfinger.net> (raw)
In-Reply-To: <497929C1.9060804@openwrt.org>

Felix Fietkau wrote:
> I believe that it's not minstrel's fault. According to the information that
> I have about RTL8187L, the chip implements rate fallback. If the chip changes
> rates during retransmissions, the status information the way you gather it
> will not be accurate and will trick minstrel into believing that higher rates
> actually work (which in fact they don't). 
> Please do some transmissions at 54M and run a monitor mode capture on a different
> card to see if it changes the rate during transmission and how frequently it
> uses one rate before falling back (if indeed my theory is correct).
> This information could be used to provide some more accurate feedback through
> multi-rate retry status information.


I believe you have the clue. There is a register named RATE_FALLBACK
and a bit called RTL818X_RATE_FALLBACK_ENABLE. I'm testing a patch
that leaves this bit unset.

Thanks,

Larry

      reply	other threads:[~2009-01-23  3:39 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <BLU144-W4266C309A1F9CD0F4B5C21B2D90@phx.gbl>
     [not found] ` <496CE438.6020408@lwfinger.net>
     [not found]   ` <BLU144-W164FB7B41C703C52AAAF9BB2D90@phx.gbl>
     [not found]     ` <496D2772.4060104@lwfinger.net>
     [not found]       ` <BLU144-W254C2D7845CD9E851F745DB2D60@phx.gbl>
     [not found]         ` <496D3118.7060906@lwfinger.net>
     [not found]           ` <BLU144-W40A7F7D25BE3B92EABD5C7B2D60@phx.gbl>
     [not found]             ` <496D665A.90608@lwfinger.net>
     [not found]               ` <BLU144-W102912CECD6EE0D07D1BD8B2D50@phx.gbl>
     [not found]                 ` <4972B1E7.7000005@lwfinger.net>
     [not found]                   ` <BLU144-W211FE279F46EA07E0D35E0B2D10@phx.gbl>
     [not found]                     ` <4977612D.7050500@lwfinger.net>
     [not found]                       ` <1232664643.4589.5.camel@note-tatin>
2009-01-23  0:16                         ` Minstrel rate-setting question Larry Finger
2009-01-23  2:21                           ` Felix Fietkau
2009-01-23  3:39                             ` Larry Finger [this message]

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=49793BE7.3020509@lwfinger.net \
    --to=larry.finger@lwfinger.net \
    --cc=barreyromartin@gmail.com \
    --cc=johannes@sipsolutions.net \
    --cc=linux-wireless@vger.kernel.org \
    --cc=nbd@openwrt.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.