From: Sourav <sourav.chakraborty@netcommwireless.com>
To: Helmut Schaa <helmut.schaa@googlemail.com>
Cc: Arend van Spriel <arend@broadcom.com>,
linux-wireless <linux-wireless@vger.kernel.org>
Subject: Re: Not reaching optimum speeds with IEEE 802.11n
Date: Fri, 12 Sep 2014 12:11:30 +1000 [thread overview]
Message-ID: <54125652.7060205@netcommwireless.com> (raw)
In-Reply-To: <CAGXE3d9FRLOPQ1pO6WFWy4FF67PGbo5ztfhLELydq3k410731w@mail.gmail.com>
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On 11/09/14 00:14, Helmut Schaa wrote:
> On Wed, Sep 10, 2014 at 10:42 AM, Arend van Spriel <arend@broadcom.com> wrote:
>> On 09/10/14 03:26, Sourav wrote:
>>> We are using Ralink chip Rt3072L (using rt2800usb drivers rt2800usb.c),
> The Ralink USB hardware is quite bad in reporting TX status and as
> such minstrel_ht cannot do proper rate selection.
> If you watch the rc stats at
> /sys/kernel/debug/ieee80211/phy0/netdev\:wlan0-0/stations/xx:xx:xx:xx:xx:xx/rc_stats
> you might see a lot of rate selection "hopping".
>
> Regards.
> Helmut
please take a look at the attachments.... the first one shows the
rc_stats and iperf stats side by side on the router(iperf is running in
client mode in the router).....the second attachment is from a laptop
which is running iperf in server mode.
I don't see a lot of rate "hopping" in the rc_stats file, (T,t and P)
rates are pretty much stable.... yet there is a big difference between
those rates and the throughput using iperf......
when you say "Ralink USB hardware is quite bad in reporting TX status",
do you mean that the HW reports less tx rate to minstrel_ht and so its
rate calculation is screwed up?
Can you please let me know the section of code inside
Rc_80211_minstrel_ht.c (or somewhere else) which deals with getting the
tx rate from ralink HW?
--
Warm Regards,
Sourav
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next prev parent reply other threads:[~2014-09-12 2:13 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-09-10 1:26 Not reaching optimum speeds with IEEE 802.11n Sourav
2014-09-10 8:42 ` Arend van Spriel
2014-09-10 14:14 ` Helmut Schaa
2014-09-10 15:18 ` Andreas Hartmann
2014-09-11 10:15 ` Helmut Schaa
2014-09-12 2:11 ` Sourav [this message]
2014-09-12 7:46 ` Helmut Schaa
[not found] ` <5412A831.3050804@netcommwireless.com>
2014-09-18 8:53 ` Sourav
2014-09-10 14:53 ` Andreas Hartmann
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