Re: [ath5k-devel] Unusually low speeds with ath5k and iwl3945

[Benoit PAPILLAULT <benoit.papillault@free.fr>]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

=46elix Fietkau a =E9crit :
> While reading the code for calculating the frame duration, i noticed
> something odd: It doesn't seem to be taking into account the short
> vs long preamble distinction for ERP rates. IMHO this might be causin=
g
> issues like this. I've seen similar behaviour a long time ago when te=
sting
> iwl3945 against a Broadcom AP with exactly the same throughput drop (=
500-
> 600 kbits/s).
> When I analyzed the problem with an extra monitor mode card, I found =
out
> that the throughput drop is caused by a huge number of retransmission=
s,

In the test I've done, there was no retransmission at all (no
duplicates). I don't save a capture file, so I cannot tell for sure.

What is the code computing frame duration you are referring to? How it
could affect the hardware behavior?

> and if I remember correctly (I didn't look for this specifically back=
 then),
> the retransmissions went down the rate scaling table until they hit t=
he
> first non-ERP rate and that one worked on the first try.
>=20
> Johannes, does that sound like a probable cause? If so, it should be =
easy
> to fix.
>=20
> - Felix
>=20

Regards,
Benoit
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.6 (GNU/Linux)
Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org

iD8DBQFJLFX8OR6EySwP7oIRAp2pAJ0batdz64sh9L82CIKzkmVcLyANygCeOq5q
D18DQ/Ko9ggdGn5lmshlMJs=3D
=3D3efH
-----END PGP SIGNATURE-----
--
To unsubscribe from this list: send the line "unsubscribe linux-wireles=
s" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html