Re: [PATCH] rtl8187b: do not do per packet TX AGC

[Larry Finger <Larry.Finger@lwfinger.net>]

On 10/31/2010 11:39 PM, Herton Ronaldo Krzesinski wrote:
> I have seen the throughput issue, but on my tests it wasn't so bad.
> Usually max I got on testing was 24M while close to the AP, and it goes
> into lower speeds when going more far away, but takes a good number of
> meters to go down to 1M.
> 
> Anyway of course something isn't right. I started reviewing realtek GPL
> code (their ieee80211 drivers) and code in rtl8187 in the kernel, doing
> many tests and verifying things, trying to understand and check some
> register writes etc. (hard with missing doc or other info).
> 
> I did some cleanups, and discovered two bad things in the code. After
> the fixes, I can get normal rates (up to 54M close to the AP) without
> issue. I'll soon post the patch series to be included in
> wireless-testing, for now just for test I attach them to be easier (hope
> it isn't stripped by ML, and yes they start on 0003 through 0011 :P),
> check if with it you get better results.
> 
> The patches that matter (shown by my tests) are:
> 0010-rtl8187-remove-uneeded-setting-of-anaparam-write.patch
> 0011-rtl8187-restore-anaparam-registers-after-reset-with-.patch
> 
> but they depend on some previous patches in the series (better apply
> all), and I diffed on a tree with Thadeu's patch applied already. There
> is more cleanups and checking to do, but I probably will submit this
> initial series and later come with more ones, as with this initial
> series the throughput issue should be solved.

Good work. As you noted, patches 3 - 9 did not make any difference in the
transmit throughput. From a distance of 2 m from the AP, my 8187B yielded up to
11.4 Mb/s and an indicated rate of 24 M. Applying patch 10 raised those numbers
to 17.5 Mb/s and 48 M. Adding patch 11 raised them again to 26.9 Mb/s and 54 M,
thus getting full throughput for the 8187B and a transmit rate increase of 2.4X.

As expected, these changes had no affect on the RTL8187L. Note: The 8187L gets
values of 23.0 Mb/s and 54M - there may be a little performance gain to be
obtained from the driver.

You should submit these patches now, and feel free to add my "Acked-by:" to them.

Larry