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Improvements in b43 for N-PHY rev 3+
Earlier tests have shown we can not transmit on OFDM rates in case of 14e4:432b (PHY rev 4). Fortunately fix was really easy, we were just missing static tables for higher revisions. Adding it allowed TX on 54M rate, 11M is not maximum anymore :)
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First b43 N-PHY benchmarks and improvements
From the first moment of enabling support for N-PHYs devices we were suffering from PHY errors and low TX performance. Fortunately some quick tests has shown that forcing rate to some of CCK values (1M, 2M, 5.5M, 11M) silences most of the PHY errors. On the other hard switching to any OFDM rate (anything except 1/2/5.5/11) stops transmission completely and produces PHY errors. So we knew that our two problems were related and we got some clue.
The good news is that Larry figured out that there is some special field in TX header that should be correctly filled for LP-PHY and N-PHY devices. The great news is that implementing support for filling this field made OFDM transmission possible :) So with the patch that was just submitted to linux-wireless, we can finally achieve some normal speeds with b43 :)
As part of testing my patch I made some benchmarks for clean b43, patched b43 and wl 5.100.82.38. See the charts for results. -
Support for N-PHYs rev 3+ in b43
There are two major code paths needed to support 802.11n Broadcom devices. First is for N-PHY revisions 1 and 2, second for 3 and higher.
As the first step we implemented support for PHYs 1 and 2. However I've just published patches enabling support for revision 3 and higher. Hopefully it will be just in time for 2.6.38 :)
Such a little Christmas gift from me ;)
[PATCH] b43: N-PHY: enable support for PHYs rev 3 and higher -
Broadcom 802.11n support in b43
I've started hacking on b43 about a year ago when I got my [del]BCM4328[/del] BCM4321 as Christmas gift. Unfortunately after few months of programming I've lost access to notebook where I put this card and couln't develop b43 anymore. That way you didn't see any N-PHY b43 commits until... Francesco Gringoli appeared and offered me ssh access to machine with his [del]BCM4328[/del] BCM4321 :)
Today, after a lot of fixes and improvements I finally found the last issue that stopped card from receiving! It appeared we were missing single N-PHY-specific bit in common path in b43. After fixing that I finally saw scanning results and Francesco succesfully tested associating to open network!
Please note, all this work was only possible thanks to Larry Finger who created great specifications as result of his reverse engineering efforts! -
radeon KMS HDMI for r7xx coming soon
I've just played some music over HDMI using radeon KMS and RV730 card! My local patch rewrites the way we choose HDMI block for encoder, drops current [em]hacks[/em] and make it work on more hardware. Plus of course it adds some single bits for DCE 3.2 GPUs. It needs some cleaning, splitting maybe and fixing resume. I hope to post it in day or two, hopefully in time for getting it into 2.6.34 :)