[rt2x00-users] rt2800pci & hw crypto

Ivo Van Doorn ivdoorn at gmail.com
Tue Jun 1 00:10:09 AEST 2010


> I saw you also merged a patch to enable hw crypto by default on rt2800pci.

Well it isn't merged into master. I keep it in my experimental tree for now.
I managed to get some devices working on it with the WPA/WPA2 network,
but only once, (During a second test, none of the devices could
connect to the AP).

However performance was a bit low, since I experience "hickups",
at some moments, packets weren't being send out, but hold for a number
of seconds
before bursting out of the device.

With ping this meant that the response time could sometimes increase
to 5 seconds,
where in some cases the ping failed because the queue was flooded. When normal
operation restored ping response time reduced to a couple of milliseconds.

I still have to test on a WEP network though.

> The patch doesn't break anything but unfortunately it seems that hw crypto
> doesn't work for received frames (only tried rt3052 SoC as usual) and
> mac80211 decrypts them in sw.

Actually I didn't test that part yet. So I can't confirm the same for
the rt2770 devices.

> So, I agree that we can simply turn hwcrypto on by default as it seems that
> encrypting tx frames works just fine but we still have to investigate why
> rx decryption fails.

Well the reason why it defaulted to off, was that it simply didn't work before.
It can be switched to on, if we can have a connection and transfer
data. Which is the
case apparently, since mac80211 can SW decrypt frames anyway...

> Btw. I checked if rx decryption works by printing out RXD_W3_DECRYPTED for every
> rx frame and it was never set :(

I'll test that out for the rt2770 devices, and see if WEP is also working.

If that is the case, I'll submit the patch for merger into the master branch.


More information about the users mailing list