Messages in this thread |  | | | From | Ondrej Zary <> | | Subject | Re: [rt2x00-users] [PATCH RFC] rt2500usb: disable broken HW encryption by default | | Date | Tue, 23 Mar 2010 16:09:56 +0100 |
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On Tuesday 23 March 2010, Ivo Van Doorn wrote: > On Tue, Mar 23, 2010 at 10:27 AM, Ondrej Zary > > <linux@rainbow-software.org> wrote: > > On Monday 22 March 2010, Ivo Van Doorn wrote: > >> >> But I though it was mentioned that disabling HW crypto didn't solve > >> >> the issue due to a second bug in a later kernel? > >> > > >> > That was a false positive. Probably because the device was not > >> > unplugged between the tests (and looks like the driver does not > >> > initialize the chip completely). It's not reliable, it sometimes stops > >> > working after reboot. > >> > >> Ah well that at least simplifies the problem. I'll have to retest > >> rt2500usb soon to see why the HW crypto failed. I am sure I had it > >> working for WEP, WPA and WPA2 > >> before I submitted the patch. > > > > So let's try to fix it instead of disabling. > > > > First, the unrealiability (keeping HW encryption disabled). With the > > driver loaded but not doing anything more, the register dumps are same > > for both working and non-working case (dump-init.txt). > > > > dump-good-connected.txt is a dump after successful association and DHCP > > dump-bad-attempt.txt is a dump after successful association during > > non-working DHCP attempt > > dump-bad-after.txt is a dump after DHCP timed out > > With association working, but DHCP failing it most likely means that > somehow the frame was malformatted. > The code for HW crypto alters the frame (alters IV/EIV/ICV data etc). > And that is commonly the source of > problems, because what has to be done depends heavily on the encryption > type. > > So could you verify which of the encryption types (WEP,WPA,WPA2) is > failing or working? That would give a starting > position on which bytes might be corrupted.
I was testing only with WPA2 before. I did some more testing today. The results:
No encryption - works always WEP - sometimes works, sometimes not - same with and without HW encryption WPA - sometimes works, sometimes not - same with and without HW encryption WPA2 - never works with HW encryption - sometimes works, sometimes not without HW encryptionn
So it seems that there are two problems: 1. random problems with any encryption 2. WPA2 is broken with HW encryption
When the "random" problem appears, this appears in dmesg: wlan1: authenticate with 00:13:d4:0f:f3:17 (try 1) wlan1: authenticated wlan1: associate with 00:13:d4:0f:f3:17 (try 1) wlan1: RX AssocResp from 00:13:d4:0f:f3:17 (capab=0x411 status=0 aid=2) wlan1: associated phy0 -> rt2500usb_set_device_state: Error - Device failed to enter state 3 (-16). phy0 -> rt2500usb_set_device_state: Error - Device failed to enter state 3 (-16). No probe response from AP 00:13:d4:0f:f3:17 after 500ms, disconnecting.
Disabling call to rt2500usb_set_state() in rt2500usb_set_device_state() seems to fix problem 1. After this change, WEP and WPA work always regardless of HW encryption (and WPA2 works always without it).
-- Ondrej Zary
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