[BUG] brcmfmac: BRCM4354 cannot connect since commit 270a6c1f65

["S. Gilles" <sgilles@xxxxxxxxxxxx>]

Hi,

I have an Asus C201, which comes with a BRCM4354 (SDIO). On boot,
dmesg shows

    brcmfmac: brcmf_c_preinit_dcmds: Firmware version = wl0: Apr  8 2015 13:03:52 version 7.35.79.79 (r547158) FWID 01-7f29997a

Since 270a6c1f65fe68a28a5d39cd405592c550b496c7 (brcmfmac: rework
headroom check in .start_xmit()), the machine cannot connect to any
wireless network. I can fully reproduce this, and have bisected it;
I'm mailing this from the commit before: a833f3d4de. I only have
access to WPA2 networks, in case it matters. The relevent part of
dmesg from a bad boot is

    [    ...    ] IPv6: ADDRCONF(NETDEV_CHANGE): wlan0: link becomes ready
    [  +0.000767] brcmfmac: brcmf_proto_bcdc_hdrpull: wlan0: non-BCDC packet received, flags 0x0
    [  +0.905426] brcmfmac: brcmf_proto_bcdc_hdrpull: wlan0: non-BCDC packet received, flags 0x0
    [Jul11 11:02] brcmfmac: brcmf_proto_bcdc_hdrpull: wlan0: non-BCDC packet received, flags 0x0
    [  +0.983406] brcmfmac: brcmf_proto_bcdc_hdrpull: wlan0: non-BCDC packet received, flags 0x0
    [Jul11 11:03] brcmfmac: brcmf_proto_bcdc_hdrpull: wlan0: non-BCDC packet received, flags 0x0
    [Jul11 11:05] brcmfmac: brcmf_proto_bcdc_hdrpull: wlan0: non-BCDC packet received, flags 0x0
    [  +0.981930] brcmfmac: brcmf_proto_bcdc_hdrpull: wlan0: non-BCDC packet received, flags 0x0
    [Jul11 11:07] brcmfmac: brcmf_proto_bcdc_hdrpull: wlan0: non-BCDC packet received, flags 0x0
    [Jul11 11:09] brcmfmac: brcmf_proto_bcdc_hdrpull: wlan0: non-BCDC packet received, flags 0x0
    [  +0.698295] brcmfmac: brcmf_proto_bcdc_hdrpull: wlan0: non-BCDC packet received, flags 0x0
    ... (etc.)
    [  +0.918891] brcmfmac: brcmf_proto_bcdc_hdrpull: wlan0: non-BCDC packet received, flags 0x0
    [Jul11 11:18] dwmmc_rockchip ff0d0000.dwmmc: Successfully tuned phase to 204
    [ +12.545604] brcmfmac: brcmf_proto_bcdc_hdrpull: wlan0: non-BCDC packet received, flags 0x0
    ... (etc.)

meanwhile, wpa_cli is full of output like

    ...
    <3>CTRL-EVENT-NETWORK-NOT-FOUND
    <3>CTRL-EVENT-SCAN-STARTED
    <3>CTRL-EVENT-SCAN-RESULTS
    <3>CTRL-EVENT-SSID-REENABLED id=1 ssid="{known SSID}"
    <3>Trying to associate with SSID '{known SSID}'
    <3>Associated with {MAC}
    <3>CTRL-EVENT-SUBNET-STATUS-UPDATE status=0
    <3>Authentication with {MAC} timed out.
    <3>CTRL-EVENT-DISCONNECTED bssid={MAC} reason=3 locally_generated=1
    <3>WPA: 4-Way Handshake failed - pre-shared key may be incorrect
    <3>CTRL-EVENT-SID-TEMP-DISABLED id=1 ssid="{known SSID}" auth_failures=26 duration=120 reason=WRONG_KEY
    <3>CTRL-EVENT-REGDOM-CHANGE init=CORE type=WORLD
    <3>CTRL-EVENT-SCAN-STARTED
    <3>CTRL-EVENT-SCAN-RESULTS
    <4>Failed to initiate sched scan
    <3>CTRL-EVENT-NETWORK-NOT-FOUND
    ... 

The `non-BCDC packet received' messages in dmesg occur just before
the `timed out' messages in wpa_cli.

Please let me know if more information is needed of if there are
patches I should test.

-- 
S. Gilles