Re: Alfa AWUS036ACM (Mediatek MT7612U) problem

[James <bjlockie@lockie.ca>]

On 2020-06-25 2:31 p.m., Alan Stern wrote:
> On Thu, Jun 25, 2020 at 01:08:34PM -0400, James wrote:
>> I have an Alfa AWUS036ACM (Mediatek MT7612U) on a Raspberry Pi 4. with:
>> OpenWrt SNAPSHOT r13626-751e6ab8e6 / LuCI Master git-20.175.45303-bb95e67
>> Kernel Version: 5.4.48
>>
>> # lsusb
>> Bus 002 Device 002: ID 0e8d:7612 MediaTek Inc.
>>
>> |My AP keeps dieing (I suspect when it's under load and some other condition
>> :-(). mt76x2u 2-1:1.0: error: mt76x02u_mcu_wait_resp failed with -110| I
>> tried:
>>
>> https://superuser.com/questions/176319/hard-reset-usb-in-ubuntu-10-04
> Did you try running the usbreset program described in that web page?
I don't have that program and I can't compile on that platform.
I tried the script instead of trying to cross compile.
>
>> cd /sys/bus/usb/drivers/usb
>>
>> echo 2-2 > unbind ; sleep 3 ; echo 2-2 > bind I think it should be 2-1 so I
>> tried that:
>>
>> echo 2-1 > unbind ; sleep 3 ; echo 2-1 > bind
>>
>> |[ 3539.309730] mt76x2u 2-1:1.0: firmware upload failed: -110
>> [ 3540.828260] mt76x2u: probe of 2-1:1.0 failed with error -5|
>> That didn't work.
>> Physically removing reinserting works (if I also "reset" the wifi in OpenWrt
>> (I don't know what this does)).
>>
>> There must be a way to remove/reinsert in software instead of rebooting.
> Well no, actually there isn't.  Removing a cable breaks the power
> connection; if the device gets its power from the USB cable then it goes
> through a complete shutdown (and restart when you plug it back in).  On
> most computers and USB hubs, there is no way to turn off power to the USB
> ports in software -- the hardware simply won't do it.  _Some_ hubs can
> turn off port power, but most can't.
>
> It is possible to do various sorts of reset in software, such as by using
> the usbreset program mentioned above.  But none of them do exactly the
> same thing as unplugging and replugging the USB cable.
>
> Alan Stern
I guess I'll have to reboot if it loses the AP.
I can automate that. :-)