[Dev] Chromebook C201 wifi

Josh Branning lovell.joshyyy at gmail.com
Sun Mar 31 20:24:37 GMT 2019

This is interesting, a while back I tried plugging in an external HDD to 
an olinuxino (ARM) using parabola, and it didn't get enough power 
either. At that point, I assumed it was because the board wasn't 
providing the right power through the USB. I was using a power pack that 
matched the recommended input voltage and current of the board.

Possibly a different thing entirely, but you never know ... there could 
be some setting in the kernel or bootloader or something that means the 
devices are only getting limited power through the USBs.

Another way to test if it is a parabola issue, could be to burn a live 
CD or make a usb of a different distro, and see if the adapter works 
with that, though if it is solely a bootloader issue, I guess that 
wouldn't be much help less a alternate one is also supplied. It is 
something I didn't do, because I assumed it would have probably been the 
hardware simply being not able to supply required the power.

Note that on some other less-free similar dev boards, USB hdds worked, 
albeit with a different distro. I know fosho that on some of these 
boards there is a bootloader setting where you can adjust the output 
current/voltage, so there may be one in u-boot too.



On 31/03/19 20:43, Lee Strobel wrote:
> lsusb for the Senao EUB9801 says its max power is 450mA, so only 50mA
> less than the Atheros. However, I suspect those are just numbers
> someone's typed in a text file somewhere. They might not actually be
> drawing those currents.
> It looks like a USB tester can be purchased online for $10. For that
> money, I might just buy one and actually measure the current draw.
> Btw, from what I saw on Wikipedia, it looks like a standard usb 2.0
> port should be able to supply 500mA as standard.
> Lee
> On Sun, 2019-03-31 at 14:04 -0400, Lee Strobel wrote:
>> Hi Denis,
>>> For the record, the WiFi related bugreport is here:
>>> https://labs.parabola.nu/issues/2261
>>> Could you try to see if a USB HUB that is powered by its own power
>>> supply makes it usable. If you don't have one you may know people
>>> that
>>> have one and borrow it just for doing a quick test.
>> I will see what I can do. I can't think of anyone I know off-hand who
>> would have an externally-powered USB hub, but I will ask around.
>> About the power thing: I actually have an older USB wifi dongle, a
>> 'Senao EUB9801', which seems to work great when plugged directly into
>> the Chromebook (if I use the firmware blob). According to the kernel
>> boot log, I think it is running on a Ralink chip of some kind. I will
>> try to investigate, as you suggested, and see if it requires less
>> power
>> than the ThinkPenguin dongle. It is older (~8-10 years), so maybe it
>> is
>> using an older wifi technology that consumes less power?
>> The reason I asked about the kernel devs is just because I was
>> wondering if the team that maintains the module for the Atheros chip
>> are aware of the issue. I would think we might need their assistance,
>> if any of us wanted to try to modify the module.
>> Lee
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