[MinnowBoard] Need to disable both UART on LSE?

[Lucas De Marchi]

On Wed, Apr 29, 2015 at 6:12 PM, Darren Hart <dvhart at linux.intel.com> wrote:
> On 4/29/15, 1:35 PM, "Lucas De Marchi" <lucas.de.marchi at gmail.com> wrote:
>
>>Hi John,
>>
>>On Wed, Apr 29, 2015 at 3:25 PM, John Hawley <john.hawley at intel.com>
>>wrote:
>>> I assume all you are trying to do is flip the UARTs over to GPIO, this
>>> can be done in the bios configuration menu here:
>>>
>>> http://elinux.org/Minnowboard:MaxBios#LPSS_.26_SCC_Configuration
>>>
>>> you'll notice
>>>
>>> * LPSS 1 Configuration
>>> ** LPSS HSUART #1 Support
>>> ** LPSS HSUART #1 FlowCtrl
>>> ** LPSS HSUART #2 Support
>>>
>>> Just flip them to disabled and the GPIO pins should work as you are
>>> expecting.
>>
>>Yeah I saw that works but I'd like to use the other UART.  Do I really
>>need to disable both?
>>
>>Ideally I could even use UART1 if I just disabled FlowCtrl.
>
> Correct. "Support" means the RX/TX signals are used for the UART, Disabled
> means GPIO.
> FlowCTRL refers to the CTS/RTS signals.

The thing I'm trying to say is that doing this doesn't work. I already
flipped the config in the bios and even then I can't use the GPIO.
Tested: kernel 3.19.5 with firmware 0.71, 0.77 and 0.79

So, I decided to check if it's a kernel regression, and it is... in
3.14.4  I can successfully export the pin as GPIO.  I'll try to bisect
this and check the offending commit. Tomorrow. If it's known to work
for a more recent kernel version, bisecting it would be much easier.

thanks

-- 
Lucas De Marchi