serial: of-serial: fetch line number from DT

[Olof Johansson]

On Mon, Nov 10, 2014 at 1:38 PM, Stephen Warren <swarren at wwwdotorg.org> wrote:
> On 11/10/2014 02:34 PM, Olof Johansson wrote:
>>
>> Greg,
>>
>> This commit:
>>
>> commit 1bd8324535ec1ff44aef55c0e40b9e7d56b310fb
>> Author: Lucas Stach <dev at lynxeye.de>
>> Date:   Mon Nov 3 23:16:54 2014 +0100
>>
>>      serial: of-serial: fetch line number from DT
>
> ...
>>
>> Broke a whole lot of tegra boards in last night's -next here. In
>> particular, I've been looking at tegra20-seaboard, which now doesn't
>> boot with console any more.
>>
>> http://arm-soc.lixom.net/bootlogs/next/next-20141110/
>>
>> Unfortunately, tegra has for a long time been specifying the aliases
>> as a fixed 1:1 mapping, but most environments rely on ttyS0 being the
>> first _activated_ serial port. That's obviously going to break things
>> here. :(
>
> ...
>>
>> Stephen: I suppose the best way to handle this on tegra is to specify
>> the aliases per-board instead of in the soc dtsi today.
>
>
> IIRC, there was a deliberate request to name the Tegra UARTs after the SoC
> ports rather than board ports, so that it'd be obvious to people which port
> was which. I'm not sure if we can change the aliases in the Tegra DTs now
> that people may have got used to them?

I think that's a great idea in general, but they've been this way now
for 4 years and it'll mean everyone changing bootargs and console
configurations (where to spawn getty) everywhere. :(


-Olof