Re: [PATCH v3 -next 11/11] serial: 8250_early: Remove setup_early_serial8250_console()

Peter Hurley
2015-04-04T01:16:15Z

On 04/03/2015 08:52 PM, Yinghai Lu wrote:
> On Fri, Apr 3, 2015 at 11:27 AM, Peter Hurley <peter@hurleysoftware.com> wrote:
>> On 04/03/2015 01:44 PM, Yinghai Lu wrote:
>>> On Fri, Apr 3, 2015 at 10:38 AM, Peter Hurley <peter@hurleysoftware.com> wrote:
>>>> On 04/03/2015 12:57 PM, Yinghai Lu wrote:
>>>>
>>>> Wait -- you have earlycon in a product??
>>>
>>> What do you mean?
>>
>> I mean, what will happen if I put in a big debug banner like Steven
>> did for ftrace?
>>
>> Kernel developers need earlycon for debugging arch code; often the earlycon
>> is just hacked together especially when it requires fixmap support.
>>
>> Putting it in a product and _relying on undocumented behavior_ is a bad idea.
>
> let me repeat again:
> when you have "console=uart8250,io,0x3f8", you will have earlycon and
> then console.
>
> That is just for kernel developer for debugging.
>
> When you have x86 with bunch of dimms and cpus, user will have to wait couple
> of minutes to output from console=ttyS0....and if it hang early, no
> one would know what happen.
>
> Also it is only boot time only....

The fix is sitting in your inbox. Pointless to discuss it now.