Re: [PATCH v2] TTY: serial, add pm function

[Rickard Andersson <rickard.andersson@stericsson.com>]

On 01/17/2013 03:32 AM, Greg KH wrote:
> On Thu, Jan 17, 2013 at 01:36:48AM +0100, Linus Walleij wrote:
>> On Wed, Jan 16, 2013 at 4:24 PM, Greg KH<gregkh@linuxfoundation.org>  wrote:
>>> On Wed, Jan 16, 2013 at 09:33:09AM +0100, Rickard Andersson wrote:
>>>> The bluetooth cg2900 driver is on its way towards "staging".
>>> Really?  I've never heard of it before, nor seen it, so how would I know
>>> this?
>> It's been posted twice, here is the last time:
>> http://marc.info/?l=linux-kernel&m=134873373526049&w=2
>>
>> You commented several times on it, but I know a lot of code
>> pass by your console.
> Heh, that's funny, I don't remember that at all, I think I now
> officially have no long-term memory about patches I review :)
>
>>>   And we really never want to change core kernel code for staging
>>> drivers, it's one of the requirements of staging code.
>> Hm OK but it's a quite straight-forward thing for anything
>> connected on a UART in an embedded system that is not just a
>> serial cable or something and wants to save power.
>>
>> Maybe we can augment some other driver for something sitting
>> on a uart as a proof-of-concept then.
> You know we don't add infrastructure if there is no in-kernel user, and
> some random patch that was sent months ago doesn't really count as a
> "user" given that it's not even being submitted here, and it wasn't
> referenced in the patch itself that added the api.
>
> Also, why does this driver need something that the hundreds of other
> serial drivers we have in-kernel today do not?  What makes it special
> over everything else?
>
> thanks,
>
> greg "I will not remember writing this email" k-h
Previously we have used a hack where baud rate was set to 0 using 
set_termios and when the baudrate was 0 clock was turned off to save 
current by the amba-pl011 driver. Now I try to do it in a cleaner way. 
An old discussion can be found here:

http://lists.infradead.org/pipermail/linux-arm-kernel/2010-November/031111.html