Re: [PATCH] serial: DCC(JTAG) serial and console emulation support

Mike Frysinger
2010-10-07T21:04:28Z

On Thu, Oct 7, 2010 at 16:51, Daniel Walker wrote:
> On Thu, 2010-10-07 at 22:05 +0100, Alan Cox wrote:
>> On Thu, 07 Oct 2010 13:36:06 -0700 Daniel Walker wrote:
>> > On Thu, 2010-10-07 at 21:50 +0100, Alan Cox wrote:
>> > > > +         Say Y here if you want to install DCC driver as a normal serial port
>> > > > +         /dev/ttyS0 (major 4, minor 64). Otherwise, it appears as /dev/ttyJ0
>> > > > +         (major 4, minor 128) and can co-exist with other UARTs, such as
>> > > > +         8250/16C550 compatibles.
>> > > > +
>> > >
>> > > NAK to both
>> >
>> > I would agree if this wasn't strictly for debugging embedded devices in
>> > difficult situations.. After talking to Mike, it's seems like it would
>> > be useful to have this as a ttyS* specifically because embedded devices
>> > won't always create a ttyJ* for you and ttyS* will likely already exist.
>>
>> If you are debugging an embedded device you are capable of changing it
>> (otherwise you wouldn't debug it). Therefore the fact you might need to
>> tweak the tty creation on the device is not a problem. If you can't
>> change the device well there is no point debugging it is there !
>
> Your making too many assumptions .. You might be able to modify the
> kernel, and not the userspace. So you couldn't tweak the device
> creation .. It's much easier in the server world ..

this driver isnt in the kernel. there is no ABI to preserve. if
people want to use the mainline driver, they can fix their userspace.
i dont think the "binary userspace" argument is terribly relevant to
new driver submissions.
-mike