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

From: Alan Cox
Date: Thu Oct 07 2010 - 16:40:23 EST


On Thu, 07 Oct 2010 13:36:06 -0700
Daniel Walker <dwalker@xxxxxxxxxxxxxx> 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
>
> Both what?

Both device allocations. Please use the 204,186 assigned for JTAG DCC.

> 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 !

We've said no over a period of about ten years to a lot of attempts to
just borrow the ttyS0 range. If we'd said yes it would have been a
complete mess by now.

So the answer is no.

Alan
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