[LinuxPPS] http://lkml.org/lkml/2008/4/11/42

[Udo van den Heuvel]

Udo van den Heuvel wrote:
> Rodolfo Giometti wrote:
>> Currently not, sorry. Maybe looking at that "tty->ops" patch which
>> Alan talks about... I asked for an URL. Still waiting...
> 
> http://marc.info/?l=linux-kernel&m=120810871408144&w=2
> 
> ?

[PATCH] tty: The big operations rework

- Operations are now a shared const function block as with most other
Linux objects
- Introduce wrappers for some optional functions to get consistent
behaviour
- Wrap put_char which used to be patched by the tty layer
- Document which functions are needed/optional
- Make put_char report success/fail
- Cache the driver->ops pointer in the tty as tty->ops
- Remove various surplus lock calls we no longer need
- Remove proc_write method as noted by Alexey Dobriyan
- Introduce some missing sanity checks where certain driver/ldisc
combinations would oops as they didn't check needed methods were present

So what does this patch do for us?


BTW: Besides the 'x86 lowlevel irq way' of obtaining timestamps (which
works well), could we just duplicate the serial code to some extent and
use that copy for the PPS stuff?
This driver could be as minimal as we like.

(I doubt that idea will be accepted at the lkml...)

So what options do we have?

- Current approach
- Lowlevel x86-only irq method (works best for resolution)
- Copying the serial driver as I proposed above
- Alan's ldisc idea (how much does it differ?)
- ...

Please comment.