PPP2 driver interface_pp.c overhaul

[Peter Pregler]

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On 29-Aug-99 Peter Pregler wrote:
> 
> That is true. There is a busy-wait in the kernel-code (the WHILE_OUT macro).
> I
> have a patch that utilizes the scheduler task-queu. Note that
> interrupt-driven
> code is not the solution here. The busy wait is while waiting for data on the
> parallel port and not while waiting for a picture. Unfortunatly my code has
> still some problem if interrupted (I am new to kernel-hacking ;). I will
> debug
> this and than send the patch to the list. This should happen until Tuesday
> this
> week.

Okay, here is the patch as promised. The patch is against the original
cpia-0.2. It is using a timer and not a task queue but who cares. I was not able
to crash my machine anymore. So it might be stable. Use at your own risk and
don't assume it is SMP-safe. Has anyone a good description about programming
kernel-modules that are SMP-safe? That chapter is empty in the kernel-module
programming guide.

As for resource consumption: I had a closer look and the numbers were about 9%
in kernel mode for reading data and about 30% in user-mode decoding. All done
on a PII-350 with linux-2.2.12, size cif, thresholds set to 10, autocompression
resulting in about 4 fps. So there was pretty much data going over the parport.

Greetings, Peter

-------------------------------
Even the thought that a ship was waiting to take him back to Earth
did not wipe out the sense of loss he felt at that moment.
-------------------------------
Email: Peter.Pregler@risc.uni-linz.ac.at
Peter Pregler / RISC, University of Linz, Austria

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