Subject: Re: pc532 back, ethernet working!
To: None <>
From: Phil Budne <>
List: port-pc532
Date: 07/23/1996 12:27:21
> Have you considered putting this in the kernel as an MI SCSI target driver?

Yes, of course. But I wanted to figure out how to make it _work_
first! This was much easier to debug. There is a section of notes at
the end of the README file on my thoughts on the matter.

The tricky thing is that SCSI requests are almost always made
synchronously via physio, from a process context (the cd and sd
drivers do keep a queue, but there is still a waiting process). You
can make async SCSI requests, with a callback, but only if you have a
disk buffer, and acquiring a disk buffer can mean sleeping.  To poll
the ethernet box from a timeout, it may be necessary to avois physio()
and create "private" disk buffers (and make sure they're never freed).
As I said; tricky.