RE: 2.0.32: hard lockups with adaptec 2940U

Gerard Roudier (groudier@club-internet.fr)
Fri, 28 Nov 1997 00:29:41 +0100 (MET)


On Thu, 27 Nov 1997, Doug Ledford wrote:

> On 27-Nov-97 Chris Evans wrote:
> >
> >On Wed, 26 Nov 1997, Doug Ledford wrote:
> >
> >> You can find it at ftp.dialnet.net in /pub/linux/aic7xxx. There are
> >patches
> >> there for both the 2.0.31 and 2.0.32 kernel. We use 2.0.32 plus this
> >patch
> >> on things like our news server and other high load disk servers.
> >
> >Are these patches planned for 2.0.33? They sound important. Bear in mind
> >2.0.32 is our "flagship" kernel, and if it can't hand the world's most
> >popular SCSI card when put under a bit of load....
>
> I guess some people would say unfortunately, but no. They are not planned
> for inclusion. These patches are created by me and are designed to solve
> certain reliability issues in the current aic7xxx driver. However, Dan
> Eischen is the official aic7xxx maintainer. What goes in the kernel is what
> he releases. Some of the code in these patches he doesn't want in the
> official driver because it makes the job of porting newer versions of the
> driver from FreeBSD to linux more difficult. This is mainly true in areas
> where the FreeBSD mid level SCSI code handles certain situations on behalf
> of the low level driver and linux's mid level SCSI code doesn't.

Just for your information, if I had maintained the ncr53c8xx driver this
way neither Linux not FreeBSD would probably support features of new
SYMBIOS chip at the moment.
A driver is a small piece of code and so backporting changes is not that
hard in my opinion (and experience).
The only interesting question should be:
Is this change an improvement for Linux or not?
Any other consideration seems to me not relevant.

Here is a brief history of the ncr53c8xx driver:

** December 10 1995 by Gerard Roudier:
** Initial port to Linux.
**
** June 23 1996 by Gerard Roudier:
** Support for 64 bits architectures (Alpha).
**
** November 30 1996 by Gerard Roudier:
** Support for Fast-20 scsi.
** Support for large DMA fifo and 128 dwords bursting.
**
** February 27 1997 by Gerard Roudier:
** Support for Fast-40 scsi.
** Support for on-Board RAM.
**
** May 3 1997 by Gerard Roudier:
** Full support for scsi scripts instructions pre-fetching.
**
** May 19 1997 by Richard Waltham <dormouse@farsrobt.demon.co.uk>:
** Support for NvRAM detection and reading.
**
** August 18 1997 by Cort <cort@cs.nmt.edu>:
** Support for Power/PC (Big Endian).

I generally slightly rewrite changes that are submitted to me but does
not refuse them if they are interesting for Linux.

Regards, Gerard.