Re: Trying to understand CAM (and the cciss driver)

On Thu, May 23, 2024, 7:20 AM Marek Zarychta <zarychtam@plan-b.pwste.edu.pl>
wrote:

> Dnia Thu, May 09, 2024 at 07:58:32PM +0200, Peter Eriksson napisał(a):
> > Hi,
> >
> > I’m trying to fix a bug in the cciss driver that has been there
> “forever” when using it with an HP H241 SAS HBA card.
> > The driver works fine when all (SAS, spinning rust) drives are behaving
> well, but when some of them are starting to go bad it often goes into spin
> and either hangs the kernel or panics. I’ve been trying to add
> instrumentation to it in order to pin-point the problem and have been
> attempting some workarounds (like clearing cr_complete since without that
> hack sometime the driver get many many non-busy repeated requests with the
> same “tag” and then It panics with:
> (...)
> >
> > - Any suggestions? (Probably not but I thought I’d ask anyway :-)
> >
>
> Hello Peter,
>
> I have no suggestion but a question. Does the panic happen with
> https://reviews.freebsd.org/D25155 applied ? I am using your patch from
> this review with a few drives. It's handy and still builds fine on
> 15-CURRENT.
>

I think he'll still get panics from that since his panics were from bugs in
the recovery code, i think, and that patch doesn't really change that code.
There may be more diagnostics produced from that code, so it may be worth
trying...

Warner

Cheers
>
> --
> Marek Zarychta
>
>