kern/58452: NCR5380 SCSI fixes for aborting transfers. BlueSCSI(v2)

[nahaialsloss%yahoo.com.au@localhost]

>Number:         58452
>Category:       kern
>Synopsis:       NCR5380 SCSI fixes for aborting transfers. BlueSCSI(v2)
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Mon Jul 22 02:45:00 +0000 2024
>Originator:     Nat Sloss
>Release:        NetBSD-10.0 apples to -9 and -current
>Organization:
NetBSD
>Environment:
NetBSD princess 10.99.10 NetBSD 10.99.10 (WSFBPWR) #12: Tue Oct 17 12:38:18 AEDT 2023  build@microrusty:/home/build/nbsd10/sys/arch/mac68k/compile/WSFBPWR mac68k
>Description:
With the use of dse(4) present in BlueSCSI(v2) and Rascsi devices,
aborting transfers are more frequent which can lead to a panic.


The problem stems from the fact that the transfers can take a reentrant fast patch, which makes it difficult to abort from.


>How-To-Repeat:
Everyday use of SCSISBC kernel and dse(4). can cause a panic.

>Fix:
I'll upload a patch in a follow up email.

There are four components to the patch:

1. No more fast path for transfers.  The old api is still there for drivers that use it safely.

2. Abort messages are printed with only DEBUG enabled as there are harmless.

3.  Medium errors follow the normal retry path.

4.  Existing transfers are aborted on scsi bus reset.

With these changes the system (Powerbook 160) has performed very well.

Filing this under kern as its scope is greater than mac68k.

Best regards,

Nat