Linux 2.6 MPT fusion bug

Linux 2.6 MPT fusion bug

[Hubert Tonneau]

I reported a fiew days ago Linux 2.6 not booting with no error message
on a Dell PowerEdge 2600.

I've just tracked the problem down to a faulty SCSI cable raising a bug in MTP
fusion driver for Linux kernel 2.6, up to Linux 2.6.6-rc2

Basically, one of the SCSI cable is wrong, probably a broken wire, so the BIOS
sais that it's a narrow cable, and switches down to 40 MB/s instead of 320 MB/s

With a 2.4 kernel, the Linux driver will report a fiew such error message:
<4>SCSI Error: (1:5:0) Status=02h (CHECK CONDITION)
<4> Key=6h (UNIT ATTENTION); FRU=02h
<4> ASC/ASCQ=29h/02h "SCSI BUS RESET OCCURRED"
<4> CDB: 28 00 00 00 18 3F 00 00 08 00
and recover gracefully, and the machine works perfectly, just a little bit
slower since the disks are connected at 40 MB/s.

With 2.6, the kernel with just hang immediately with absolutely no error message.

If I change the faulty cable, both Linux 2.4 and 2.6 will run perfectly.