Re: [Bug 8366] aic79xx and aic7xxx driver issues

[James Bottomley <James.Bottomley@SteelEye.com>]

On Thu, 2007-07-26 at 16:00 -0400, Freels, James D. wrote:
> 9) the output from the commands you asked for are shown below for the
> 2.6.22.1 kernel.  They indicate parity errors on the changer at scsi
> id=3.  Also, when booting up under 2.6.18.8, the linux media changer
> scsi device works and initializes; when booting up under 2.6.22.1, it
> does not; probably because of the same parity errors ?
> 
>  target0:0:3: Beginning Domain Validation
>  target0:0:3: asynchronous
>  target0:0:3: FAST-20 WIDE SCSI 40.0
                        ^^^^
This is the problem.

Something in the transport class is causing WIDE to be set regardless of
the max_width setting ... this looks to be a bug in the aic7xxx
transport class implementation

>  MB/s ST (50 ns, offset 32)
> (scsi0:A:3:0): parity error detected in Data-in phase. SEQADDR(0x1a6)
> SCSIRATE(0x95)

Once it goes wide on a narrow device, you get immediate parity errors
half the time, because you're missing the upper 8 bits for the parity
calculation.

I'll see if I can trace this inside the driver ... naturally, I have no
aic7xxx setup where I only have a narrow device.

James