Re: ESP SCSI driver

[Michael Schmitz <schmitzmic@gmail.com>]

Hi Kars,

On 30/10/19 12:52 AM, Kars de Jong wrote:
> Hi Finn,
>
> Op di 29 okt. 2019 om 00:38 schreef Finn Thain <fthain@telegraphics.com.au>:
>> On Mon, 28 Oct 2019, Kars de Jong wrote:
>>> It probably uses a different chip. The text and images show it's a
>>> QLogic FAS216 (which is the same as a FAS236, FAS236 is the differential
>>> variant). The type should more accurately be presented as "FAS2x6" since
>>> you can't tell which type it is in software.
>>>
>> FWIW, the old driver, removed in commit a2c6ef71364e ("[SCSI] NCR53C9x:
>> remove driver", has this:
>>
>> -               if(family_code == 0x02) {
>> -                       if ((version & 7) == 2)
>> -                               esp->erev = fas216;
>> -                        else
>> -                               esp->erev = fas236;
> The fas236 type was from the original Sun-only esp driver (I guess the
> only Suns with a FAS2x6 had differential variants hence the name). I
> got a confirmation for the detection of the FAS216 from someone with a
> Cyberstorm board, so that one was added then (including the specific
> match on version). Since the NCR53C9x driver was never used on a Sun,
> this was never confirmed for the FAS236.

Do we need to distinguish between fas216 and fas236 at all? From the old 
driver code, they would seem to behave just the same.

Making use of the distinction between fsc and fas236 for enabling active 
negation would not require figuring out the SCSI bus mode (differential 
or single-ended) from my reading of the data book. Enabling back to back 
transfers might requrire more work on the driver.

Cheers,

     Michael


>
> Kind regards,
>
> Kars.