Re: m68k v3.16 status update

[Michael Schmitz <schmitzmic@gmail.com>]

Hi Tuomas,

fair enough - I'll get the PIO code tested by forcing PIO transfers on
elgar, and submit the driver for review once that's done. Maybe
someone else has a chance to test the fix in the meantime.

Cheers,

  Michael


On Fri, Dec 15, 2017 at 1:07 AM, Vainikka Tuomas
<tuomas.vainikka@aalto.fi> wrote:
> Hello,
>
> I do have the hardware, but unfortunately I do not have the time to test it.
>
> -Tuomas
> ________________________________________
> From: linux-m68k-owner@vger.kernel.org <linux-m68k-owner@vger.kernel.org> on behalf of Michael Schmitz <schmitzmic@gmail.com>
> Sent: 14 December 2017 06:47
> To: Tuomas Vainikka
> Cc: Geert Uytterhoeven; linux-m68k
> Subject: Re: m68k v3.16 status update
>
> Tuomas,
>
> are you still in the position to test tagged queue messages on Zorro ESP
> hardware?
>
> I've modified the Zorro ESP driver based on the work Finn Thain did for
> the Mac ESP driver (handling message in transfer by PIO, with special
> handshaking provisions for the message in case) and tried to test this
> on elgar (CyberStorm I ESP) but the original bug does not show up there.
> Might be to do with the SCSI disk used, or the CyberStorm I board.
>
> Might be better to test the new code on your hardware where we know the
> bug happened in the first place.
>
> Cheers,
>
>         Michael
>
> Am 09.08.2014 um 18:45 schrieb Tuomas Vainikka:
>> On 09.08.2014 01:25, Michael Schmitz wrote:
>>> Hi Tuomas,
>>>>>
>>>>> There's still the Amiga Zorro ESP patch out in limbo - DaveM
>>>>> suggested a change to enable SCSI-2 features to help with extended
>>>>> message bytes but that did not work as intended. Haven't had time to
>>>>> follow that one up. Tuomas' fix to the driver to bypass DMA for
>>>>> message in works OK though - do you want it submitted back to
>>>>> linux-scsi as is, or wait for a perfect solution (pun on me ...)?
>>>>>
>>>>>
>>>> Just to refresh your memory, the final fix was not to bypass DMA at
>>>> any level (I did that for the command transfer, but that didn't
>>>> help), but to have a dedicated slave_configure() function in the
>>>> Amiga Zorro ESP driver that would not enable TCQ.
>>>
>>> You guessed right about memory failing me - it wasn't about DMA in the
>>> end (for some reason, I seem to have DMA stuck in my mind at the
>>> moment), Do you see any other avenues to try and enable tagged
>>> commands in the ESP chip? We tried one config register only so far...
>>>
>> I think I've tested almost all possible register settings for the chip,
>> but it occurred to me that it is not enough to enable some chip features
>> by flipping bits. The code in esp_scsi would need to be modified to
>> handle the behaviour of these enabled features also.
>>
>> So, rethinking the code in esp_scsi would be one option.
>>
>> The second possibility is that I have a buggy chip in my setup. Removing
>> a sticker from my SCSI-board revealed the chip to be an AMD AM53CF94.
>> There are different versions of the SCSI-boards out there with different
>> chips; NCR, AMD, and QLogic, so if we had more people testing the driver
>> we would find out if the chip is actually the problem. (Is anyone even
>> testing the ISA/PCI cards that use esp_scsi?)
>>
>> Those are my suggestions at the TCQ problem.
>>
>> But do we really need TCQ?
>>
>> -Tuomas
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