Re: [Qemu-devel] [PATCH 2/2] scsi: esp: Improve consistency of RSTAT, RSEQ, and RINTR

[Mark Cave-Ayland]

On 29/11/2018 19:00, Guenter Roeck wrote:

>> Thanks for the patch. I just gave it a quick test, and unfortunately my 
>> NextSTEP ISO
>> still hangs in the same place on boot :(
>>
> Too bad. Is it "same place" as with the first version of the patch, or
> "same place" as in upstream qemu ? That might be important, as the two patch
> versions behave differently (one caches RSTAT/RINTR/RSEQ, one defers command
> complete handling).

I'd say same place as in upstream QEMU, although again the exact location does 
vary
so I have to keep running it several times to get a feel for whether or not it 
is in
improvement.

>> Not sure if it helps, but attached is a simple trace backend log from 
>> "-trace 'esp*'"
>> from startup all the way to the point where the kernel hangs on boot whilst
>> enumerating the SCSI bus (it does seem to hang at random points in the bus
>> enumeration process).
>>
> This is interesting; yours seems to be a different problem. I don't see any
> command_complete_deferred traces in your log. I also don't see any suspicious
> activity between esp_raise_irq and esp_lower_irq.
> 
> Can you try tracing in singlethreaded mode ? Maybe that can help us finding
> the difference.

Attached are the "-trace 'esp*' -trace 'scsi*'" outputs for a bad (normal) boot 
and
good (single threaded) boot for comparison.


ATB,

Mark.

trace-bad.txt.xz
Description: application/xz

trace-good.txt.xz
Description: application/xz