Re: sata_mv & pmp support

[Mark Lord <liml@rtr.ca>]

Tejun Heo wrote:
> Mark Lord wrote:
..
>> I've just noticed that, if I unplug/replug the host-side SATA cable
>> on the Sil3726 PM, and *then* "insmod sata_mv", the PM is not found.
>>
>> If I then simply do "rmmod sata_mv ; insmod sata_mv", then the PM is 
>> found.
>>
>> This happens with the original hardreset code from Jeff,
>> as well as the updated sata_mv code that I've posted earlier.
>> So it is not anything I've broken (recently :) ).
>>
>> Very strange.. I wonder if it also happens with the Marvell PM,
>> except I don't have one here to test with at the moment.
>>
>> Ever heard of anything strange like that?
> 
> IIRC, ICH8 ahci + 4726 fails the initial reset sequence because the PMP 
> comes up after the hardreset code times out, which triggers another EH 
> iteration which works out fine.  If the problem is caused by the PMP not 
> responding fast enough, it should cause a hotplug event afterwards. 
> Maybe there's a race condition where hotplug events can be lost?
..

Ah.. perhaps that could be it.  I've temporarily disabled the hotplug
detection in sata_mv, because it is broken at present and interfered
with PMP support during earlier testing.

It is next on the list of things to fix (this week, hopefully) as part
of the IRQ/EH handling overhaul in sata_mv.

But strange that the driver always finds it on a simple rmmod/insmod reload.

??