Re: What's needed for PMP support?

[Mark Lord <liml@rtr.ca>]

Mark Lord wrote:
> Mark Lord wrote:
>..
>> We already have .pmp_scr_{read,write} operations.
>> If NULL, then default to the built-ins that are there now.
> ..
> 
> Mmm.. lost some lines there, try again:
> 
> We already have .scr_{read,write} operations, and
> what I think we need are .pmp_scr_{read,write} in addition.
> If NULL, then default to the built-ins that are there now.

Tejun Heo wrote:
> Adding ->sata_pmp_scr_read/write should do but I wanna avoid that if possible.
..

Well, what it really needed was .pmp_read() and .pmp_write().

I implemented that, and (finally!!) sata_mv works perfectly
with the Marvell port multiplier I have here.

All other attempts to do this entirely within sata_mv
just left me (and the hardware) dazed and confused.

But being able to wrap sata_pmp_read/write() with save/restore
logic fixed things enough to work on the first try.

Whew!

I'll post a summary patch once I get it generated here.
Lots of debug code to back out first.

Thanks Tejun, Saeed!