On 01/26/2015 10:31 PM, Benjamin Herrenschmidt wrote:

On Mon, 2015-01-26 at 17:36 -0600, Brian King wrote:

quoted

To set some context, this function is only used by ipr for some old
broken adapters. These are adapters that are not supported on p8,
so will never show up under OPAL, only PowerVM. I'm fine with looking
at alternatives for the future, but I can't say I'm too excited about
changing the calling requirements for an API that has been around
for many years. Particularly given that this code is only needed for
these old adapters. If its difficult to implement this for OPAL without
noticeable delays, could we just return -EINVAL for this function on OPAL?,
since its not needed there today anyway.

Because it's needed for other things nowadays afaik, though IPR is the only one
that needs this to be done at interrupt time...

I'd argue we are our own worst enemy here really. The new user is EEH code.
I don't see a huge reason that code would need to use this exact same API.

In fact, even with IPR and the existing call, how do you wait for the link to come
back for a PERST ? That can take a while...

Basically, I assert reset, delay for 1/2 second via a timer interrupt, deassert reset,
delay for 2 seconds via another timer interrupt, then proceed with adapter initialization.

Thanks,

Brian

-- 
Brian King
Power Linux I/O
IBM Linux Technology Center