[PATCH v3 01/11] drm/i915: Add i915 perf infrastructure

[Chris Wilson]

On Tue, Aug 16, 2016 at 03:59:24PM +0100, Robert Bragg wrote:
>    On Mon, Aug 15, 2016 at 3:57 PM, Chris Wilson
>      Alternatively you could follow the standard pattern for read. Dare I ask
>      what is going to go into state that needs the obfuscation?
> 
>    I had dug around a bit when I was trying to decide how to handle the
>    corner cases here and found some precedent for prioritize reporting any
>    data copied over an error for a read().

Reporting completed bytes before the error is correct. I was referring
to going between passing the return value as a mixture of state and return,
when it just appears to be following the usual pattern of read(). i.e. I
could find anything to support why your internal read callback required
a different signature. It looks unusual, so I am expecting it to do
unusual things.
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre