[Intel-gfx] [PATCH 05/11] drm/i915/execlists: Process one CSB interrupt at a time

[Chris Wilson]

Quoting Tvrtko Ursulin (2018-06-04 15:27:34)
> 
> On 31/05/2018 19:51, Chris Wilson wrote:
> > In the next patch, we will process the CSB events directly from the CS
> > interrupt handler, being called for each interrupt. Hence, we will no
> 
> Correct to explain it is the user interrupt handler.

?

> > longer have the need for a loop until the has-interrupt bit is clear,
> > and in the meantime can remove that small optimisation.
> 
> Hm, isn't this assuming the optimistic csb processing from user 
> interrupt sees the event? If it doesn't, couldn't we still end up 
> needing the loop here?

No. We get the CS interrupt when hw updates the write pointer. (Not sure
if it's just the first write.)
-Chris