Re: [PATCH v9 15/15] drm/i915: Add deadline based boost support

["Ville Syrjälä" <ville.syrjala@linux.intel.com>]

On Fri, Mar 03, 2023 at 06:48:43AM -0800, Rob Clark wrote:
> On Fri, Mar 3, 2023 at 1:58 AM Tvrtko Ursulin
> <tvrtko.ursulin@linux.intel.com> wrote:
> >
> >
> > On 03/03/2023 03:21, Rodrigo Vivi wrote:
> > > On Thu, Mar 02, 2023 at 03:53:37PM -0800, Rob Clark wrote:
> > >> From: Rob Clark <robdclark@chromium.org>
> > >>
> > >
> > > missing some wording here...
> > >
> > >> v2: rebase
> > >>
> > >> Signed-off-by: Rob Clark <robdclark@chromium.org>
> > >> ---
> > >>   drivers/gpu/drm/i915/i915_request.c | 20 ++++++++++++++++++++
> > >>   1 file changed, 20 insertions(+)
> > >>
> > >> diff --git a/drivers/gpu/drm/i915/i915_request.c b/drivers/gpu/drm/i915/i915_request.c
> > >> index 7503dcb9043b..44491e7e214c 100644
> > >> --- a/drivers/gpu/drm/i915/i915_request.c
> > >> +++ b/drivers/gpu/drm/i915/i915_request.c
> > >> @@ -97,6 +97,25 @@ static bool i915_fence_enable_signaling(struct dma_fence *fence)
> > >>      return i915_request_enable_breadcrumb(to_request(fence));
> > >>   }
> > >>
> > >> +static void i915_fence_set_deadline(struct dma_fence *fence, ktime_t deadline)
> > >> +{
> > >> +    struct i915_request *rq = to_request(fence);
> > >> +
> > >> +    if (i915_request_completed(rq))
> > >> +            return;
> > >> +
> > >> +    if (i915_request_started(rq))
> > >> +            return;
> > >
> > > why do we skip the boost if already started?
> > > don't we want to boost the freq anyway?
> >
> > I'd wager Rob is just copying the current i915 wait boost logic.
> 
> Yup, and probably incorrectly.. Matt reported fewer boosts/sec
> compared to your RFC, this could be the bug

I don't think i915 calls drm_atomic_helper_wait_for_fences()
so that could explain something.

-- 
Ville Syrjälä
Intel