[Intel-gfx] [PATCH] drm/i915: fix i9xx irq enable/disable

[Chris Wilson]

Quoting Daniele Ceraolo Spurio (2019-03-29 16:41:55)
> 
> 
> On 3/29/19 9:32 AM, Chris Wilson wrote:
> > Quoting Daniele Ceraolo Spurio (2019-03-29 16:19:00)
> >> Those functions are used on gen4 as well and gen4 does have a non-RCS
> >> engine, so remove the BUG_ON and flip back the logic to what it was
> >> before the ENGINE_READ/WRITE update
> > 
> > Oh, silly me, gm45.
> >   
> >> Fixes: baba6e572b38 ("drm/i915: take a reference to uncore in the engine and use it")
> >> Signed-off-by: Daniele Ceraolo Spurio <daniele.ceraolospurio at intel.com>
> >> Cc: Chris Wilson <chris at chris-wilson.co.uk>
> >> Cc: Paulo Zanoni <paulo.r.zanoni at intel.com>
> >> ---
> >>   drivers/gpu/drm/i915/intel_ringbuffer.c | 10 +++-------
> >>   drivers/gpu/drm/i915/intel_ringbuffer.h |  1 +
> >>   2 files changed, 4 insertions(+), 7 deletions(-)
> >>
> >> diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
> >> index 48ba4d61a4ae..586e75c9edf3 100644
> >> --- a/drivers/gpu/drm/i915/intel_ringbuffer.c
> >> +++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
> >> @@ -976,20 +976,16 @@ gen5_irq_disable(struct intel_engine_cs *engine)
> >>   static void
> >>   i9xx_irq_enable(struct intel_engine_cs *engine)
> >>   {
> >> -       GEM_BUG_ON(engine->id != RCS0);
> >> -
> >>          engine->i915->irq_mask &= ~engine->irq_enable_mask;
> >> -       ENGINE_WRITE(engine, RING_IMR, engine->i915->irq_mask);
> >> -       ENGINE_POSTING_READ(engine, RING_IMR);
> >> +       intel_uncore_write(engine->uncore, IMR, engine->i915->irq_mask);
> >> +       ENGINE_POSTING_READ_FW(engine, RING_IMR);
> > 
> > But now we are posting something else on vcs0. Make it an
> > intel_uncore_posting_read_fw(engine->uncore, IMR) to match.
> > -Chris
> > 
> 
> I thought so as well, but the pre-rework code did:
> 
>         POSTING_READ_FW(RING_IMR(engine->mmio_base));
> 
> So I matched that.

Go for that second fix with one patch. What could possibly go wrong?
-Chris