Re: [PATCH 1/3] drm/i915: Enable resource streamer bits on MI_BATCH_BUFFER_START

Chris Wilson
2015-06-08T17:55:31Z

On Mon, Jun 08, 2015 at 08:42:20PM +0300, Abdiel Janulgue wrote:
>
>
> On 06/08/2015 07:10 PM, Ville Syrjälä wrote:
> > On Mon, Jun 08, 2015 at 01:04:07PM +0300, Abdiel Janulgue wrote:
> >> Adds support for executing the resource streamer on BDW and HSW
> >>
> >> v2: Add support for Execlists (Minu Mathai <minu.mathai@intel.com>)
> >>
> >> Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
> >> Signed-off-by: Abdiel Janulgue <abdiel.janulgue@linux.intel.com>
> >> ---
> >> drivers/gpu/drm/i915/i915_reg.h | 1 +
> >> drivers/gpu/drm/i915/intel_lrc.c | 4 +++-
> >> drivers/gpu/drm/i915/intel_ringbuffer.c | 8 ++++++--
> >> drivers/gpu/drm/i915/intel_ringbuffer.h | 1 +
> >> 4 files changed, 11 insertions(+), 3 deletions(-)
> >>
> >> diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
> >> index b522eb6..238bb25 100644
> >> --- a/drivers/gpu/drm/i915/i915_reg.h
> >> +++ b/drivers/gpu/drm/i915/i915_reg.h
> >> @@ -356,6 +356,7 @@
> >> #define MI_BATCH_BUFFER_START MI_INSTR(0x31, 0)
> >> #define MI_BATCH_GTT (2<<6) /* aliased with (1<<7) on gen4 */
> >> #define MI_BATCH_BUFFER_START_GEN8 MI_INSTR(0x31, 1)
> >> +#define MI_BATCH_RESOURCE_STREAMER (1<<10)
> >>
> >> #define MI_PREDICATE_SRC0 (0x2400)
> >> #define MI_PREDICATE_SRC1 (0x2408)
> >> diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
> >> index fcb074b..3b168f6 100644
> >> --- a/drivers/gpu/drm/i915/intel_lrc.c
> >> +++ b/drivers/gpu/drm/i915/intel_lrc.c
> >> @@ -1172,7 +1172,9 @@ static int gen8_emit_bb_start(struct intel_ringbuffer *ringbuf,
> >> return ret;
> >>
> >> /* FIXME(BDW): Address space and security selectors. */
> >> - intel_logical_ring_emit(ringbuf, MI_BATCH_BUFFER_START_GEN8 | (ppgtt<<8));
> >> + intel_logical_ring_emit(ringbuf, MI_BATCH_BUFFER_START_GEN8 |
> >> + (ppgtt<<8) | (I915_DISPATCH_RS ?
> >
> > That doesn't look right.
>
> Yay.. Didn't catch these since this path never gets executed under GEN8
> anyway which uses execlist not legacy batch buffer execution. Better
> remove this then.

Which makes gen8 support conditional and so needs reflecting in the
interface.

Just test the flag correctly.
-Chris

--
Chris Wilson, Intel Open Source Technology Centre