Re: [PATCH v3 3/3] drm/i915: Enable Resource Streamer state save/restore in HSW

Ville Syrjälä
2015-05-18T15:36:31Z

On Mon, May 18, 2015 at 11:31:56AM +0300, Abdiel Janulgue wrote:
> Also clarify comments on context size that the extra state for
> Resource Streamer is included.
>
> Suggested-by: Chris Wilson <chris@chris-wilson.co.uk>
> Signed-off-by: Abdiel Janulgue <abdiel.janulgue@linux.intel.com>
> ---
> drivers/gpu/drm/i915/i915_gem_context.c | 2 +-
> drivers/gpu/drm/i915/i915_reg.h | 3 ++-
> 2 files changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_gem_context.c b/drivers/gpu/drm/i915/i915_gem_context.c
> index f3e84c4..1db107a 100644
> --- a/drivers/gpu/drm/i915/i915_gem_context.c
> +++ b/drivers/gpu/drm/i915/i915_gem_context.c
> @@ -509,7 +509,7 @@ mi_set_context(struct intel_engine_cs *ring,
> }
>
> /* These flags are for resource streamer on HSW+ */
> - if (!IS_HASWELL(ring->dev) && INTEL_INFO(ring->dev)->gen < 8)
> + if (IS_HASWELL(ring->dev))
> flags |= (MI_SAVE_EXT_STATE_EN | MI_RESTORE_EXT_STATE_EN);

I don't get it. Previously we told the hardware to save the extended
context on !hsw, and now we don't. That doesn't seem correct to me.

>
>
> diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
> index 238bb25..3db0596 100644
> --- a/drivers/gpu/drm/i915/i915_reg.h
> +++ b/drivers/gpu/drm/i915/i915_reg.h
> @@ -2498,7 +2498,8 @@ enum skl_disp_power_wells {
> * valid. Now, docs explain in dwords what is in the context object. The full
> * size is 70720 bytes, however, the power context and execlist context will
> * never be saved (power context is stored elsewhere, and execlists don't work
> - * on HSW) - so the final size is 66944 bytes, which rounds to 17 pages.
> + * on HSW) - so the final size, including the extra state required for the
> + * Resource Streamer, is 66944 bytes, which rounds to 17 pages.
> */
> #define HSW_CXT_TOTAL_SIZE (17 * PAGE_SIZE)
> /* Same as Haswell, but 72064 bytes now. */
> --
> 1.9.1
>
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--
Ville Syrjälä
Intel OTC