[Intel-gfx] [PATCH] drm/i915/vlv: Added/removed Render specific Hw Workarounds for VLV
Goel, Akash
akash.goel at intel.com
Sun Jan 19 16:48:48 CET 2014
>> Frankly, I don't know much about these particular workarounds, but for bisecting any regressions it would probably be a good idea to split the patch per workaround touched.We have
Sorry for late response on this, actually we have done sufficient testing for this patch. Moreover these workarounds are applicable to VLV only & will not affect any other platforms.
So probably it can be pushed as it is without splitting.
Best Regards
Akash
-----Original Message-----
From: Jani Nikula [mailto:jani.nikula at linux.intel.com]
Sent: Thursday, January 09, 2014 5:56 PM
To: Goel, Akash; intel-gfx at lists.freedesktop.org
Cc: Goel, Akash
Subject: Re: [Intel-gfx] [PATCH] drm/i915/vlv: Added/removed Render specific Hw Workarounds for VLV
On Thu, 09 Jan 2014, akash.goel at intel.com wrote:
> From: akashgoe <akash.goel at intel.com>
>
> The following changes leads to stable behavior, especially when
> playing 3D Apps, benchmarks.
>
> Added 4 new rendering specific Workarounds 1.
> WaTlbInvalidateStoreDataBefore :-
> Before pipecontrol with TLB invalidate set,
> need 2 store data commands
> 2. WaReadAfterWriteHazard :-
> Send 8 store dword commands after flush
> for read after write hazard
> (HSD Gen6 bug_de 3047871)
> 3. WaVSThreadDispatchOverride
> Performance optimization - Hw will
> decide which half slice the thread
> will dispatch, May not be really needed
> for VLV, as its single slice
> 4. WaDisable_RenderCache_OperationalFlush
> Operational flush cannot be enabled on
> BWG A0 [Errata BWT006]
>
> Removed 3 workarounds as not needed for VLV+(B0 onwards) 1.
> WaDisableRHWOOptimizationForRenderHang
> 2. WaDisableL3CacheAging
> 3. WaDisableDopClockGating
>
> Modified the implementation of 1 workaround 1.
> WaDisableL3Bank2xClockGate
> Disabling L3 clock gating- MMIO 940c[25] = 1
>
> Modified the programming of 2 registers in render ring init function
> 1. GFX_MODE_GEN7 (Enabling TLB invalidate) 2. MI_MODE (Enabling MI
> Flush)
Frankly, I don't know much about these particular workarounds, but for bisecting any regressions it would probably be a good idea to split the patch per workaround touched.
BR,
Jani.
>
> Change-Id: Ib60f8dc7d2213552e498d588e1bba7eaa1a921ed
> Signed-off-by: akashgoe <akash.goel at intel.com>
> Signed-off-by: Akash Goel <akash.goel at intel.com>
> ---
> drivers/gpu/drm/i915/i915_reg.h | 3 ++
> drivers/gpu/drm/i915/intel_pm.c | 32 +++++++++++-------
> drivers/gpu/drm/i915/intel_ringbuffer.c | 58
> ++++++++++++++++++++++++++++++---
> 3 files changed, 77 insertions(+), 16 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_reg.h
> b/drivers/gpu/drm/i915/i915_reg.h index a699efd..d829754 100644
> --- a/drivers/gpu/drm/i915/i915_reg.h
> +++ b/drivers/gpu/drm/i915/i915_reg.h
> @@ -934,6 +934,9 @@
> #define ECO_GATING_CX_ONLY (1<<3)
> #define ECO_FLIP_DONE (1<<0)
>
> +#define GEN7_CACHE_MODE_0 0x07000 /* IVB+ only */
> +#define GEN7_RC_OP_FLUSH_ENABLE (1<<0)
> +
> #define CACHE_MODE_1 0x7004 /* IVB+ */
> #define PIXEL_SUBSPAN_COLLECT_OPT_DISABLE (1<<6)
>
> diff --git a/drivers/gpu/drm/i915/intel_pm.c
> b/drivers/gpu/drm/i915/intel_pm.c index 469170c..e4d220c 100644
> --- a/drivers/gpu/drm/i915/intel_pm.c
> +++ b/drivers/gpu/drm/i915/intel_pm.c
> @@ -4947,22 +4947,18 @@ static void valleyview_init_clock_gating(struct drm_device *dev)
> _MASKED_BIT_ENABLE(GEN7_MAX_PS_THREAD_DEP |
> GEN7_PSD_SINGLE_PORT_DISPATCH_ENABLE));
>
> - /* Apply the WaDisableRHWOOptimizationForRenderHang:vlv workaround. */
> - I915_WRITE(GEN7_COMMON_SLICE_CHICKEN1,
> - GEN7_CSC1_RHWO_OPT_DISABLE_IN_RCC);
> -
> - /* WaApplyL3ControlAndL3ChickenMode:vlv */
> - I915_WRITE(GEN7_L3CNTLREG1, I915_READ(GEN7_L3CNTLREG1) | GEN7_L3AGDIS);
> I915_WRITE(GEN7_L3_CHICKEN_MODE_REGISTER, GEN7_WA_L3_CHICKEN_MODE);
>
> + /* WaDisable_RenderCache_OperationalFlush
> + * Clear bit 0, so we do a AND with the mask
> + * to keep other bits the same */
> + I915_WRITE(GEN7_CACHE_MODE_0, (I915_READ(GEN7_CACHE_MODE_0) |
> + _MASKED_BIT_DISABLE(GEN7_RC_OP_FLUSH_ENABLE)));
> +
> /* WaForceL3Serialization:vlv */
> I915_WRITE(GEN7_L3SQCREG4, I915_READ(GEN7_L3SQCREG4) &
> ~L3SQ_URB_READ_CAM_MATCH_DISABLE);
>
> - /* WaDisableDopClockGating:vlv */
> - I915_WRITE(GEN7_ROW_CHICKEN2,
> - _MASKED_BIT_ENABLE(DOP_CLOCK_GATING_DISABLE));
> -
> /* This is required by WaCatErrorRejectionIssue:vlv */
> I915_WRITE(GEN7_SQ_CHICKEN_MBCUNIT_CONFIG,
> I915_READ(GEN7_SQ_CHICKEN_MBCUNIT_CONFIG) | @@ -4991,10 +4987,24
> @@ static void valleyview_init_clock_gating(struct drm_device *dev)
> GEN6_RCPBUNIT_CLOCK_GATE_DISABLE |
> GEN6_RCCUNIT_CLOCK_GATE_DISABLE);
>
> - I915_WRITE(GEN7_UCGCTL4, GEN7_L3BANK2X_CLOCK_GATE_DISABLE);
> + /* WaDisableL3Bank2xClockGate
> + * Disabling L3 clock gating- MMIO 940c[25] = 1
> + * Set bit 25, to disable L3_BANK_2x_CLK_GATING */
> + I915_WRITE(GEN7_UCGCTL4,
> + I915_READ(GEN7_UCGCTL4) | GEN7_L3BANK2X_CLOCK_GATE_DISABLE);
>
> I915_WRITE(MI_ARB_VLV, MI_ARB_DISPLAY_TRICKLE_FEED_DISABLE);
>
> + /* WaVSThreadDispatchOverride
> + * Hw will decide which half slice the thread will dispatch.
> + * May not be needed for VLV, as its a single slice */
> + I915_WRITE(GEN7_CACHE_MODE_0,
> + I915_READ(GEN7_FF_THREAD_MODE) &
> + (~GEN7_FF_VS_SCHED_LOAD_BALANCE));
> +
> + /* WaDisable4x2SubspanOptimization,
> + * Disable combining of two 2x2 subspans into a 4x2 subspan
> + * Set chicken bit to disable subspan optimization */
> I915_WRITE(CACHE_MODE_1,
> _MASKED_BIT_ENABLE(PIXEL_SUBSPAN_COLLECT_OPT_DISABLE));
>
> diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c
> b/drivers/gpu/drm/i915/intel_ringbuffer.c
> index 442c9a6..c9350a1 100644
> --- a/drivers/gpu/drm/i915/intel_ringbuffer.c
> +++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
> @@ -563,7 +563,9 @@ static int init_render_ring(struct intel_ring_buffer *ring)
> int ret = init_ring_common(ring);
>
> if (INTEL_INFO(dev)->gen > 3)
> - I915_WRITE(MI_MODE, _MASKED_BIT_ENABLE(VS_TIMER_DISPATCH));
> + if (!IS_VALLEYVIEW(dev))
> + I915_WRITE(MI_MODE,
> + _MASKED_BIT_ENABLE(VS_TIMER_DISPATCH));
>
> /* We need to disable the AsyncFlip performance optimisations in order
> * to use MI_WAIT_FOR_EVENT within the CS. It should already be @@
> -579,10 +581,17 @@ static int init_render_ring(struct intel_ring_buffer *ring)
> I915_WRITE(GFX_MODE,
> _MASKED_BIT_ENABLE(GFX_TLB_INVALIDATE_ALWAYS));
>
> - if (IS_GEN7(dev))
> - I915_WRITE(GFX_MODE_GEN7,
> - _MASKED_BIT_DISABLE(GFX_TLB_INVALIDATE_ALWAYS) |
> - _MASKED_BIT_ENABLE(GFX_REPLAY_MODE));
> + if (IS_GEN7(dev)) {
> + if (IS_VALLEYVIEW(dev)) {
> + I915_WRITE(GFX_MODE_GEN7,
> + _MASKED_BIT_ENABLE(GFX_REPLAY_MODE));
> + I915_WRITE(MI_MODE, I915_READ(MI_MODE) |
> + _MASKED_BIT_ENABLE(MI_FLUSH_ENABLE));
> + } else
> + I915_WRITE(GFX_MODE_GEN7,
> + _MASKED_BIT_DISABLE(GFX_TLB_INVALIDATE_ALWAYS) |
> + _MASKED_BIT_ENABLE(GFX_REPLAY_MODE));
> + }
>
> if (INTEL_INFO(dev)->gen >= 5) {
> ret = init_pipe_control(ring);
> @@ -2157,6 +2166,7 @@ int
> intel_ring_flush_all_caches(struct intel_ring_buffer *ring) {
> int ret;
> + int i;
>
> if (!ring->gpu_caches_dirty)
> return 0;
> @@ -2165,6 +2175,26 @@ intel_ring_flush_all_caches(struct intel_ring_buffer *ring)
> if (ret)
> return ret;
>
> + /* WaReadAfterWriteHazard*/
> + /* Send a number of Store Data commands here to finish
> + flushing hardware pipeline.This is needed in the case
> + where the next workload tries reading from the same
> + surface that this batch writes to. Without these StoreDWs,
> + not all of the data will actually be flushd to the surface
> + by the time the next batch starts reading it, possibly
> + causing a small amount of corruption.*/
> + ret = intel_ring_begin(ring, 4 * 12);
> + if (ret)
> + return ret;
> + for (i = 0; i < 12; i++) {
> + intel_ring_emit(ring, MI_STORE_DWORD_INDEX);
> + intel_ring_emit(ring, I915_GEM_HWS_SCRATCH_INDEX <<
> + MI_STORE_DWORD_INDEX_SHIFT);
> + intel_ring_emit(ring, 0);
> + intel_ring_emit(ring, MI_NOOP);
> + }
> + intel_ring_advance(ring);
> +
> trace_i915_gem_ring_flush(ring, 0, I915_GEM_GPU_DOMAINS);
>
> ring->gpu_caches_dirty = false;
> @@ -2176,6 +2206,24 @@ intel_ring_invalidate_all_caches(struct
> intel_ring_buffer *ring) {
> uint32_t flush_domains;
> int ret;
> + int i;
> +
> + /* WaTlbInvalidateStoreDataBefore*/
> + /* Before pipecontrol with TLB invalidate set, need 2 store
> + data commands (such as MI_STORE_DATA_IMM or MI_STORE_DATA_INDEX)
> + Without this, hardware cannot guarantee the command after the
> + PIPE_CONTROL with TLB inv will not use the old TLB values.*/
> + ret = intel_ring_begin(ring, 4 * 2);
> + if (ret)
> + return ret;
> + for (i = 0; i < 2; i++) {
> + intel_ring_emit(ring, MI_STORE_DWORD_INDEX);
> + intel_ring_emit(ring, I915_GEM_HWS_SCRATCH_INDEX <<
> + MI_STORE_DWORD_INDEX_SHIFT);
> + intel_ring_emit(ring, 0);
> + intel_ring_emit(ring, MI_NOOP);
> + }
> + intel_ring_advance(ring);
>
> flush_domains = 0;
> if (ring->gpu_caches_dirty)
> --
> 1.8.5.2
>
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--
Jani Nikula, Intel Open Source Technology Center
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