From d9927abb4594ba940b3ed1dd86fa0447faf13a7b Mon Sep 17 00:00:00 2001 From: Matt Roper Date: Fri, 26 Aug 2022 14:02:33 -0700 Subject: [PATCH] Revert "drm/i915/dg2: Add preemption changes for Wa_14015141709" This reverts commit ca6920811aa5428270dd78af0a7a36b10119065a. The intent of Wa_14015141709 was to inform us that userspace can no longer control object-level preemption as it has on past platforms (i.e., by twiddling register bit CS_CHICKEN1[0]). The description of the workaround in the spec wasn't terribly well-written, and when we requested clarification from the hardware teams we were told that on the kernel side we should also probably stop setting FF_SLICE_CS_CHICKEN1[14], which is the register bit that directs the hardware to honor the settings in per-context register CS_CHICKEN1. It turns out that this guidance about FF_SLICE_CS_CHICKEN1[14] was a mistake; even though CS_CHICKEN1[0] is non-operational and useless to userspace, there are other bits in the register that do still work and might need to be adjusted by userspace in the future (e.g., to implement other workarounds that show up). If we don't set FF_SLICE_CS_CHICKEN1[14] in i915, then those future workarounds would not take effect. This miscommunication came to light because another workaround (Wa_16013994831) has now shown up that requires userspace to adjust the value of CS_CHICKEN[10] in certain circumstances. To ensure userspace's updates to this chicken bit are handled properly by the hardware, we need to make sure that FF_SLICE_CS_CHICKEN1[14] is once again set by the kernel. Signed-off-by: Matt Roper Reviewed-by: Matt Atwood Link: https://patchwork.freedesktop.org/patch/msgid/20220826210233.406482-1-matthew.d.roper@intel.com --- drivers/gpu/drm/i915/gt/intel_workarounds.c | 2 +- drivers/gpu/drm/i915/i915_drv.h | 3 --- 2 files changed, 1 insertion(+), 4 deletions(-) diff --git a/drivers/gpu/drm/i915/gt/intel_workarounds.c b/drivers/gpu/drm/i915/gt/intel_workarounds.c index 3cdb829..69a0c6a 100644 --- a/drivers/gpu/drm/i915/gt/intel_workarounds.c +++ b/drivers/gpu/drm/i915/gt/intel_workarounds.c @@ -2389,7 +2389,7 @@ rcs_engine_wa_init(struct intel_engine_cs *engine, struct i915_wa_list *wal) FF_DOP_CLOCK_GATE_DISABLE); } - if (HAS_PERCTX_PREEMPT_CTRL(i915)) { + if (IS_GRAPHICS_VER(i915, 9, 12)) { /* FtrPerCtxtPreemptionGranularityControl:skl,bxt,kbl,cfl,cnl,icl,tgl */ wa_masked_en(wal, GEN7_FF_SLICE_CS_CHICKEN1, diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h index 8feb4b2..66871be 100644 --- a/drivers/gpu/drm/i915/i915_drv.h +++ b/drivers/gpu/drm/i915/i915_drv.h @@ -1414,9 +1414,6 @@ IS_SUBPLATFORM(const struct drm_i915_private *i915, #define HAS_GUC_DEPRIVILEGE(dev_priv) \ (INTEL_INFO(dev_priv)->has_guc_deprivilege) -#define HAS_PERCTX_PREEMPT_CTRL(i915) \ - ((GRAPHICS_VER(i915) >= 9) && GRAPHICS_VER_FULL(i915) < IP_VER(12, 55)) - #define HAS_D12_PLANE_MINIMIZATION(dev_priv) (IS_ROCKETLAKE(dev_priv) || \ IS_ALDERLAKE_S(dev_priv)) -- 2.7.4