From 950b2aaeea6960561425fc80adfb5b2fc0ac020f Mon Sep 17 00:00:00 2001 From: Tim Gore Date: Wed, 16 Mar 2016 16:13:46 +0000 Subject: [PATCH] drm/i915/gen9: add WaClearFlowControlGpgpuContextSave This allows writes to EU flow control registers. Together with SIP code from the user-mode driver this resolves a hang seen in some pre-emption scenarios. Note that this patch is just the kernel mode part of this workaround. v2. Oops, add FLOW_CONTROL_ENABLE macro to i915_reg.h. Signed-off-by: Tim Gore Reviewed-by: Arun Siluvery Signed-off-by: Tvrtko Ursulin Link: http://patchwork.freedesktop.org/patch/msgid/1458144826-17269-1-git-send-email-tim.gore@intel.com --- drivers/gpu/drm/i915/i915_reg.h | 1 + drivers/gpu/drm/i915/intel_ringbuffer.c | 2 ++ 2 files changed, 3 insertions(+) diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h index 07e04495cd9a..264885fc245d 100644 --- a/drivers/gpu/drm/i915/i915_reg.h +++ b/drivers/gpu/drm/i915/i915_reg.h @@ -7105,6 +7105,7 @@ enum skl_disp_power_wells { #define GEN9_CCS_TLB_PREFETCH_ENABLE (1<<3) #define GEN8_ROW_CHICKEN _MMIO(0xe4f0) +#define FLOW_CONTROL_ENABLE (1<<15) #define PARTIAL_INSTRUCTION_SHOOTDOWN_DISABLE (1<<8) #define STALL_DOP_GATING_DISABLE (1<<5) diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c index b7c8fc1a73a3..9c59ede5dd9a 100644 --- a/drivers/gpu/drm/i915/intel_ringbuffer.c +++ b/drivers/gpu/drm/i915/intel_ringbuffer.c @@ -925,8 +925,10 @@ static int gen9_init_workarounds(struct intel_engine_cs *engine) I915_WRITE(GAM_ECOCHK, I915_READ(GAM_ECOCHK) | ECOCHK_DIS_TLB); + /* WaClearFlowControlGpgpuContextSave:skl,bxt */ /* WaDisablePartialInstShootdown:skl,bxt */ WA_SET_BIT_MASKED(GEN8_ROW_CHICKEN, + FLOW_CONTROL_ENABLE | PARTIAL_INSTRUCTION_SHOOTDOWN_DISABLE); /* Syncing dependencies between camera and graphics:skl,bxt */ -- 2.45.2