From 0d44d3fa2b9089b0039118351773d465204ad581 Mon Sep 17 00:00:00 2001 From: Alex Dai Date: Tue, 22 Sep 2015 13:48:40 -0700 Subject: [PATCH] drm/i915/guc: Fix a bug in GuC status check Bit 16 of GuC status indicates resuming from RC6. The LAPIC_DONE status is a reliable readiness flag only when resuming from RC6. This fix a racing issue that allocation of doorbell fails whilst GuC init is not finished. Signed-off-by: Alex Dai Reviewed-by: Sagar Arun Kamble Signed-off-by: Daniel Vetter --- drivers/gpu/drm/i915/i915_guc_reg.h | 1 + drivers/gpu/drm/i915/intel_guc_loader.c | 5 +++-- 2 files changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_guc_reg.h b/drivers/gpu/drm/i915/i915_guc_reg.h index 9d79a6b7cc2f..b35566164c4d 100644 --- a/drivers/gpu/drm/i915/i915_guc_reg.h +++ b/drivers/gpu/drm/i915/i915_guc_reg.h @@ -37,6 +37,7 @@ #define GS_UKERNEL_READY (0xF0 << GS_UKERNEL_SHIFT) #define GS_MIA_SHIFT 16 #define GS_MIA_MASK (0x07 << GS_MIA_SHIFT) +#define GS_MIA_CORE_STATE (1 << GS_MIA_SHIFT) #define SOFT_SCRATCH(n) (0xc180 + ((n) * 4)) diff --git a/drivers/gpu/drm/i915/intel_guc_loader.c b/drivers/gpu/drm/i915/intel_guc_loader.c index e0601cc5a795..40241f37e24b 100644 --- a/drivers/gpu/drm/i915/intel_guc_loader.c +++ b/drivers/gpu/drm/i915/intel_guc_loader.c @@ -209,9 +209,10 @@ static inline bool guc_ucode_response(struct drm_i915_private *dev_priv, u32 *status) { u32 val = I915_READ(GUC_STATUS); + u32 uk_val = val & GS_UKERNEL_MASK; *status = val; - return ((val & GS_UKERNEL_MASK) == GS_UKERNEL_READY || - (val & GS_UKERNEL_MASK) == GS_UKERNEL_LAPIC_DONE); + return (uk_val == GS_UKERNEL_READY || + ((val & GS_MIA_CORE_STATE) && uk_val == GS_UKERNEL_LAPIC_DONE)); } /* -- 2.39.2