drm/msm: gpu: Return error on hw_init failure

When the GPU hardware init function fails (like say, ME_INIT timed
out) return error instead of blindly continuing on. This gives us
a small chance of saving the system before it goes boom.
Signed-off-by: Jordan Crouse <jcrouse@codeaurora.org>
Signed-off-by: Rob Clark <robdclark@gmail.com>

drivers/gpu/drm/msm/adreno/a3xx_gpu.c

@@ -41,7 +41,7 @@ extern bool hang_debug;
 
 static void a3xx_dump(struct msm_gpu *gpu);
 
-static void a3xx_me_init(struct msm_gpu *gpu)
+static bool a3xx_me_init(struct msm_gpu *gpu)
 {
 	struct msm_ringbuffer *ring = gpu->rb;
 
@@ -65,7 +65,7 @@ static void a3xx_me_init(struct msm_gpu *gpu)
 	OUT_RING(ring, 0x00000000);
 
 	gpu->funcs->flush(gpu);
-	gpu->funcs->idle(gpu);
+	return gpu->funcs->idle(gpu);
 }
 
 static int a3xx_hw_init(struct msm_gpu *gpu)
@@ -294,9 +294,7 @@ static int a3xx_hw_init(struct msm_gpu *gpu)
 	/* clear ME_HALT to start micro engine */
 	gpu_write(gpu, REG_AXXX_CP_ME_CNTL, 0);
 
-	a3xx_me_init(gpu);
-
-	return 0;
+	return a3xx_me_init(gpu) ? 0 : -EINVAL;
 }
 
 static void a3xx_recover(struct msm_gpu *gpu)
@@ -337,17 +335,22 @@ static void a3xx_destroy(struct msm_gpu *gpu)
 	kfree(a3xx_gpu);
 }
 
-static void a3xx_idle(struct msm_gpu *gpu)
+static bool a3xx_idle(struct msm_gpu *gpu)
 {
 	/* wait for ringbuffer to drain: */
-	adreno_idle(gpu);
+	if (!adreno_idle(gpu))
+		return false;
 
 	/* then wait for GPU to finish: */
 	if (spin_until(!(gpu_read(gpu, REG_A3XX_RBBM_STATUS) &
-			A3XX_RBBM_STATUS_GPU_BUSY)))
+			A3XX_RBBM_STATUS_GPU_BUSY))) {
 		DRM_ERROR("%s: timeout waiting for GPU to idle!\n", gpu->name);
 
-	/* TODO maybe we need to reset GPU here to recover from hang? */
+		/* TODO maybe we need to reset GPU here to recover from hang? */
+		return false;
+	}
+
+	return true;
 }
 
 static irqreturn_t a3xx_irq(struct msm_gpu *gpu)

drivers/gpu/drm/msm/adreno/a4xx_gpu.c

@@ -113,7 +113,7 @@ static void a4xx_enable_hwcg(struct msm_gpu *gpu)
 }
 
 
-static void a4xx_me_init(struct msm_gpu *gpu)
+static bool a4xx_me_init(struct msm_gpu *gpu)
 {
 	struct msm_ringbuffer *ring = gpu->rb;
 
@@ -137,7 +137,7 @@ static void a4xx_me_init(struct msm_gpu *gpu)
 	OUT_RING(ring, 0x00000000);
 
 	gpu->funcs->flush(gpu);
-	gpu->funcs->idle(gpu);
+	return gpu->funcs->idle(gpu);
 }
 
 static int a4xx_hw_init(struct msm_gpu *gpu)
@@ -292,9 +292,7 @@ static int a4xx_hw_init(struct msm_gpu *gpu)
 	/* clear ME_HALT to start micro engine */
 	gpu_write(gpu, REG_A4XX_CP_ME_CNTL, 0);
 
-	a4xx_me_init(gpu);
-
-	return 0;
+	return a4xx_me_init(gpu) ? 0 : -EINVAL;
 }
 
 static void a4xx_recover(struct msm_gpu *gpu)
@@ -335,17 +333,21 @@ static void a4xx_destroy(struct msm_gpu *gpu)
 	kfree(a4xx_gpu);
 }
 
-static void a4xx_idle(struct msm_gpu *gpu)
+static bool a4xx_idle(struct msm_gpu *gpu)
 {
 	/* wait for ringbuffer to drain: */
-	adreno_idle(gpu);
+	if (!adreno_idle(gpu))
+		return false;
 
 	/* then wait for GPU to finish: */
 	if (spin_until(!(gpu_read(gpu, REG_A4XX_RBBM_STATUS) &
-					A4XX_RBBM_STATUS_GPU_BUSY)))
+					A4XX_RBBM_STATUS_GPU_BUSY))) {
 		DRM_ERROR("%s: timeout waiting for GPU to idle!\n", gpu->name);
+		/* TODO maybe we need to reset GPU here to recover from hang? */
+		return false;
+	}
 
-	/* TODO maybe we need to reset GPU here to recover from hang? */
+	return true;
 }
 
 static irqreturn_t a4xx_irq(struct msm_gpu *gpu)

drivers/gpu/drm/msm/adreno/adreno_gpu.c

@@ -218,19 +218,18 @@ void adreno_flush(struct msm_gpu *gpu)
 	adreno_gpu_write(adreno_gpu, REG_ADRENO_CP_RB_WPTR, wptr);
 }
 
-void adreno_idle(struct msm_gpu *gpu)
+bool adreno_idle(struct msm_gpu *gpu)
 {
 	struct adreno_gpu *adreno_gpu = to_adreno_gpu(gpu);
 	uint32_t wptr = get_wptr(gpu->rb);
-	int ret;
 
 	/* wait for CP to drain ringbuffer: */
-	ret = spin_until(get_rptr(adreno_gpu) == wptr);
-
-	if (ret)
-		DRM_ERROR("%s: timeout waiting to drain ringbuffer!\n", gpu->name);
+	if (!spin_until(get_rptr(adreno_gpu) == wptr))
+		return true;
 
 	/* TODO maybe we need to reset GPU here to recover from hang? */
+	DRM_ERROR("%s: timeout waiting to drain ringbuffer!\n", gpu->name);
+	return false;
 }
 
 #ifdef CONFIG_DEBUG_FS

drivers/gpu/drm/msm/adreno/adreno_gpu.h

@@ -182,7 +182,7 @@ void adreno_recover(struct msm_gpu *gpu);
 void adreno_submit(struct msm_gpu *gpu, struct msm_gem_submit *submit,
 		struct msm_file_private *ctx);
 void adreno_flush(struct msm_gpu *gpu);
-void adreno_idle(struct msm_gpu *gpu);
+bool adreno_idle(struct msm_gpu *gpu);
 #ifdef CONFIG_DEBUG_FS
 void adreno_show(struct msm_gpu *gpu, struct seq_file *m);
 #endif

drivers/gpu/drm/msm/msm_gpu.h

@@ -50,7 +50,7 @@ struct msm_gpu_funcs {
 	void (*submit)(struct msm_gpu *gpu, struct msm_gem_submit *submit,
 			struct msm_file_private *ctx);
 	void (*flush)(struct msm_gpu *gpu);
-	void (*idle)(struct msm_gpu *gpu);
+	bool (*idle)(struct msm_gpu *gpu);
 	irqreturn_t (*irq)(struct msm_gpu *irq);
 	uint32_t (*last_fence)(struct msm_gpu *gpu);
 	void (*recover)(struct msm_gpu *gpu);