drm/msm/a6xx: Fix hangcheck for IFPC

From the hangcheck handler, KMD checks a few registers in GX
domain to see if the GPU made any progress. But it cannot access
those registers when IFPC is enabled. Since HW based hang detection
is pretty decent, lets rely on it instead of these registers when
IFPC is enabled.

Signed-off-by: Akhil P Oommen <[e-mail]>
Patchwork: https://patchwork.freedesktop.org/patch/673378/
Signed-off-by: Rob Clark <[e-mail]>

drivers/gpu/drm/msm/adreno/a6xx_gpu.c

···
 
 static bool a6xx_progress(struct msm_gpu *gpu, struct msm_ringbuffer *ring)
 {
-	struct msm_cp_state cp_state = {
+	struct msm_cp_state cp_state;
+	bool progress;
+
+	/*
+	 * With IFPC, KMD doesn't know whether GX power domain is collapsed
+	 * or not. So, we can't blindly read the below registers in GX domain.
+	 * Lets trust the hang detection in HW and lie to the caller that
+	 * there was progress.
+	 */
+	if (to_adreno_gpu(gpu)->info->quirks & ADRENO_QUIRK_IFPC)
+		return true;
+
+	cp_state = (struct msm_cp_state) {
 		.ib1_base = gpu_read64(gpu, REG_A6XX_CP_IB1_BASE),
 		.ib2_base = gpu_read64(gpu, REG_A6XX_CP_IB2_BASE),
 		.ib1_rem  = gpu_read(gpu, REG_A6XX_CP_IB1_REM_SIZE),
 		.ib2_rem  = gpu_read(gpu, REG_A6XX_CP_IB2_REM_SIZE),
 	};
-	bool progress;
 
 	/*
 	 * Adjust the remaining data to account for what has already been