From: Jordan Crouse <jcrouse@codeaurora.org>
Date: Thu, 27 Jul 2017 10:42:32 -0600
Subject: drm/msm: Turn off hardware clock gating before reading A5XX registers
Git-commit: a23cb3b52fec73b22671bac65356d8c55bf37706
Patch-mainline: v4.13-rc5
References: FATE#326289 FATE#326079 FATE#326049 FATE#322398 FATE#326166

On A5XX GPU hardware clock gating needs to be turned off before
reading certain GPU registers via AHB. Turn off HWCG before calling
adreno_show() to safely dump all the registers without a system hang.

Signed-off-by: Jordan Crouse <jcrouse@codeaurora.org>
Signed-off-by: Rob Clark <robdclark@gmail.com>
Acked-by: Petr Tesarik <ptesarik@suse.com>
---
 drivers/gpu/drm/msm/adreno/a5xx_gpu.c |    7 +++++++
 1 file changed, 7 insertions(+)

--- a/drivers/gpu/drm/msm/adreno/a5xx_gpu.c
+++ b/drivers/gpu/drm/msm/adreno/a5xx_gpu.c
@@ -995,7 +995,14 @@ static void a5xx_show(struct msm_gpu *gp
 {
 	seq_printf(m, "status:   %08x\n",
 			gpu_read(gpu, REG_A5XX_RBBM_STATUS));
+
+	/*
+	 * Temporarily disable hardware clock gating before going into
+	 * adreno_show to avoid issues while reading the registers
+	 */
+	a5xx_set_hwcg(gpu, false);
 	adreno_show(gpu, m);
+	a5xx_set_hwcg(gpu, true);
 }
 #endif