From 1f6cca404918d2d3bc476afb31b371a406009c06 Mon Sep 17 00:00:00 2001
From: Akhil P Oommen <quic_akhilpo@quicinc.com>
Date: Fri, 19 Aug 2022 01:52:13 +0530
Subject: [PATCH] drm/msm/a6xx: Ensure CX collapse during gpu recovery

Because there could be transient votes from other drivers/tz/hyp which
may keep the cx gdsc enabled, we should poll until cx gdsc collapses.
We can use the reset framework to poll for cx gdsc collapse from gpucc
clk driver.

This feature requires support from the platform's gpucc driver.

Signed-off-by: Akhil P Oommen <quic_akhilpo@quicinc.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de>
Patchwork: https://patchwork.freedesktop.org/patch/498397/
Link: https://lore.kernel.org/r/20220819015030.v5.5.I176567525af2b9439a7e485d0ca130528666a55c@changeid
Signed-off-by: Rob Clark <robdclark@chromium.org>
---
 drivers/gpu/drm/msm/adreno/a6xx_gpu.c | 4 ++++
 drivers/gpu/drm/msm/msm_gpu.c         | 4 ++++
 drivers/gpu/drm/msm/msm_gpu.h         | 4 ++++
 3 files changed, 12 insertions(+)

diff --git a/drivers/gpu/drm/msm/adreno/a6xx_gpu.c b/drivers/gpu/drm/msm/adreno/a6xx_gpu.c
index aa2ec98613614..2ea5fb332df58 100644
--- a/drivers/gpu/drm/msm/adreno/a6xx_gpu.c
+++ b/drivers/gpu/drm/msm/adreno/a6xx_gpu.c
@@ -10,6 +10,7 @@
 
 #include <linux/bitfield.h>
 #include <linux/devfreq.h>
+#include <linux/reset.h>
 #include <linux/soc/qcom/llcc-qcom.h>
 
 #define GPU_PAS_ID 13
@@ -1297,6 +1298,9 @@ static void a6xx_recover(struct msm_gpu *gpu)
 	/* And the final one from recover worker */
 	pm_runtime_put_sync(&gpu->pdev->dev);
 
+	/* Call into gpucc driver to poll for cx gdsc collapse */
+	reset_control_reset(gpu->cx_collapse);
+
 	pm_runtime_use_autosuspend(&gpu->pdev->dev);
 
 	if (active_submits)
diff --git a/drivers/gpu/drm/msm/msm_gpu.c b/drivers/gpu/drm/msm/msm_gpu.c
index 9ec9a99ffe77a..0098ee8438aae 100644
--- a/drivers/gpu/drm/msm/msm_gpu.c
+++ b/drivers/gpu/drm/msm/msm_gpu.c
@@ -16,6 +16,7 @@
 #include <generated/utsrelease.h>
 #include <linux/string_helpers.h>
 #include <linux/devcoredump.h>
+#include <linux/reset.h>
 #include <linux/sched/task.h>
 
 /*
@@ -903,6 +904,9 @@ int msm_gpu_init(struct drm_device *drm, struct platform_device *pdev,
 	if (IS_ERR(gpu->gpu_cx))
 		gpu->gpu_cx = NULL;
 
+	gpu->cx_collapse = devm_reset_control_get_optional_exclusive(&pdev->dev,
+			"cx_collapse");
+
 	gpu->pdev = pdev;
 	platform_set_drvdata(pdev, &gpu->adreno_smmu);
 
diff --git a/drivers/gpu/drm/msm/msm_gpu.h b/drivers/gpu/drm/msm/msm_gpu.h
index a0885ff99e5bf..ff911e7305ce9 100644
--- a/drivers/gpu/drm/msm/msm_gpu.h
+++ b/drivers/gpu/drm/msm/msm_gpu.h
@@ -13,6 +13,7 @@
 #include <linux/interconnect.h>
 #include <linux/pm_opp.h>
 #include <linux/regulator/consumer.h>
+#include <linux/reset.h>
 
 #include "msm_drv.h"
 #include "msm_fence.h"
@@ -271,6 +272,9 @@ struct msm_gpu {
 	bool hw_apriv;
 
 	struct thermal_cooling_device *cooling;
+
+	/* To poll for cx gdsc collapse during gpu recovery */
+	struct reset_control *cx_collapse;
 };
 
 static inline struct msm_gpu *dev_to_gpu(struct device *dev)
-- 
2.30.2