linux-kernel - [PATCH 4/5] drm/msm/dpu: add icc voting in dpu_mdss

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Message-Id: <20190618202425.15259-5-robdclark@gmail.com>
Date:   Tue, 18 Jun 2019 13:24:12 -0700
From:   Rob Clark <robdclark@...il.com>
To:     dri-devel@...ts.freedesktop.org
Cc:     linux-arm-msm@...r.kernel.org, Sean Paul <seanpaul@...omium.org>,
        Georgi Djakov <georgi.djakov@...aro.org>,
        Abhinav Kumar <abhinavk@...eaurora.org>,
        Sean Paul <sean@...rly.run>,
        Rob Clark <robdclark@...omium.org>,
        Rob Clark <robdclark@...il.com>,
        David Airlie <airlied@...ux.ie>,
        Daniel Vetter <daniel@...ll.ch>,
        Jordan Crouse <jcrouse@...eaurora.org>,
        Jayant Shekhar <jshekhar@...eaurora.org>,
        Stephen Boyd <swboyd@...omium.org>,
        Jeykumar Sankaran <jsanka@...eaurora.org>,
        freedreno@...ts.freedesktop.org, linux-kernel@...r.kernel.org
Subject: [PATCH 4/5] drm/msm/dpu: add icc voting in dpu_mdss_init

From: Abhinav Kumar <abhinavk@...eaurora.org>

dpu_mdss_destroy() can get called not just from
msm_drm_uninit() but also from msm_drm_bind() in case
of any failures.

dpu_mdss_destroy() removes the icc voting by calling
icc_put. This could accidentally remove the voting
done by pm_runtime_enable.

To make the voting balanced add a minimum vote in
dpu_mdss_init() to avoid any unclocked access.

This change depends on the following patch which
introduces interconnect binding to MDSS driver:

https://patchwork.codeaurora.org/patch/708155/

Signed-off-by: Abhinav Kumar <abhinavk@...eaurora.org>
Reviewed-by: Sean Paul <sean@...rly.run>
Signed-off-by: Rob Clark <robdclark@...omium.org>
---
 drivers/gpu/drm/msm/disp/dpu1/dpu_mdss.c | 18 ++++++++++++++----
 1 file changed, 14 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_mdss.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_mdss.c
index b1d0437ac7b6..986915bbbc02 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_mdss.c
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_mdss.c
@@ -49,6 +49,16 @@ static int dpu_mdss_parse_data_bus_icc_path(struct drm_device *dev,
 	return 0;
 }
 
+static void dpu_mdss_icc_request_bw(struct msm_mdss *mdss)
+{
+	struct dpu_mdss *dpu_mdss = to_dpu_mdss(mdss);
+	int i;
+	u64 avg_bw = dpu_mdss->num_paths ? MAX_BW / dpu_mdss->num_paths : 0;
+
+	for (i = 0; i < dpu_mdss->num_paths; i++)
+		icc_set_bw(dpu_mdss->path[i], avg_bw, kBps_to_icc(MAX_BW));
+}
+
 static void dpu_mdss_irq(struct irq_desc *desc)
 {
 	struct dpu_mdss *dpu_mdss = irq_desc_get_handler_data(desc);
@@ -160,11 +170,9 @@ static int dpu_mdss_enable(struct msm_mdss *mdss)
 {
 	struct dpu_mdss *dpu_mdss = to_dpu_mdss(mdss);
 	struct dss_module_power *mp = &dpu_mdss->mp;
-	int ret, i;
-	u64 avg_bw = dpu_mdss->num_paths ? MAX_BW / dpu_mdss->num_paths : 0;
+	int ret;
 
-	for (i = 0; i < dpu_mdss->num_paths; i++)
-		icc_set_bw(dpu_mdss->path[i], avg_bw, kBps_to_icc(MAX_BW));
+	dpu_mdss_icc_request_bw(mdss);
 
 	ret = msm_dss_enable_clk(mp->clk_config, mp->num_clk, true);
 	if (ret)
@@ -277,6 +285,8 @@ int dpu_mdss_init(struct drm_device *dev)
 
 	pm_runtime_enable(dev->dev);
 
+	dpu_mdss_icc_request_bw(priv->mdss);
+
 	pm_runtime_get_sync(dev->dev);
 	dpu_mdss->hwversion = readl_relaxed(dpu_mdss->mmio);
 	pm_runtime_put_sync(dev->dev);
-- 
2.20.1