linux-kernel - [PATCH 4.19 117/245] drm/msm/a5xx: Always set an OPP supported hardware value

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Date:   Tue, 29 Sep 2020 12:59:28 +0200
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org, Jordan Crouse <jcrouse@...eaurora.org>,
        Eric Anholt <eric@...olt.net>,
        Rob Clark <robdclark@...omium.org>,
        Sasha Levin <sashal@...nel.org>
Subject: [PATCH 4.19 117/245] drm/msm/a5xx: Always set an OPP supported hardware value

From: Jordan Crouse <jcrouse@...eaurora.org>

[ Upstream commit 0478b4fc5f37f4d494245fe7bcce3f531cf380e9 ]

If the opp table specifies opp-supported-hw as a property but the driver
has not set a supported hardware value the OPP subsystem will reject
all the table entries.

Set a "default" value that will match the default table entries but not
conflict with any possible real bin values. Also fix a small memory leak
and free the buffer allocated by nvmem_cell_read().

Signed-off-by: Jordan Crouse <jcrouse@...eaurora.org>
Reviewed-by: Eric Anholt <eric@...olt.net>
Signed-off-by: Rob Clark <robdclark@...omium.org>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 drivers/gpu/drm/msm/adreno/a5xx_gpu.c | 27 ++++++++++++++++++++-------
 1 file changed, 20 insertions(+), 7 deletions(-)

diff --git a/drivers/gpu/drm/msm/adreno/a5xx_gpu.c b/drivers/gpu/drm/msm/adreno/a5xx_gpu.c
index 1fc9a7fa37b45..d29a58bd2f7a3 100644
--- a/drivers/gpu/drm/msm/adreno/a5xx_gpu.c
+++ b/drivers/gpu/drm/msm/adreno/a5xx_gpu.c
@@ -1474,18 +1474,31 @@ static const struct adreno_gpu_funcs funcs = {
 static void check_speed_bin(struct device *dev)
 {
 	struct nvmem_cell *cell;
-	u32 bin, val;
+	u32 val;
+
+	/*
+	 * If the OPP table specifies a opp-supported-hw property then we have
+	 * to set something with dev_pm_opp_set_supported_hw() or the table
+	 * doesn't get populated so pick an arbitrary value that should
+	 * ensure the default frequencies are selected but not conflict with any
+	 * actual bins
+	 */
+	val = 0x80;
 
 	cell = nvmem_cell_get(dev, "speed_bin");
 
-	/* If a nvmem cell isn't defined, nothing to do */
-	if (IS_ERR(cell))
-		return;
+	if (!IS_ERR(cell)) {
+		void *buf = nvmem_cell_read(cell, NULL);
+
+		if (!IS_ERR(buf)) {
+			u8 bin = *((u8 *) buf);
 
-	bin = *((u32 *) nvmem_cell_read(cell, NULL));
-	nvmem_cell_put(cell);
+			val = (1 << bin);
+			kfree(buf);
+		}
 
-	val = (1 << bin);
+		nvmem_cell_put(cell);
+	}
 
 	dev_pm_opp_set_supported_hw(dev, &val, 1);
 }
-- 
2.25.1