linux-kernel - [PATCH] media: cedrus: Fix clock/reset sequence

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Message-ID: <20230911184612.1754373-1-jernej.skrabec@gmail.com>
Date:   Mon, 11 Sep 2023 20:46:12 +0200
From:   Jernej Skrabec <jernej.skrabec@...il.com>
To:     mripard@...nel.org, paul.kocialkowski@...tlin.com
Cc:     mchehab@...nel.org, gregkh@...uxfoundation.org, wens@...e.org,
        samuel@...lland.org, linux-media@...r.kernel.org,
        linux-staging@...ts.linux.dev,
        linux-arm-kernel@...ts.infradead.org, linux-sunxi@...ts.linux.dev,
        linux-kernel@...r.kernel.org,
        Jernej Skrabec <jernej.skrabec@...il.com>
Subject: [PATCH] media: cedrus: Fix clock/reset sequence

According to H6 user manual, resets should always be de-asserted before
clocks are enabled. This is also consistent with vendor driver.

Fixes: d5aecd289bab ("media: cedrus: Implement runtime PM")
Signed-off-by: Jernej Skrabec <jernej.skrabec@...il.com>
---
 .../staging/media/sunxi/cedrus/cedrus_hw.c    | 24 +++++++++----------
 1 file changed, 12 insertions(+), 12 deletions(-)

diff --git a/drivers/staging/media/sunxi/cedrus/cedrus_hw.c b/drivers/staging/media/sunxi/cedrus/cedrus_hw.c
index b696bf884cbd..32af0e96e762 100644
--- a/drivers/staging/media/sunxi/cedrus/cedrus_hw.c
+++ b/drivers/staging/media/sunxi/cedrus/cedrus_hw.c
@@ -172,12 +172,12 @@ int cedrus_hw_suspend(struct device *device)
 {
 	struct cedrus_dev *dev = dev_get_drvdata(device);
 
-	reset_control_assert(dev->rstc);
-
 	clk_disable_unprepare(dev->ram_clk);
 	clk_disable_unprepare(dev->mod_clk);
 	clk_disable_unprepare(dev->ahb_clk);
 
+	reset_control_assert(dev->rstc);
+
 	return 0;
 }
 
@@ -186,11 +186,18 @@ int cedrus_hw_resume(struct device *device)
 	struct cedrus_dev *dev = dev_get_drvdata(device);
 	int ret;
 
+	ret = reset_control_reset(dev->rstc);
+	if (ret) {
+		dev_err(dev->dev, "Failed to apply reset\n");
+
+		return ret;
+	}
+
 	ret = clk_prepare_enable(dev->ahb_clk);
 	if (ret) {
 		dev_err(dev->dev, "Failed to enable AHB clock\n");
 
-		return ret;
+		goto err_rst;
 	}
 
 	ret = clk_prepare_enable(dev->mod_clk);
@@ -207,21 +214,14 @@ int cedrus_hw_resume(struct device *device)
 		goto err_mod_clk;
 	}
 
-	ret = reset_control_reset(dev->rstc);
-	if (ret) {
-		dev_err(dev->dev, "Failed to apply reset\n");
-
-		goto err_ram_clk;
-	}
-
 	return 0;
 
-err_ram_clk:
-	clk_disable_unprepare(dev->ram_clk);
 err_mod_clk:
 	clk_disable_unprepare(dev->mod_clk);
 err_ahb_clk:
 	clk_disable_unprepare(dev->ahb_clk);
+err_rst:
+	reset_control_assert(dev->rstc);
 
 	return ret;
 }
-- 
2.42.0