linux-kernel - [PATCH] spi: rockchip: Avoid redundant clock disable in pm operation

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Message-Id: <20240824051452.3954878-1-jon.lin@rock-chips.com>
Date: Sat, 24 Aug 2024 13:14:52 +0800
From: Jon Lin <jon.lin@...k-chips.com>
To: briannorris@...omium.org,
	broonie@...nel.org
Cc: linux-rockchip@...ts.infradead.org,
	linux-kernel@...r.kernel.org,
	heiko@...ech.de,
	jon.lin@...k-chips.com,
	linux-arm-kernel@...ts.infradead.org,
	linux-spi@...r.kernel.org
Subject: [PATCH] spi: rockchip: Avoid redundant clock disable in pm operation

Fix WARN_ON:
[   22.869352][ T1885] clk_spi0 already unprepared
[   22.869379][ T1885] WARNING: CPU: 3 PID: 1885 at drivers/clk/clk.c:813 clk_core_unprepare+0xbc4
[   22.869380][ T1885] Modules linked in: bcmdhd dhd_static_buf
[   22.869391][ T1885] CPU: 3 PID: 1885 Comm: Binder:355_2 Tainted: G        W         5.10.66 #59
[   22.869393][ T1885] Hardware name: Rockchip RK3588 EVB1 LP4 V10 Board (DT)
[   22.869397][ T1885] pstate: 60400009 (nZCv daif +PAN -UAO -TCO BTYPE=--)
[   22.869401][ T1885] pc : clk_core_unprepare+0xbc/0x214
[   22.869404][ T1885] lr : clk_core_unprepare+0xbc/0x214

Fixes:  ("spi: rockchip: Suspend and resume the bus during NOIRQ_SYSTEM_SLEEP_PM ops")
Signed-off-by: Jon Lin <jon.lin@...k-chips.com>
---

 drivers/spi/spi-rockchip.c | 57 +++++++++++++++++---------------------
 1 file changed, 26 insertions(+), 31 deletions(-)

diff --git a/drivers/spi/spi-rockchip.c b/drivers/spi/spi-rockchip.c
index e1ecd96c7858..043a7739c330 100644
--- a/drivers/spi/spi-rockchip.c
+++ b/drivers/spi/spi-rockchip.c
@@ -940,33 +940,24 @@ static void rockchip_spi_remove(struct platform_device *pdev)
 	spi_controller_put(ctlr);
 }
 
-#ifdef CONFIG_PM_SLEEP
-static int rockchip_spi_suspend(struct device *dev)
+#ifdef CONFIG_PM
+static int rockchip_spi_runtime_suspend(struct device *dev)
 {
-	int ret;
 	struct spi_controller *ctlr = dev_get_drvdata(dev);
 	struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
 
-	ret = spi_controller_suspend(ctlr);
-	if (ret < 0)
-		return ret;
-
 	clk_disable_unprepare(rs->spiclk);
 	clk_disable_unprepare(rs->apb_pclk);
 
-	pinctrl_pm_select_sleep_state(dev);
-
 	return 0;
 }
 
-static int rockchip_spi_resume(struct device *dev)
+static int rockchip_spi_runtime_resume(struct device *dev)
 {
 	int ret;
 	struct spi_controller *ctlr = dev_get_drvdata(dev);
 	struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
 
-	pinctrl_pm_select_default_state(dev);
-
 	ret = clk_prepare_enable(rs->apb_pclk);
 	if (ret < 0)
 		return ret;
@@ -975,41 +966,45 @@ static int rockchip_spi_resume(struct device *dev)
 	if (ret < 0)
 		clk_disable_unprepare(rs->apb_pclk);
 
-	ret = spi_controller_resume(ctlr);
-	if (ret < 0) {
-		clk_disable_unprepare(rs->spiclk);
-		clk_disable_unprepare(rs->apb_pclk);
-	}
-
 	return 0;
 }
-#endif /* CONFIG_PM_SLEEP */
+#endif /* CONFIG_PM */
 
-#ifdef CONFIG_PM
-static int rockchip_spi_runtime_suspend(struct device *dev)
+#ifdef CONFIG_PM_SLEEP
+static int rockchip_spi_suspend(struct device *dev)
 {
+	int ret;
 	struct spi_controller *ctlr = dev_get_drvdata(dev);
-	struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
 
-	clk_disable_unprepare(rs->spiclk);
-	clk_disable_unprepare(rs->apb_pclk);
+	ret = spi_controller_suspend(ctlr);
+	if (ret < 0)
+		return ret;
+
+	/* Avoid redundant clock disable */
+	if (!pm_runtime_status_suspended(dev))
+		rockchip_spi_runtime_suspend(dev);
+
+	pinctrl_pm_select_sleep_state(dev);
 
 	return 0;
 }
 
-static int rockchip_spi_runtime_resume(struct device *dev)
+static int rockchip_spi_resume(struct device *dev)
 {
 	int ret;
 	struct spi_controller *ctlr = dev_get_drvdata(dev);
-	struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
 
-	ret = clk_prepare_enable(rs->apb_pclk);
-	if (ret < 0)
-		return ret;
+	pinctrl_pm_select_default_state(dev);
 
-	ret = clk_prepare_enable(rs->spiclk);
+	if (!pm_runtime_status_suspended(dev)) {
+		ret = rockchip_spi_runtime_resume(dev);
+		if (ret < 0)
+			return ret;
+	}
+
+	ret = spi_controller_resume(ctlr);
 	if (ret < 0)
-		clk_disable_unprepare(rs->apb_pclk);
+		rockchip_spi_runtime_suspend(dev);
 
 	return 0;
 }
-- 
2.34.1