linux-kernel - [PATCH] [v4] spi: spi-zynqmp-gqspi: Fix runtime PM imbalance in zynqmp_qspi

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Message-Id: <20210415074644.24646-1-dinghao.liu@zju.edu.cn>
Date:   Thu, 15 Apr 2021 15:46:44 +0800
From:   Dinghao Liu <dinghao.liu@....edu.cn>
To:     dinghao.liu@....edu.cn, kjlu@....edu
Cc:     quanyang.wang@...driver.com, Mark Brown <broonie@...nel.org>,
        Michal Simek <michal.simek@...inx.com>,
        Naga Sureshkumar Relli <naga.sureshkumar.relli@...inx.com>,
        Shubhrajyoti Datta <shubhrajyoti.datta@...inx.com>,
        linux-spi@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
        linux-kernel@...r.kernel.org
Subject: [PATCH] [v4] spi: spi-zynqmp-gqspi: Fix runtime PM imbalance in zynqmp_qspi_probe

There is a PM usage counter decrement after zynqmp_qspi_init_hw()
without any refcount increment, which leads to refcount leak.Add
a refcount increment to balance the refcount. Also set
auto_runtime_pm to resume suspended spi controller.

Fixes: 9e3a000362aec ("spi: zynqmp: Add pm runtime support")
Signed-off-by: Dinghao Liu <dinghao.liu@....edu.cn>
---

Changelog:

v2: - Add a refcount increment to fix refcout leak instead of the
      refcount decrement on error.
      Set ctlr->auto_runtime_pm = true.

v3: - Add fix tag.
      Add a return value check against pm_runtime_get_sync().
      Move pm_runtime_{mark_last_busy & put_autosuspend} to the
      end of current function.

v4: - Add error message on failure of pm_runtime_get_sync().
---
 drivers/spi/spi-zynqmp-gqspi.c | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/drivers/spi/spi-zynqmp-gqspi.c b/drivers/spi/spi-zynqmp-gqspi.c
index c8fa6ee18ae7..38f3ddd3ea7c 100644
--- a/drivers/spi/spi-zynqmp-gqspi.c
+++ b/drivers/spi/spi-zynqmp-gqspi.c
@@ -1160,11 +1160,16 @@ static int zynqmp_qspi_probe(struct platform_device *pdev)
 	pm_runtime_set_autosuspend_delay(&pdev->dev, SPI_AUTOSUSPEND_TIMEOUT);
 	pm_runtime_set_active(&pdev->dev);
 	pm_runtime_enable(&pdev->dev);
+
+	ret = pm_runtime_get_sync(&pdev->dev);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "Failed to pm_runtime_get_sync: %d\n", ret);
+		goto clk_dis_all;
+	}
+
 	/* QSPI controller initializations */
 	zynqmp_qspi_init_hw(xqspi);
 
-	pm_runtime_mark_last_busy(&pdev->dev);
-	pm_runtime_put_autosuspend(&pdev->dev);
 	xqspi->irq = platform_get_irq(pdev, 0);
 	if (xqspi->irq <= 0) {
 		ret = -ENXIO;
@@ -1187,6 +1192,7 @@ static int zynqmp_qspi_probe(struct platform_device *pdev)
 	ctlr->mode_bits = SPI_CPOL | SPI_CPHA | SPI_RX_DUAL | SPI_RX_QUAD |
 			    SPI_TX_DUAL | SPI_TX_QUAD;
 	ctlr->dev.of_node = np;
+	ctlr->auto_runtime_pm = true;
 
 	ret = devm_spi_register_controller(&pdev->dev, ctlr);
 	if (ret) {
@@ -1194,9 +1200,13 @@ static int zynqmp_qspi_probe(struct platform_device *pdev)
 		goto clk_dis_all;
 	}
 
+	pm_runtime_mark_last_busy(&pdev->dev);
+	pm_runtime_put_autosuspend(&pdev->dev);
+
 	return 0;
 
 clk_dis_all:
+	pm_runtime_put_sync(&pdev->dev);
 	pm_runtime_set_suspended(&pdev->dev);
 	pm_runtime_disable(&pdev->dev);
 	clk_disable_unprepare(xqspi->refclk);
-- 
2.17.1