linux-kernel - [PATCH 2/2] media: imx-mipi-csis: Drop extra clock enable at probe()

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Date:   Wed, 22 Nov 2023 15:13:49 +0200
From:   Tomi Valkeinen <tomi.valkeinen@...asonboard.com>
To:     Kieran Bingham <kieran.bingham@...asonboard.com>,
        Rui Miguel Silva <rmfrfs@...il.com>,
        Laurent Pinchart <laurent.pinchart@...asonboard.com>,
        Martin Kepplinger <martink@...teo.de>,
        Purism Kernel Team <kernel@...i.sm>,
        Mauro Carvalho Chehab <mchehab@...nel.org>,
        Shawn Guo <shawnguo@...nel.org>,
        Sascha Hauer <s.hauer@...gutronix.de>,
        Pengutronix Kernel Team <kernel@...gutronix.de>,
        Fabio Estevam <festevam@...il.com>,
        NXP Linux Team <linux-imx@....com>
Cc:     linux-media@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
        linux-kernel@...r.kernel.org,
        Tomi Valkeinen <tomi.valkeinen@...asonboard.com>
Subject: [PATCH 2/2] media: imx-mipi-csis: Drop extra clock enable at
 probe()

The driver always enables the clocks at probe() and disables them only
at remove(). It is not clear why the driver does this, as it supports
runtime PM, and enables and disables the clocks in the runtime resume
and suspend callbacks. Also, in the case runtime PM is not available,
the driver calls the resume and suspend callbacks manually from probe()
and remove().

Drop the unnecessary clock enable, thus enabling the clocks only when
actually needed.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@...asonboard.com>
---
 drivers/media/platform/nxp/imx-mipi-csis.c | 13 ++-----------
 1 file changed, 2 insertions(+), 11 deletions(-)

diff --git a/drivers/media/platform/nxp/imx-mipi-csis.c b/drivers/media/platform/nxp/imx-mipi-csis.c
index b39d7aeba750..b08f6d2e7516 100644
--- a/drivers/media/platform/nxp/imx-mipi-csis.c
+++ b/drivers/media/platform/nxp/imx-mipi-csis.c
@@ -1435,24 +1435,18 @@ static int mipi_csis_probe(struct platform_device *pdev)
 	/* Reset PHY and enable the clocks. */
 	mipi_csis_phy_reset(csis);
 
-	ret = mipi_csis_clk_enable(csis);
-	if (ret < 0) {
-		dev_err(csis->dev, "failed to enable clocks: %d\n", ret);
-		return ret;
-	}
-
 	/* Now that the hardware is initialized, request the interrupt. */
 	ret = devm_request_irq(dev, irq, mipi_csis_irq_handler, 0,
 			       dev_name(dev), csis);
 	if (ret) {
 		dev_err(dev, "Interrupt request failed\n");
-		goto err_disable_clock;
+		return ret;
 	}
 
 	/* Initialize and register the subdev. */
 	ret = mipi_csis_subdev_init(csis);
 	if (ret < 0)
-		goto err_disable_clock;
+		return ret;
 
 	platform_set_drvdata(pdev, &csis->sd);
 
@@ -1486,8 +1480,6 @@ static int mipi_csis_probe(struct platform_device *pdev)
 	v4l2_async_nf_unregister(&csis->notifier);
 	v4l2_async_nf_cleanup(&csis->notifier);
 	v4l2_async_unregister_subdev(&csis->sd);
-err_disable_clock:
-	mipi_csis_clk_disable(csis);
 
 	return ret;
 }
@@ -1506,7 +1498,6 @@ static void mipi_csis_remove(struct platform_device *pdev)
 		mipi_csis_runtime_suspend(&pdev->dev);
 
 	pm_runtime_disable(&pdev->dev);
-	mipi_csis_clk_disable(csis);
 	v4l2_subdev_cleanup(&csis->sd);
 	media_entity_cleanup(&csis->sd.entity);
 	pm_runtime_set_suspended(&pdev->dev);

-- 
2.34.1