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From:   Douglas Anderson <dianders@chromium.org>
To:     dri-devel@lists.freedesktop.org, Maxime Ripard <mripard@kernel.org>
Cc:     Douglas Anderson <dianders@chromium.org>,
        Sascha Hauer <s.hauer@pengutronix.de>, airlied@gmail.com,
        daniel@ffwll.ch, festevam@gmail.com, kernel@pengutronix.de,
        l.stach@pengutronix.de, laurentiu.palcu@oss.nxp.com,
        linux-arm-kernel@lists.infradead.org, linux-imx@nxp.com,
        linux-kernel@vger.kernel.org, shawnguo@kernel.org
Subject: [RFT PATCH v2 01/12] drm/imx/dcss: Call drm_atomic_helper_shutdown() at shutdown time
Date:   Thu, 21 Sep 2023 12:26:44 -0700
Message-ID: <20230921122641.RFT.v2.1.I134336fce7eac5a63bdac46d57b0888858fc8081@changeid>
In-Reply-To: <20230921192749.1542462-1-dianders@chromium.org>
References: <20230921192749.1542462-1-dianders@chromium.org>
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Based on grepping through the source code this driver appears to be
missing a call to drm_atomic_helper_shutdown() at system shutdown
time. Among other things, this means that if a panel is in use that it
won't be cleanly powered off at system shutdown time.

The fact that we should call drm_atomic_helper_shutdown() in the case
of OS shutdown/restart comes straight out of the kernel doc "driver
instance overview" in drm_drv.c.

Suggested-by: Maxime Ripard <mripard@kernel.org>
Reviewed-by: Maxime Ripard <mripard@kernel.org>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
---
This commit is only compile-time tested.

(no changes since v1)

 drivers/gpu/drm/imx/dcss/dcss-drv.c | 8 ++++++++
 drivers/gpu/drm/imx/dcss/dcss-kms.c | 7 +++++++
 drivers/gpu/drm/imx/dcss/dcss-kms.h | 1 +
 3 files changed, 16 insertions(+)

diff --git a/drivers/gpu/drm/imx/dcss/dcss-drv.c b/drivers/gpu/drm/imx/dcss/dcss-drv.c
index c68b0d93ae9e..b61cec0cc79d 100644
--- a/drivers/gpu/drm/imx/dcss/dcss-drv.c
+++ b/drivers/gpu/drm/imx/dcss/dcss-drv.c
@@ -92,6 +92,13 @@ static int dcss_drv_platform_remove(struct platform_device *pdev)
 	return 0;
 }
 
+static void dcss_drv_platform_shutdown(struct platform_device *pdev)
+{
+	struct dcss_drv *mdrv = dev_get_drvdata(&pdev->dev);
+
+	dcss_kms_shutdown(mdrv->kms);
+}
+
 static struct dcss_type_data dcss_types[] = {
 	[DCSS_IMX8MQ] = {
 		.name = "DCSS_IMX8MQ",
@@ -114,6 +121,7 @@ MODULE_DEVICE_TABLE(of, dcss_of_match);
 static struct platform_driver dcss_platform_driver = {
 	.probe	= dcss_drv_platform_probe,
 	.remove	= dcss_drv_platform_remove,
+	.shutdown = dcss_drv_platform_shutdown,
 	.driver	= {
 		.name = "imx-dcss",
 		.of_match_table	= dcss_of_match,
diff --git a/drivers/gpu/drm/imx/dcss/dcss-kms.c b/drivers/gpu/drm/imx/dcss/dcss-kms.c
index 896de946f8df..d0ea4e97cded 100644
--- a/drivers/gpu/drm/imx/dcss/dcss-kms.c
+++ b/drivers/gpu/drm/imx/dcss/dcss-kms.c
@@ -172,3 +172,10 @@ void dcss_kms_detach(struct dcss_kms_dev *kms)
 	dcss_crtc_deinit(&kms->crtc, drm);
 	drm->dev_private = NULL;
 }
+
+void dcss_kms_shutdown(struct dcss_kms_dev *kms)
+{
+	struct drm_device *drm = &kms->base;
+
+	drm_atomic_helper_shutdown(drm);
+}
diff --git a/drivers/gpu/drm/imx/dcss/dcss-kms.h b/drivers/gpu/drm/imx/dcss/dcss-kms.h
index dfe5dd99eea3..62521c1fd6d2 100644
--- a/drivers/gpu/drm/imx/dcss/dcss-kms.h
+++ b/drivers/gpu/drm/imx/dcss/dcss-kms.h
@@ -34,6 +34,7 @@ struct dcss_kms_dev {
 
 struct dcss_kms_dev *dcss_kms_attach(struct dcss_dev *dcss);
 void dcss_kms_detach(struct dcss_kms_dev *kms);
+void dcss_kms_shutdown(struct dcss_kms_dev *kms);
 int dcss_crtc_init(struct dcss_crtc *crtc, struct drm_device *drm);
 void dcss_crtc_deinit(struct dcss_crtc *crtc, struct drm_device *drm);
 struct dcss_plane *dcss_plane_init(struct drm_device *drm,
-- 
2.42.0.515.g380fc7ccd1-goog