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From:   Hsin-Yi Wang <hsinyi@chromium.org>
To:     Chun-Kuang Hu <chunkuang.hu@kernel.org>
Cc:     Philipp Zabel <p.zabel@pengutronix.de>,
        David Airlie <airlied@linux.ie>,
        Daniel Vetter <daniel@ffwll.ch>,
        Matthias Brugger <matthias.bgg@gmail.com>,
        dri-devel@lists.freedesktop.org,
        linux-mediatek@lists.infradead.org,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org
Subject: [PATCH] drm/mediatek: ensure bridge disable happends before suspend
Date:   Thu, 30 Jun 2022 03:05:46 +0800
Message-Id: <20220629190545.478113-1-hsinyi@chromium.org>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

Make sure bridge_disable will be called before suspend by calling
drm_mode_config_helper_suspend() in .prepare callback.

Signed-off-by: Hsin-Yi Wang <hsinyi@chromium.org>
---
The issue is found if suspend is called via VT2 in several MTK SoC (eg.
MT8173, MT8183, MT8186) chromebook boards with eDP bridge:
bridge disable is called through mtk-drm's suspend, and it needs to be
called before bridge pm runtime suspend.
So we move the hook to .prepare() and .complete().
---
 drivers/gpu/drm/mediatek/mtk_drm_drv.c | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/drivers/gpu/drm/mediatek/mtk_drm_drv.c b/drivers/gpu/drm/mediatek/mtk_drm_drv.c
index 13a1bbe7ead7f..a42812e490007 100644
--- a/drivers/gpu/drm/mediatek/mtk_drm_drv.c
+++ b/drivers/gpu/drm/mediatek/mtk_drm_drv.c
@@ -828,8 +828,7 @@ static int mtk_drm_remove(struct platform_device *pdev)
 	return 0;
 }
 
-#ifdef CONFIG_PM_SLEEP
-static int mtk_drm_sys_suspend(struct device *dev)
+static int mtk_drm_sys_prepare(struct device *dev)
 {
 	struct mtk_drm_private *private = dev_get_drvdata(dev);
 	struct drm_device *drm = private->drm;
@@ -840,20 +839,21 @@ static int mtk_drm_sys_suspend(struct device *dev)
 	return ret;
 }
 
-static int mtk_drm_sys_resume(struct device *dev)
+static void mtk_drm_sys_complete(struct device *dev)
 {
 	struct mtk_drm_private *private = dev_get_drvdata(dev);
 	struct drm_device *drm = private->drm;
 	int ret;
 
 	ret = drm_mode_config_helper_resume(drm);
-
-	return ret;
+	if (ret)
+		dev_err(dev, "Failed to resume\n");
 }
-#endif
 
-static SIMPLE_DEV_PM_OPS(mtk_drm_pm_ops, mtk_drm_sys_suspend,
-			 mtk_drm_sys_resume);
+static const struct dev_pm_ops mtk_drm_pm_ops = {
+	.prepare = mtk_drm_sys_prepare,
+	.complete = mtk_drm_sys_complete,
+};
 
 static struct platform_driver mtk_drm_platform_driver = {
 	.probe	= mtk_drm_probe,
-- 
2.37.0.rc0.161.g10f37bed90-goog