linux-kernel - [PATCH v4] drm: mediatek: Modify dpi power on/off sequence.

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Message-ID: <1667988059-8635-1-git-send-email-xinlei.lee@mediatek.com>
Date:   Wed, 9 Nov 2022 18:00:59 +0800
From:   <xinlei.lee@...iatek.com>
To:     <chunkuang.hu@...nel.org>, <p.zabel@...gutronix.de>,
        <airlied@...ux.ie>, <daniel@...ll.ch>, <matthias.bgg@...il.com>,
        <jitao.shi@...iatek.com>
CC:     <dri-devel@...ts.freedesktop.org>,
        <linux-mediatek@...ts.infradead.org>,
        <linux-arm-kernel@...ts.infradead.org>,
        <linux-kernel@...r.kernel.org>,
        <Project_Global_Chrome_Upstream_Group@...iatek.com>,
        Xinlei Lee <xinlei.lee@...iatek.com>
Subject: [PATCH v4] drm: mediatek: Modify dpi power on/off sequence.

From: Xinlei Lee <xinlei.lee@...iatek.com>

Modify dpi power on/off sequence so that the first gpio operation will take effect.

Fixes: 6bd4763fd532 ("drm/mediatek: set dpi pin mode to gpio low to avoid leakage current")
Signed-off-by: Xinlei Lee <xinlei.lee@...iatek.com>
---
change note:
v3: Moved pull-down pin control after mtk_dpi_power_off.

v2: Remove the empty line between Fixes: and S-o-b.

v1: Rebase on linus/master v6.1-rc1. Change nothing.

Because dpi power_on/off is protected by dpi->refcount, the first time
it cannot be powered on and off successfully, it will cause leakage.
---
---
 drivers/gpu/drm/mediatek/mtk_dpi.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/mediatek/mtk_dpi.c b/drivers/gpu/drm/mediatek/mtk_dpi.c
index 508a6d994e83..1f5d39a4077c 100644
--- a/drivers/gpu/drm/mediatek/mtk_dpi.c
+++ b/drivers/gpu/drm/mediatek/mtk_dpi.c
@@ -461,9 +461,6 @@ static void mtk_dpi_power_off(struct mtk_dpi *dpi)
 	if (--dpi->refcount != 0)
 		return;
 
-	if (dpi->pinctrl && dpi->pins_gpio)
-		pinctrl_select_state(dpi->pinctrl, dpi->pins_gpio);
-
 	mtk_dpi_disable(dpi);
 	clk_disable_unprepare(dpi->pixel_clk);
 	clk_disable_unprepare(dpi->engine_clk);
@@ -488,9 +485,6 @@ static int mtk_dpi_power_on(struct mtk_dpi *dpi)
 		goto err_pixel;
 	}
 
-	if (dpi->pinctrl && dpi->pins_dpi)
-		pinctrl_select_state(dpi->pinctrl, dpi->pins_dpi);
-
 	return 0;
 
 err_pixel:
@@ -721,12 +715,18 @@ static void mtk_dpi_bridge_disable(struct drm_bridge *bridge)
 	struct mtk_dpi *dpi = bridge_to_dpi(bridge);
 
 	mtk_dpi_power_off(dpi);
+
+	if (dpi->pinctrl && dpi->pins_gpio)
+		pinctrl_select_state(dpi->pinctrl, dpi->pins_gpio);
 }
 
 static void mtk_dpi_bridge_enable(struct drm_bridge *bridge)
 {
 	struct mtk_dpi *dpi = bridge_to_dpi(bridge);
 
+	if (dpi->pinctrl && dpi->pins_dpi)
+		pinctrl_select_state(dpi->pinctrl, dpi->pins_dpi);
+
 	mtk_dpi_power_on(dpi);
 	mtk_dpi_set_display_mode(dpi, &dpi->mode);
 	mtk_dpi_enable(dpi);
-- 
2.18.0