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

From: xinlei.lee
Date: Wed Nov 09 2022 - 05:01:20 EST


From: Xinlei Lee <xinlei.lee@xxxxxxxxxxxx>

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@xxxxxxxxxxxx>
---
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