2022-09-05 14:08:01

by Xinlei Lee (李昕磊)

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

From: Xinlei Lee <[email protected]>

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 <[email protected]>

---
Base on the branch of Linux-next/master.
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 630a4e301ef6..2ce1a39ce3bf 100644
--- a/drivers/gpu/drm/mediatek/mtk_dpi.c
+++ b/drivers/gpu/drm/mediatek/mtk_dpi.c
@@ -462,9 +462,6 @@ 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);
@@ -489,9 +486,6 @@ 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:
@@ -721,6 +715,9 @@ static void mtk_dpi_bridge_disable(struct drm_bridge *bridge)
{
struct mtk_dpi *dpi = bridge_to_dpi(bridge);

+ if (dpi->pinctrl && dpi->pins_gpio)
+ pinctrl_select_state(dpi->pinctrl, dpi->pins_gpio);
+
mtk_dpi_power_off(dpi);
}

@@ -728,6 +725,9 @@ 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

2022-11-08 08:08:45

by CK Hu (胡俊光)

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

Hi, Xinlei:

On Wed, 2022-10-12 at 15:48 +0800, xinlei.lee wrote:
> On Mon, 2022-09-05 at 21:53 +0800, [email protected] wrote:
> > From: Xinlei Lee <[email protected]>
> >
> > 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 <[email protected]>
> >
> > ---
> > Base on the branch of Linux-next/master.
> > 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 630a4e301ef6..2ce1a39ce3bf 100644
> > --- a/drivers/gpu/drm/mediatek/mtk_dpi.c
> > +++ b/drivers/gpu/drm/mediatek/mtk_dpi.c
> > @@ -462,9 +462,6 @@ 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);
> > @@ -489,9 +486,6 @@ 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:
> > @@ -721,6 +715,9 @@ static void mtk_dpi_bridge_disable(struct
> > drm_bridge *bridge)
> > {
> > struct mtk_dpi *dpi = bridge_to_dpi(bridge);
> >
> > + if (dpi->pinctrl && dpi->pins_gpio)
> > + pinctrl_select_state(dpi->pinctrl, dpi->pins_gpio);

I think this should be placed after mtk_dpi_power_off().

> > +
> > mtk_dpi_power_off(dpi);
> > }
> >
> > @@ -728,6 +725,9 @@ 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);
>
> Hi CK,
>
> Gentle ping for this patch, if there is anything I need to modify,
> please kindly let me know.
>
> Best Regards!
> xinlei
>

2022-11-09 02:45:10

by Xinlei Lee (李昕磊)

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

On Tue, 2022-11-08 at 07:44 +0000, CK Hu (胡俊光) wrote:
> Hi, Xinlei:
>
> On Wed, 2022-10-12 at 15:48 +0800, xinlei.lee wrote:
> > On Mon, 2022-09-05 at 21:53 +0800, [email protected] wrote:
> > > From: Xinlei Lee <[email protected]>
> > >
> > > 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 <[email protected]>
> > >
> > > ---
> > > Base on the branch of Linux-next/master.
> > > 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 630a4e301ef6..2ce1a39ce3bf 100644
> > > --- a/drivers/gpu/drm/mediatek/mtk_dpi.c
> > > +++ b/drivers/gpu/drm/mediatek/mtk_dpi.c
> > > @@ -462,9 +462,6 @@ 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);
> > > @@ -489,9 +486,6 @@ 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:
> > > @@ -721,6 +715,9 @@ static void mtk_dpi_bridge_disable(struct
> > > drm_bridge *bridge)
> > > {
> > > struct mtk_dpi *dpi = bridge_to_dpi(bridge);
> > >
> > > + if (dpi->pinctrl && dpi->pins_gpio)
> > > + pinctrl_select_state(dpi->pinctrl, dpi->pins_gpio);
>
> I think this should be placed after mtk_dpi_power_off().
>
> > > +
> > > mtk_dpi_power_off(dpi);
> > > }
> > >
> > > @@ -728,6 +725,9 @@ 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);
> >
> > Hi CK,
> >
> > Gentle ping for this patch, if there is anything I need to modify,
> > please kindly let me know.
> >
> > Best Regards!
> > xinlei
> >

Hi CK:

Yes, this pacth is mainly to remove the control of the pin from
dpi_power_on/off, because dpi_power_on/off is protected by refcount.

I will modify the position of the pull-down gpio in the next version.

Best Regards!
xinlei