[PATCH] backlight: pwm_bl: Fix condition to set enable gpio as output

[PATCH] backlight: pwm_bl: Fix condition to set enable gpio as output

[Paul Kocialkowski]

The move to a dedicated pwm_backlight_initial_power_state function in
commit 7613c922315e308a6486d802abed2eb74443dffd modified the condition
to set the enable gpio as output. This breaks specific use cases using
that GPIO, such as tegra124-based nyan Chromebooks where backlight
stopped working.

This puts the condition back to the way it was before the move.

Signed-off-by: Paul Kocialkowski <contact@paulk.fr>
---
 drivers/video/backlight/pwm_bl.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/video/backlight/pwm_bl.c b/drivers/video/backlight/pwm_bl.c
index d7efcb632f7d..e81b2b55be2b 100644
--- a/drivers/video/backlight/pwm_bl.c
+++ b/drivers/video/backlight/pwm_bl.c
@@ -304,7 +304,8 @@ static int pwm_backlight_probe(struct platform_device *pdev)
 	 * early. Leave the decision of the initial backlight state for later.
 	 */
 	if (pb->enable_gpio &&
-	    gpiod_get_direction(pb->enable_gpio) == GPIOF_DIR_IN)
+	   (gpiod_get_direction(pb->enable_gpio) == GPIOF_DIR_IN ||
+	    gpiod_get_value(pb->enable_gpio) != 0))
 		gpiod_direction_output(pb->enable_gpio, 1);
 
 	pb->power_supply = devm_regulator_get(&pdev->dev, "power");
-- 
2.12.2

Re: [PATCH] backlight: pwm_bl: Fix condition to set enable gpio as output

[Geert Uytterhoeven]

Hi Paul,

On Sun, Apr 16, 2017 at 12:35 PM, Paul Kocialkowski <contact@paulk.fr> wrote:
> The move to a dedicated pwm_backlight_initial_power_state function in
> commit 7613c922315e308a6486d802abed2eb74443dffd modified the condition
> to set the enable gpio as output. This breaks specific use cases using
> that GPIO, such as tegra124-based nyan Chromebooks where backlight
> stopped working.
>
> This puts the condition back to the way it was before the move.
>
> Signed-off-by: Paul Kocialkowski <contact@paulk.fr>

Does "[PATCH v2] backlight: pwm_bl: Fix GPIO out for unimplemented
.get_direction()"
(https://lkml.org/lkml/2017/4/4/225) fix your issue?

Thanks!

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds

Re: [PATCH] backlight: pwm_bl: Fix condition to set enable gpio as output

[Paul Kocialkowski]

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Hi,

Le dimanche 16 avril 2017 à 22:55 +0200, Geert Uytterhoeven a écrit :
> On Sun, Apr 16, 2017 at 12:35 PM, Paul Kocialkowski <contact@paulk.fr> wrote:
> > The move to a dedicated pwm_backlight_initial_power_state function in
> > commit 7613c922315e308a6486d802abed2eb74443dffd modified the condition
> > to set the enable gpio as output. This breaks specific use cases using
> > that GPIO, such as tegra124-based nyan Chromebooks where backlight
> > stopped working.
> > 
> > This puts the condition back to the way it was before the move.
> > 
> > Signed-off-by: Paul Kocialkowski <contact@paulk.fr>
> 
> Does "[PATCH v2] backlight: pwm_bl: Fix GPIO out for unimplemented
> .get_direction()"
> (https://lkml.org/lkml/2017/4/4/225) fix your issue?

This definitely solves the issue!

Since this fixes broken backlight (that, in turn, makes systems unusable),
perhaps this should be included in the next rc cycle?

Cheers!

-- 
Paul Kocialkowski, developer of free digital technology at the lower levels

Website: https://www.paulk.fr/
Coding blog: https://code.paulk.fr/
Git repositories: https://git.paulk.fr/ https://git.code.paulk.fr/

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Re: [PATCH] backlight: pwm_bl: Fix condition to set enable gpio as output

[Geert Uytterhoeven]

Hi Paul,

On Mon, Apr 17, 2017 at 5:38 PM, Paul Kocialkowski <contact@paulk.fr> wrote:
> Le dimanche 16 avril 2017 à 22:55 +0200, Geert Uytterhoeven a écrit :
>> On Sun, Apr 16, 2017 at 12:35 PM, Paul Kocialkowski <contact@paulk.fr> wrote:
>> > The move to a dedicated pwm_backlight_initial_power_state function in
>> > commit 7613c922315e308a6486d802abed2eb74443dffd modified the condition
>> > to set the enable gpio as output. This breaks specific use cases using
>> > that GPIO, such as tegra124-based nyan Chromebooks where backlight
>> > stopped working.
>> >
>> > This puts the condition back to the way it was before the move.
>> >
>> > Signed-off-by: Paul Kocialkowski <contact@paulk.fr>
>>
>> Does "[PATCH v2] backlight: pwm_bl: Fix GPIO out for unimplemented
>> .get_direction()"
>> (https://lkml.org/lkml/2017/4/4/225) fix your issue?
>
> This definitely solves the issue!
>
> Since this fixes broken backlight (that, in turn, makes systems unusable),
> perhaps this should be included in the next rc cycle?

You mean v4.11 final, as there probably won't be another rc?
Yes!

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds

Re: [PATCH] backlight: pwm_bl: Fix condition to set enable gpio as output

[Paul Kocialkowski]

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Hi,

Le lundi 17 avril 2017 à 21:36 +0200, Geert Uytterhoeven a écrit :
> On Mon, Apr 17, 2017 at 5:38 PM, Paul Kocialkowski <contact@paulk.fr> wrote:
> > Le dimanche 16 avril 2017 à 22:55 +0200, Geert Uytterhoeven a écrit :
> > > On Sun, Apr 16, 2017 at 12:35 PM, Paul Kocialkowski <contact@paulk.fr>
> > > wrote:
> > > > The move to a dedicated pwm_backlight_initial_power_state function in
> > > > commit 7613c922315e308a6486d802abed2eb74443dffd modified the condition
> > > > to set the enable gpio as output. This breaks specific use cases using
> > > > that GPIO, such as tegra124-based nyan Chromebooks where backlight
> > > > stopped working.
> > > > 
> > > > This puts the condition back to the way it was before the move.
> > > > 
> > > > Signed-off-by: Paul Kocialkowski <contact@paulk.fr>
> > > 
> > > Does "[PATCH v2] backlight: pwm_bl: Fix GPIO out for unimplemented
> > > .get_direction()"
> > > (https://lkml.org/lkml/2017/4/4/225) fix your issue?
> > 
> > This definitely solves the issue!
> > 
> > Since this fixes broken backlight (that, in turn, makes systems unusable),
> > perhaps this should be included in the next rc cycle?
> 
> You mean v4.11 final, as there probably won't be another rc?
> Yes!

I'm all for it!

Cheers,

-- 
Paul Kocialkowski, developer of free digital technology at the lower levels

Website: https://www.paulk.fr/
Coding blog: https://code.paulk.fr/
Git repositories: https://git.paulk.fr/ https://git.code.paulk.fr/

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Re: [PATCH] backlight: pwm_bl: Fix condition to set enable gpio as output

[Daniel Thompson]

On 18/04/17 09:46, Paul Kocialkowski wrote:
> Hi,
>
> Le lundi 17 avril 2017 à 21:36 +0200, Geert Uytterhoeven a écrit :
>> On Mon, Apr 17, 2017 at 5:38 PM, Paul Kocialkowski <contact@paulk.fr> wrote:
>>> Le dimanche 16 avril 2017 à 22:55 +0200, Geert Uytterhoeven a écrit :
>>>> On Sun, Apr 16, 2017 at 12:35 PM, Paul Kocialkowski <contact@paulk.fr>
>>>> wrote:
>>>>> The move to a dedicated pwm_backlight_initial_power_state function in
>>>>> commit 7613c922315e308a6486d802abed2eb74443dffd modified the condition
>>>>> to set the enable gpio as output. This breaks specific use cases using
>>>>> that GPIO, such as tegra124-based nyan Chromebooks where backlight
>>>>> stopped working.
>>>>>
>>>>> This puts the condition back to the way it was before the move.
>>>>>
>>>>> Signed-off-by: Paul Kocialkowski <contact@paulk.fr>
>>>>
>>>> Does "[PATCH v2] backlight: pwm_bl: Fix GPIO out for unimplemented
>>>> .get_direction()"
>>>> (https://lkml.org/lkml/2017/4/4/225) fix your issue?
>>>
>>> This definitely solves the issue!
>>>
>>> Since this fixes broken backlight (that, in turn, makes systems unusable),
>>> perhaps this should be included in the next rc cycle?
>>
>> You mean v4.11 final, as there probably won't be another rc?
>> Yes!
>
> I'm all for it!

Thanks for keeping our attention on this. I sent a PR yesterday (and 
hope my GPG key has attracted enough signatures).


Daniel.

Re: [PATCH] backlight: pwm_bl: Fix condition to set enable gpio as output

[Geert Uytterhoeven]

Hi Daniel,

On Thu, Apr 20, 2017 at 11:55 AM, Daniel Thompson
<daniel.thompson@linaro.org> wrote:
> On 18/04/17 09:46, Paul Kocialkowski wrote:
>> Le lundi 17 avril 2017 à 21:36 +0200, Geert Uytterhoeven a écrit :
>>> On Mon, Apr 17, 2017 at 5:38 PM, Paul Kocialkowski <contact@paulk.fr>
>>> wrote:
>>>> Le dimanche 16 avril 2017 à 22:55 +0200, Geert Uytterhoeven a écrit :
>>>>> On Sun, Apr 16, 2017 at 12:35 PM, Paul Kocialkowski <contact@paulk.fr>
>>>>> wrote:
>>>>>>
>>>>>> The move to a dedicated pwm_backlight_initial_power_state function in
>>>>>> commit 7613c922315e308a6486d802abed2eb74443dffd modified the condition
>>>>>> to set the enable gpio as output. This breaks specific use cases using
>>>>>> that GPIO, such as tegra124-based nyan Chromebooks where backlight
>>>>>> stopped working.
>>>>>>
>>>>>> This puts the condition back to the way it was before the move.
>>>>>>
>>>>>> Signed-off-by: Paul Kocialkowski <contact@paulk.fr>
>>>>>
>>>>> Does "[PATCH v2] backlight: pwm_bl: Fix GPIO out for unimplemented
>>>>> .get_direction()"
>>>>> (https://lkml.org/lkml/2017/4/4/225) fix your issue?
>>>>
>>>> This definitely solves the issue!
>>>>
>>>> Since this fixes broken backlight (that, in turn, makes systems
>>>> unusable),
>>>> perhaps this should be included in the next rc cycle?
>>>
>>> You mean v4.11 final, as there probably won't be another rc?
>>> Yes!
>>
>> I'm all for it!
>
> Thanks for keeping our attention on this. I sent a PR yesterday (and hope my
> GPG key has attracted enough signatures).

Thank you, this morning I had already noticed it went upstream.

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds

Re: [PATCH] backlight: pwm_bl: Fix condition to set enable gpio as output

[Paul Kocialkowski]

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Hi,

Le jeudi 20 avril 2017 à 10:55 +0100, Daniel Thompson a écrit :
> On 18/04/17 09:46, Paul Kocialkowski wrote:
> > Hi,
> > 
> > Le lundi 17 avril 2017 à 21:36 +0200, Geert Uytterhoeven a écrit :
> > > On Mon, Apr 17, 2017 at 5:38 PM, Paul Kocialkowski <contact@paulk.fr>
> > > wrote:
> > > > Le dimanche 16 avril 2017 à 22:55 +0200, Geert Uytterhoeven a écrit :
> > > > > On Sun, Apr 16, 2017 at 12:35 PM, Paul Kocialkowski <contact@paulk.fr>
> > > > > wrote:
> > > > > > The move to a dedicated pwm_backlight_initial_power_state function
> > > > > > in
> > > > > > commit 7613c922315e308a6486d802abed2eb74443dffd modified the
> > > > > > condition
> > > > > > to set the enable gpio as output. This breaks specific use cases
> > > > > > using
> > > > > > that GPIO, such as tegra124-based nyan Chromebooks where backlight
> > > > > > stopped working.
> > > > > > 
> > > > > > This puts the condition back to the way it was before the move.
> > > > > > 
> > > > > > Signed-off-by: Paul Kocialkowski <contact@paulk.fr>
> > > > > 
> > > > > Does "[PATCH v2] backlight: pwm_bl: Fix GPIO out for unimplemented
> > > > > .get_direction()"
> > > > > (https://lkml.org/lkml/2017/4/4/225) fix your issue?
> > > > 
> > > > This definitely solves the issue!
> > > > 
> > > > Since this fixes broken backlight (that, in turn, makes systems
> > > > unusable),
> > > > perhaps this should be included in the next rc cycle?
> > > 
> > > You mean v4.11 final, as there probably won't be another rc?
> > > Yes!
> > 
> > I'm all for it!
> 
> Thanks for keeping our attention on this. I sent a PR yesterday (and 
> hope my GPG key has attracted enough signatures).

Thanks for acting fast and getting this merged already. This is greatly
appreciated!

Cheers,

-- 
Paul Kocialkowski, developer of free digital technology at the lower levels

Website: https://www.paulk.fr/
Coding blog: https://code.paulk.fr/
Git repositories: https://git.paulk.fr/ https://git.code.paulk.fr/

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