Re: [PATCH] backlight: pwm_bl: Fix GPIO out for unimplemented .get_direction()
On Fri, 24 Mar 2017, Daniel Thompson wrote:
> On 24/03/17 16:42, Daniel Thompson wrote:
> > On 22/03/17 17:21, Geert Uytterhoeven wrote:
> > > Commit 7613c922315e308a ("backlight: pwm_bl: Move the checks for initial
> > > power state to a separate function") not just moved some code, but made
> > > slight changes in semantics.
> > >
> > > If a gpiochip doesn't implement the optional .get_direction() callback,
> > > gpiod_get_direction always returns -EINVAL, which is never equal to
> > > GPIOF_DIR_IN, leading to the GPIO not being configured for output.
> > >
> > > To avoid this, invert the test and check for not GPIOF_DIR_OUT instead,
> > > like the original code did.
> > >
> > > This restores the display on r8a7740/armadillo.
> > >
> > > Fixes: 7613c922315e308a ("backlight: pwm_bl: Move the checks for
> > > initial power state to a separate function")
> > > Signed-off-by: Geert Uytterhoeven
> >
> > Acked-by: Daniel Thommpson
>
> Actually, it would be better if there only one m...
>
> Acked-by: Daniel Thompson
You probably don't want to be typing out your Acks manually every
time. Can you set a key combination in your editor?
> > > ---
> > > drivers/video/backlight/pwm_bl.c | 7 ---
> > > 1 file changed, 4 insertions(+), 3 deletions(-)
> > >
> > > diff --git a/drivers/video/backlight/pwm_bl.c
> > > b/drivers/video/backlight/pwm_bl.c
> > > index d7efcb632f7d9dde..002f1ce22bd02032 100644
> > > --- a/drivers/video/backlight/pwm_bl.c
> > > +++ b/drivers/video/backlight/pwm_bl.c
> > > @@ -297,14 +297,15 @@ static int pwm_backlight_probe(struct
> > > platform_device *pdev)
> > > }
> > >
> > > /*
> > > - * If the GPIO is configured as input, change the direction to
> > > output
> > > - * and set the GPIO as active.
> > > + * If the GPIO is not known to be already configured as output, that
> > > + * is, if gpiod_get_direction returns either GPIOF_DIR_IN or
> > > -EINVAL,
> > > + * change the direction to output and set the GPIO as active.
> > > * Do not force the GPIO to active when it was already output as it
> > > * could cause backlight flickering or we would enable the
> > > backlight too
> > > * 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_OUT)
> > > gpiod_direction_output(pb->enable_gpio, 1);
> > >
> > > pb->power_supply = devm_regulator_get(>dev, "power");
> > >
> >
>
--
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org │ Open source software for ARM SoCs
Follow Linaro: Facebook | Twitter | Blog
Re: [PATCH] backlight: pwm_bl: Fix GPIO out for unimplemented .get_direction()
On Fri, 24 Mar 2017, Daniel Thompson wrote:
> On 24/03/17 16:42, Daniel Thompson wrote:
> > On 22/03/17 17:21, Geert Uytterhoeven wrote:
> > > Commit 7613c922315e308a ("backlight: pwm_bl: Move the checks for initial
> > > power state to a separate function") not just moved some code, but made
> > > slight changes in semantics.
> > >
> > > If a gpiochip doesn't implement the optional .get_direction() callback,
> > > gpiod_get_direction always returns -EINVAL, which is never equal to
> > > GPIOF_DIR_IN, leading to the GPIO not being configured for output.
> > >
> > > To avoid this, invert the test and check for not GPIOF_DIR_OUT instead,
> > > like the original code did.
> > >
> > > This restores the display on r8a7740/armadillo.
> > >
> > > Fixes: 7613c922315e308a ("backlight: pwm_bl: Move the checks for
> > > initial power state to a separate function")
> > > Signed-off-by: Geert Uytterhoeven
> >
> > Acked-by: Daniel Thommpson
>
> Actually, it would be better if there only one m...
>
> Acked-by: Daniel Thompson
You probably don't want to be typing out your Acks manually every
time. Can you set a key combination in your editor?
> > > ---
> > > drivers/video/backlight/pwm_bl.c | 7 ---
> > > 1 file changed, 4 insertions(+), 3 deletions(-)
> > >
> > > diff --git a/drivers/video/backlight/pwm_bl.c
> > > b/drivers/video/backlight/pwm_bl.c
> > > index d7efcb632f7d9dde..002f1ce22bd02032 100644
> > > --- a/drivers/video/backlight/pwm_bl.c
> > > +++ b/drivers/video/backlight/pwm_bl.c
> > > @@ -297,14 +297,15 @@ static int pwm_backlight_probe(struct
> > > platform_device *pdev)
> > > }
> > >
> > > /*
> > > - * If the GPIO is configured as input, change the direction to
> > > output
> > > - * and set the GPIO as active.
> > > + * If the GPIO is not known to be already configured as output, that
> > > + * is, if gpiod_get_direction returns either GPIOF_DIR_IN or
> > > -EINVAL,
> > > + * change the direction to output and set the GPIO as active.
> > > * Do not force the GPIO to active when it was already output as it
> > > * could cause backlight flickering or we would enable the
> > > backlight too
> > > * 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_OUT)
> > > gpiod_direction_output(pb->enable_gpio, 1);
> > >
> > > pb->power_supply = devm_regulator_get(>dev, "power");
> > >
> >
>
--
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org │ Open source software for ARM SoCs
Follow Linaro: Facebook | Twitter | Blog
Re: [PATCH] backlight: pwm_bl: Fix GPIO out for unimplemented .get_direction()
On 24/03/17 16:42, Daniel Thompson wrote:
On 22/03/17 17:21, Geert Uytterhoeven wrote:
Commit 7613c922315e308a ("backlight: pwm_bl: Move the checks for initial
power state to a separate function") not just moved some code, but made
slight changes in semantics.
If a gpiochip doesn't implement the optional .get_direction() callback,
gpiod_get_direction always returns -EINVAL, which is never equal to
GPIOF_DIR_IN, leading to the GPIO not being configured for output.
To avoid this, invert the test and check for not GPIOF_DIR_OUT instead,
like the original code did.
This restores the display on r8a7740/armadillo.
Fixes: 7613c922315e308a ("backlight: pwm_bl: Move the checks for
initial power state to a separate function")
Signed-off-by: Geert Uytterhoeven
Acked-by: Daniel Thommpson
Actually, it would be better if there only one m...
Acked-by: Daniel Thompson
Daniel.
---
drivers/video/backlight/pwm_bl.c | 7 ---
1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/drivers/video/backlight/pwm_bl.c
b/drivers/video/backlight/pwm_bl.c
index d7efcb632f7d9dde..002f1ce22bd02032 100644
--- a/drivers/video/backlight/pwm_bl.c
+++ b/drivers/video/backlight/pwm_bl.c
@@ -297,14 +297,15 @@ static int pwm_backlight_probe(struct
platform_device *pdev)
}
/*
- * If the GPIO is configured as input, change the direction to
output
- * and set the GPIO as active.
+ * If the GPIO is not known to be already configured as output, that
+ * is, if gpiod_get_direction returns either GPIOF_DIR_IN or
-EINVAL,
+ * change the direction to output and set the GPIO as active.
* Do not force the GPIO to active when it was already output as it
* could cause backlight flickering or we would enable the
backlight too
* 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_OUT)
gpiod_direction_output(pb->enable_gpio, 1);
pb->power_supply = devm_regulator_get(>dev, "power");
Re: [PATCH] backlight: pwm_bl: Fix GPIO out for unimplemented .get_direction()
On 24/03/17 16:42, Daniel Thompson wrote:
On 22/03/17 17:21, Geert Uytterhoeven wrote:
Commit 7613c922315e308a ("backlight: pwm_bl: Move the checks for initial
power state to a separate function") not just moved some code, but made
slight changes in semantics.
If a gpiochip doesn't implement the optional .get_direction() callback,
gpiod_get_direction always returns -EINVAL, which is never equal to
GPIOF_DIR_IN, leading to the GPIO not being configured for output.
To avoid this, invert the test and check for not GPIOF_DIR_OUT instead,
like the original code did.
This restores the display on r8a7740/armadillo.
Fixes: 7613c922315e308a ("backlight: pwm_bl: Move the checks for
initial power state to a separate function")
Signed-off-by: Geert Uytterhoeven
Acked-by: Daniel Thommpson
Actually, it would be better if there only one m...
Acked-by: Daniel Thompson
Daniel.
---
drivers/video/backlight/pwm_bl.c | 7 ---
1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/drivers/video/backlight/pwm_bl.c
b/drivers/video/backlight/pwm_bl.c
index d7efcb632f7d9dde..002f1ce22bd02032 100644
--- a/drivers/video/backlight/pwm_bl.c
+++ b/drivers/video/backlight/pwm_bl.c
@@ -297,14 +297,15 @@ static int pwm_backlight_probe(struct
platform_device *pdev)
}
/*
- * If the GPIO is configured as input, change the direction to
output
- * and set the GPIO as active.
+ * If the GPIO is not known to be already configured as output, that
+ * is, if gpiod_get_direction returns either GPIOF_DIR_IN or
-EINVAL,
+ * change the direction to output and set the GPIO as active.
* Do not force the GPIO to active when it was already output as it
* could cause backlight flickering or we would enable the
backlight too
* 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_OUT)
gpiod_direction_output(pb->enable_gpio, 1);
pb->power_supply = devm_regulator_get(>dev, "power");
Re: [PATCH] backlight: pwm_bl: Fix GPIO out for unimplemented .get_direction()
On 22/03/17 17:21, Geert Uytterhoeven wrote:
Commit 7613c922315e308a ("backlight: pwm_bl: Move the checks for initial
power state to a separate function") not just moved some code, but made
slight changes in semantics.
If a gpiochip doesn't implement the optional .get_direction() callback,
gpiod_get_direction always returns -EINVAL, which is never equal to
GPIOF_DIR_IN, leading to the GPIO not being configured for output.
To avoid this, invert the test and check for not GPIOF_DIR_OUT instead,
like the original code did.
This restores the display on r8a7740/armadillo.
Fixes: 7613c922315e308a ("backlight: pwm_bl: Move the checks for initial power state
to a separate function")
Signed-off-by: Geert Uytterhoeven
Acked-by: Daniel Thommpson
---
drivers/video/backlight/pwm_bl.c | 7 ---
1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/drivers/video/backlight/pwm_bl.c b/drivers/video/backlight/pwm_bl.c
index d7efcb632f7d9dde..002f1ce22bd02032 100644
--- a/drivers/video/backlight/pwm_bl.c
+++ b/drivers/video/backlight/pwm_bl.c
@@ -297,14 +297,15 @@ static int pwm_backlight_probe(struct platform_device
*pdev)
}
/*
-* If the GPIO is configured as input, change the direction to output
-* and set the GPIO as active.
+* If the GPIO is not known to be already configured as output, that
+* is, if gpiod_get_direction returns either GPIOF_DIR_IN or -EINVAL,
+* change the direction to output and set the GPIO as active.
* Do not force the GPIO to active when it was already output as it
* could cause backlight flickering or we would enable the backlight too
* 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_OUT)
gpiod_direction_output(pb->enable_gpio, 1);
pb->power_supply = devm_regulator_get(>dev, "power");
Re: [PATCH] backlight: pwm_bl: Fix GPIO out for unimplemented .get_direction()
On 22/03/17 17:21, Geert Uytterhoeven wrote:
Commit 7613c922315e308a ("backlight: pwm_bl: Move the checks for initial
power state to a separate function") not just moved some code, but made
slight changes in semantics.
If a gpiochip doesn't implement the optional .get_direction() callback,
gpiod_get_direction always returns -EINVAL, which is never equal to
GPIOF_DIR_IN, leading to the GPIO not being configured for output.
To avoid this, invert the test and check for not GPIOF_DIR_OUT instead,
like the original code did.
This restores the display on r8a7740/armadillo.
Fixes: 7613c922315e308a ("backlight: pwm_bl: Move the checks for initial power state
to a separate function")
Signed-off-by: Geert Uytterhoeven
Acked-by: Daniel Thommpson
---
drivers/video/backlight/pwm_bl.c | 7 ---
1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/drivers/video/backlight/pwm_bl.c b/drivers/video/backlight/pwm_bl.c
index d7efcb632f7d9dde..002f1ce22bd02032 100644
--- a/drivers/video/backlight/pwm_bl.c
+++ b/drivers/video/backlight/pwm_bl.c
@@ -297,14 +297,15 @@ static int pwm_backlight_probe(struct platform_device
*pdev)
}
/*
-* If the GPIO is configured as input, change the direction to output
-* and set the GPIO as active.
+* If the GPIO is not known to be already configured as output, that
+* is, if gpiod_get_direction returns either GPIOF_DIR_IN or -EINVAL,
+* change the direction to output and set the GPIO as active.
* Do not force the GPIO to active when it was already output as it
* could cause backlight flickering or we would enable the backlight too
* 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_OUT)
gpiod_direction_output(pb->enable_gpio, 1);
pb->power_supply = devm_regulator_get(>dev, "power");
Re: [PATCH] backlight: pwm_bl: Fix GPIO out for unimplemented .get_direction()
On Wed, 2017-03-22 at 18:21 +0100, Geert Uytterhoeven wrote:
> Commit 7613c922315e308a ("backlight: pwm_bl: Move the checks for initial
> power state to a separate function") not just moved some code, but made
> slight changes in semantics.
>
> If a gpiochip doesn't implement the optional .get_direction() callback,
> gpiod_get_direction always returns -EINVAL, which is never equal to
> GPIOF_DIR_IN, leading to the GPIO not being configured for output.
>
> To avoid this, invert the test and check for not GPIOF_DIR_OUT instead,
> like the original code did.
>
> This restores the display on r8a7740/armadillo.
>
> Fixes: 7613c922315e308a ("backlight: pwm_bl: Move the checks for initial
> power state to a separate function")
> Signed-off-by: Geert Uytterhoeven
Acked-by: Philipp Zabel
regards
Philipp
> ---
> drivers/video/backlight/pwm_bl.c | 7 ---
> 1 file changed, 4 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/video/backlight/pwm_bl.c
> b/drivers/video/backlight/pwm_bl.c
> index d7efcb632f7d9dde..002f1ce22bd02032 100644
> --- a/drivers/video/backlight/pwm_bl.c
> +++ b/drivers/video/backlight/pwm_bl.c
> @@ -297,14 +297,15 @@ static int pwm_backlight_probe(struct platform_device
> *pdev)
> }
>
> /*
> - * If the GPIO is configured as input, change the direction to output
> - * and set the GPIO as active.
> + * If the GPIO is not known to be already configured as output, that
> + * is, if gpiod_get_direction returns either GPIOF_DIR_IN or -EINVAL,
> + * change the direction to output and set the GPIO as active.
>* Do not force the GPIO to active when it was already output as it
>* could cause backlight flickering or we would enable the backlight too
>* 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_OUT)
> gpiod_direction_output(pb->enable_gpio, 1);
>
> pb->power_supply = devm_regulator_get(>dev, "power");
Re: [PATCH] backlight: pwm_bl: Fix GPIO out for unimplemented .get_direction()
On Wed, 2017-03-22 at 18:21 +0100, Geert Uytterhoeven wrote:
> Commit 7613c922315e308a ("backlight: pwm_bl: Move the checks for initial
> power state to a separate function") not just moved some code, but made
> slight changes in semantics.
>
> If a gpiochip doesn't implement the optional .get_direction() callback,
> gpiod_get_direction always returns -EINVAL, which is never equal to
> GPIOF_DIR_IN, leading to the GPIO not being configured for output.
>
> To avoid this, invert the test and check for not GPIOF_DIR_OUT instead,
> like the original code did.
>
> This restores the display on r8a7740/armadillo.
>
> Fixes: 7613c922315e308a ("backlight: pwm_bl: Move the checks for initial
> power state to a separate function")
> Signed-off-by: Geert Uytterhoeven
Acked-by: Philipp Zabel
regards
Philipp
> ---
> drivers/video/backlight/pwm_bl.c | 7 ---
> 1 file changed, 4 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/video/backlight/pwm_bl.c
> b/drivers/video/backlight/pwm_bl.c
> index d7efcb632f7d9dde..002f1ce22bd02032 100644
> --- a/drivers/video/backlight/pwm_bl.c
> +++ b/drivers/video/backlight/pwm_bl.c
> @@ -297,14 +297,15 @@ static int pwm_backlight_probe(struct platform_device
> *pdev)
> }
>
> /*
> - * If the GPIO is configured as input, change the direction to output
> - * and set the GPIO as active.
> + * If the GPIO is not known to be already configured as output, that
> + * is, if gpiod_get_direction returns either GPIOF_DIR_IN or -EINVAL,
> + * change the direction to output and set the GPIO as active.
>* Do not force the GPIO to active when it was already output as it
>* could cause backlight flickering or we would enable the backlight too
>* 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_OUT)
> gpiod_direction_output(pb->enable_gpio, 1);
>
> pb->power_supply = devm_regulator_get(>dev, "power");
Re: [PATCH] backlight: pwm_bl: Fix GPIO out for unimplemented .get_direction()
On 03/22/2017 07:21 PM, Geert Uytterhoeven wrote:
Commit 7613c922315e308a ("backlight: pwm_bl: Move the checks for initial
power state to a separate function") not just moved some code, but made
slight changes in semantics.
If a gpiochip doesn't implement the optional .get_direction() callback,
gpiod_get_direction always returns -EINVAL, which is never equal to
GPIOF_DIR_IN, leading to the GPIO not being configured for output.
The platforms I have tested the gpio drivers do implement the get_direction()
callback and I was not aware of this behaviour.
To avoid this, invert the test and check for not GPIOF_DIR_OUT instead,
like the original code did.
This restores the display on r8a7740/armadillo.
Fixes: 7613c922315e308a ("backlight: pwm_bl: Move the checks for initial power state
to a separate function")
Signed-off-by: Geert Uytterhoeven
Reviewed-by: Peter Ujfalusi
---
drivers/video/backlight/pwm_bl.c | 7 ---
1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/drivers/video/backlight/pwm_bl.c b/drivers/video/backlight/pwm_bl.c
index d7efcb632f7d9dde..002f1ce22bd02032 100644
--- a/drivers/video/backlight/pwm_bl.c
+++ b/drivers/video/backlight/pwm_bl.c
@@ -297,14 +297,15 @@ static int pwm_backlight_probe(struct platform_device
*pdev)
}
/*
-* If the GPIO is configured as input, change the direction to output
-* and set the GPIO as active.
+* If the GPIO is not known to be already configured as output, that
+* is, if gpiod_get_direction returns either GPIOF_DIR_IN or -EINVAL,
+* change the direction to output and set the GPIO as active.
* Do not force the GPIO to active when it was already output as it
* could cause backlight flickering or we would enable the backlight too
* 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_OUT)
gpiod_direction_output(pb->enable_gpio, 1);
pb->power_supply = devm_regulator_get(>dev, "power");
--
Péter
Re: [PATCH] backlight: pwm_bl: Fix GPIO out for unimplemented .get_direction()
On 03/22/2017 07:21 PM, Geert Uytterhoeven wrote:
Commit 7613c922315e308a ("backlight: pwm_bl: Move the checks for initial
power state to a separate function") not just moved some code, but made
slight changes in semantics.
If a gpiochip doesn't implement the optional .get_direction() callback,
gpiod_get_direction always returns -EINVAL, which is never equal to
GPIOF_DIR_IN, leading to the GPIO not being configured for output.
The platforms I have tested the gpio drivers do implement the get_direction()
callback and I was not aware of this behaviour.
To avoid this, invert the test and check for not GPIOF_DIR_OUT instead,
like the original code did.
This restores the display on r8a7740/armadillo.
Fixes: 7613c922315e308a ("backlight: pwm_bl: Move the checks for initial power state
to a separate function")
Signed-off-by: Geert Uytterhoeven
Reviewed-by: Peter Ujfalusi
---
drivers/video/backlight/pwm_bl.c | 7 ---
1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/drivers/video/backlight/pwm_bl.c b/drivers/video/backlight/pwm_bl.c
index d7efcb632f7d9dde..002f1ce22bd02032 100644
--- a/drivers/video/backlight/pwm_bl.c
+++ b/drivers/video/backlight/pwm_bl.c
@@ -297,14 +297,15 @@ static int pwm_backlight_probe(struct platform_device
*pdev)
}
/*
-* If the GPIO is configured as input, change the direction to output
-* and set the GPIO as active.
+* If the GPIO is not known to be already configured as output, that
+* is, if gpiod_get_direction returns either GPIOF_DIR_IN or -EINVAL,
+* change the direction to output and set the GPIO as active.
* Do not force the GPIO to active when it was already output as it
* could cause backlight flickering or we would enable the backlight too
* 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_OUT)
gpiod_direction_output(pb->enable_gpio, 1);
pb->power_supply = devm_regulator_get(>dev, "power");
--
Péter
