* [PATCH v3] backlight: pwm_bl: Fix brightness levels for non-DT case.
@ 2018-11-07 8:55 Enric Balletbo i Serra
2018-11-30 22:22 ` Enric Balletbo Serra
0 siblings, 1 reply; 3+ messages in thread
From: Enric Balletbo i Serra @ 2018-11-07 8:55 UTC (permalink / raw)
To: linux-kernel, robert.jarzmik, daniel.thompson, lee.jones
Cc: kernel, heiko, stable, u.kleine-koenig, linux-pwm, linux-fbdev,
Thierry Reding, Bartlomiej Zolnierkiewicz, dri-devel, Jingoo Han
Commit '88ba95bedb79 ("backlight: pwm_bl: Compute brightness of LED
linearly to human eye")' allows the possibility to compute a default
brightness table when there isn't the brightness-levels property in the
DT. Unfortunately the changes made broke the pwm backlight for the
non-DT boards.
Usually, the non-DT boards don't pass the brightness levels via platform
data, instead, it sets the max_brightness in their platform data and the
driver calculates the level without a table. The offending patch assumed
that when there is no brightness levels table we should create one, but this
is clearly wrong for the non-DT case.
After this patch the code handles the DT and the non-DT case taking in
consideration also if max_brightness is set or not.
Fixes: 88ba95bedb79 ("backlight: pwm_bl: Compute brightness of LED linearly to human eye")
Cc: <stable@vger.kernel.org>
Reported-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Tested-by: Robert Jarzmik <robert.jarzmik@free.fr>
Acked-by: Daniel Thompson <daniel.thompson@linaro.org>
---
Changes in v3:
- Fixed some typos in commit message.
- Removed ' in Fixes tag.
Changes in v2:
- Rebase on top of mainline
- Add Tested-by and Acked-by tags.
drivers/video/backlight/pwm_bl.c | 41 +++++++++++++++++++++++++++-----
1 file changed, 35 insertions(+), 6 deletions(-)
diff --git a/drivers/video/backlight/pwm_bl.c b/drivers/video/backlight/pwm_bl.c
index 678b27063198..f9ef0673a083 100644
--- a/drivers/video/backlight/pwm_bl.c
+++ b/drivers/video/backlight/pwm_bl.c
@@ -562,7 +562,30 @@ static int pwm_backlight_probe(struct platform_device *pdev)
goto err_alloc;
}
- if (!data->levels) {
+ if (data->levels) {
+ /*
+ * For the DT case, only when brightness levels is defined
+ * data->levels is filled. For the non-DT case, data->levels
+ * can come from platform data, however is not usual.
+ */
+ for (i = 0; i <= data->max_brightness; i++) {
+ if (data->levels[i] > pb->scale)
+ pb->scale = data->levels[i];
+
+ pb->levels = data->levels;
+ }
+ } else if (!data->max_brightness) {
+ /*
+ * If no brightness levels are provided and max_brightness is
+ * not set, use the default brightness table. For the DT case,
+ * max_brightness is set to 0 when brightness levels is not
+ * specified. For the non-DT case, max_brightness is usually
+ * set to some value.
+ */
+
+ /* Get the PWM period (in nanoseconds) */
+ pwm_get_state(pb->pwm, &state);
+
ret = pwm_backlight_brightness_default(&pdev->dev, data,
state.period);
if (ret < 0) {
@@ -570,13 +593,19 @@ static int pwm_backlight_probe(struct platform_device *pdev)
"failed to setup default brightness table\n");
goto err_alloc;
}
- }
- for (i = 0; i <= data->max_brightness; i++) {
- if (data->levels[i] > pb->scale)
- pb->scale = data->levels[i];
+ for (i = 0; i <= data->max_brightness; i++) {
+ if (data->levels[i] > pb->scale)
+ pb->scale = data->levels[i];
- pb->levels = data->levels;
+ pb->levels = data->levels;
+ }
+ } else {
+ /*
+ * That only happens for the non-DT case, where platform data
+ * sets the max_brightness value.
+ */
+ pb->scale = data->max_brightness;
}
pb->lth_brightness = data->lth_brightness * (state.period / pb->scale);
--
2.19.1
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH v3] backlight: pwm_bl: Fix brightness levels for non-DT case.
2018-11-07 8:55 [PATCH v3] backlight: pwm_bl: Fix brightness levels for non-DT case Enric Balletbo i Serra
@ 2018-11-30 22:22 ` Enric Balletbo Serra
2018-12-03 7:07 ` Lee Jones
0 siblings, 1 reply; 3+ messages in thread
From: Enric Balletbo Serra @ 2018-11-30 22:22 UTC (permalink / raw)
To: Enric Balletbo i Serra
Cc: linux-kernel, robert.jarzmik, Daniel Thompson, Lee Jones, kernel,
Heiko Stübner, stable, u.kleine-koenig, Linux PWM List,
linux-fbdev, Thierry Reding, Bartlomiej Zolnierkiewicz,
dri-devel, Jingoo Han
Hi,
Missatge de Enric Balletbo i Serra <enric.balletbo@collabora.com> del
dia dc., 7 de nov. 2018 a les 9:56:
>
> Commit '88ba95bedb79 ("backlight: pwm_bl: Compute brightness of LED
> linearly to human eye")' allows the possibility to compute a default
> brightness table when there isn't the brightness-levels property in the
> DT. Unfortunately the changes made broke the pwm backlight for the
> non-DT boards.
>
> Usually, the non-DT boards don't pass the brightness levels via platform
> data, instead, it sets the max_brightness in their platform data and the
> driver calculates the level without a table. The offending patch assumed
> that when there is no brightness levels table we should create one, but this
> is clearly wrong for the non-DT case.
>
> After this patch the code handles the DT and the non-DT case taking in
> consideration also if max_brightness is set or not.
>
> Fixes: 88ba95bedb79 ("backlight: pwm_bl: Compute brightness of LED linearly to human eye")
> Cc: <stable@vger.kernel.org>
> Reported-by: Robert Jarzmik <robert.jarzmik@free.fr>
> Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
> Tested-by: Robert Jarzmik <robert.jarzmik@free.fr>
> Acked-by: Daniel Thompson <daniel.thompson@linaro.org>
> ---
>
> Changes in v3:
> - Fixed some typos in commit message.
> - Removed ' in Fixes tag.
>
> Changes in v2:
> - Rebase on top of mainline
> - Add Tested-by and Acked-by tags.
>
> drivers/video/backlight/pwm_bl.c | 41 +++++++++++++++++++++++++++-----
> 1 file changed, 35 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/video/backlight/pwm_bl.c b/drivers/video/backlight/pwm_bl.c
> index 678b27063198..f9ef0673a083 100644
> --- a/drivers/video/backlight/pwm_bl.c
> +++ b/drivers/video/backlight/pwm_bl.c
> @@ -562,7 +562,30 @@ static int pwm_backlight_probe(struct platform_device *pdev)
> goto err_alloc;
> }
>
> - if (!data->levels) {
> + if (data->levels) {
> + /*
> + * For the DT case, only when brightness levels is defined
> + * data->levels is filled. For the non-DT case, data->levels
> + * can come from platform data, however is not usual.
> + */
> + for (i = 0; i <= data->max_brightness; i++) {
> + if (data->levels[i] > pb->scale)
> + pb->scale = data->levels[i];
> +
> + pb->levels = data->levels;
> + }
> + } else if (!data->max_brightness) {
> + /*
> + * If no brightness levels are provided and max_brightness is
> + * not set, use the default brightness table. For the DT case,
> + * max_brightness is set to 0 when brightness levels is not
> + * specified. For the non-DT case, max_brightness is usually
> + * set to some value.
> + */
> +
> + /* Get the PWM period (in nanoseconds) */
> + pwm_get_state(pb->pwm, &state);
> +
> ret = pwm_backlight_brightness_default(&pdev->dev, data,
> state.period);
> if (ret < 0) {
> @@ -570,13 +593,19 @@ static int pwm_backlight_probe(struct platform_device *pdev)
> "failed to setup default brightness table\n");
> goto err_alloc;
> }
> - }
>
> - for (i = 0; i <= data->max_brightness; i++) {
> - if (data->levels[i] > pb->scale)
> - pb->scale = data->levels[i];
> + for (i = 0; i <= data->max_brightness; i++) {
> + if (data->levels[i] > pb->scale)
> + pb->scale = data->levels[i];
>
> - pb->levels = data->levels;
> + pb->levels = data->levels;
> + }
> + } else {
> + /*
> + * That only happens for the non-DT case, where platform data
> + * sets the max_brightness value.
> + */
> + pb->scale = data->max_brightness;
> }
>
> pb->lth_brightness = data->lth_brightness * (state.period / pb->scale);
> --
> 2.19.1
>
A gentle ping on this patch.
Best regards,
Enric
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH v3] backlight: pwm_bl: Fix brightness levels for non-DT case.
2018-11-30 22:22 ` Enric Balletbo Serra
@ 2018-12-03 7:07 ` Lee Jones
0 siblings, 0 replies; 3+ messages in thread
From: Lee Jones @ 2018-12-03 7:07 UTC (permalink / raw)
To: Enric Balletbo Serra
Cc: Enric Balletbo i Serra, linux-kernel, robert.jarzmik,
Daniel Thompson, kernel, Heiko Stübner, stable,
u.kleine-koenig, Linux PWM List, linux-fbdev, Thierry Reding,
Bartlomiej Zolnierkiewicz, dri-devel, Jingoo Han
On Fri, 30 Nov 2018, Enric Balletbo Serra wrote:
> Hi,
> Missatge de Enric Balletbo i Serra <enric.balletbo@collabora.com> del
> dia dc., 7 de nov. 2018 a les 9:56:
> >
> > Commit '88ba95bedb79 ("backlight: pwm_bl: Compute brightness of LED
> > linearly to human eye")' allows the possibility to compute a default
> > brightness table when there isn't the brightness-levels property in the
> > DT. Unfortunately the changes made broke the pwm backlight for the
> > non-DT boards.
> >
> > Usually, the non-DT boards don't pass the brightness levels via platform
> > data, instead, it sets the max_brightness in their platform data and the
> > driver calculates the level without a table. The offending patch assumed
> > that when there is no brightness levels table we should create one, but this
> > is clearly wrong for the non-DT case.
> >
> > After this patch the code handles the DT and the non-DT case taking in
> > consideration also if max_brightness is set or not.
> >
> > Fixes: 88ba95bedb79 ("backlight: pwm_bl: Compute brightness of LED linearly to human eye")
> > Cc: <stable@vger.kernel.org>
> > Reported-by: Robert Jarzmik <robert.jarzmik@free.fr>
> > Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
> > Tested-by: Robert Jarzmik <robert.jarzmik@free.fr>
> > Acked-by: Daniel Thompson <daniel.thompson@linaro.org>
> > ---
> >
> > Changes in v3:
> > - Fixed some typos in commit message.
> > - Removed ' in Fixes tag.
> >
> > Changes in v2:
> > - Rebase on top of mainline
> > - Add Tested-by and Acked-by tags.
> >
> > drivers/video/backlight/pwm_bl.c | 41 +++++++++++++++++++++++++++-----
> > 1 file changed, 35 insertions(+), 6 deletions(-)
[...]
> A gentle ping on this patch.
Don't do that.
If you think that it's been forgotten, send it again as a [RESEND].
--
Lee Jones [李琼斯]
Linaro Services Technical Lead
Linaro.org │ Open source software for ARM SoCs
Follow Linaro: Facebook | Twitter | Blog
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2018-11-07 8:55 [PATCH v3] backlight: pwm_bl: Fix brightness levels for non-DT case Enric Balletbo i Serra
2018-11-30 22:22 ` Enric Balletbo Serra
2018-12-03 7:07 ` Lee Jones
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