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From: Lee Jones <lee@kernel.org>
To: "Uwe Kleine-König" <u.kleine-koenig@pengutronix.de>
Cc: Daniel Thompson <daniel.thompson@linaro.org>,
	Jingoo Han <jingoohan1@gmail.com>,
	Thierry Reding <thierry.reding@gmail.com>,
	Helge Deller <deller@gmx.de>,
	linux-pwm@vger.kernel.org, dri-devel@lists.freedesktop.org,
	linux-fbdev@vger.kernel.org, kernel@pengutronix.de
Subject: Re: [PATCH v2 1/2] backlight: pwm_bl: Configure pwm only once per backlight toggle
Date: Fri, 20 Jan 2023 17:07:06 +0000	[thread overview]
Message-ID: <Y8rKOozBnOGg2Sxg@google.com> (raw)
In-Reply-To: <20230120120018.161103-2-u.kleine-koenig@pengutronix.de>

On Fri, 20 Jan 2023, Uwe Kleine-König wrote:

> When the function pwm_backlight_update_status() was called with
> brightness > 0, pwm_get_state() was called twice (once directly and once
> in compute_duty_cycle). Also pwm_apply_state() was called twice (once in
> pwm_backlight_power_on() and once directly).
> 
> Optimize this to do both calls only once.
> 
> Note that with this affects the order of regulator and PWM setup. It's
> not expected to have a relevant effect on hardware. The rationale for
> this is that the regulator (and the GPIO) are reasonable to switch in
> pwm_backlight_power_on()/pwm_backlight_power_off() but the PWM has
> nothing to do with power. (The post_pwm_on_delay and pwm_off_delay are
> still there though.)
> 
> Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>
> Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
> ---
>  drivers/video/backlight/pwm_bl.c | 28 ++++++++++------------------
>  1 file changed, 10 insertions(+), 18 deletions(-)

Applied, thanks

-- 
Lee Jones [李琼斯]

WARNING: multiple messages have this Message-ID (diff)
From: Lee Jones <lee@kernel.org>
To: "Uwe Kleine-König" <u.kleine-koenig@pengutronix.de>
Cc: linux-pwm@vger.kernel.org,
	Daniel Thompson <daniel.thompson@linaro.org>,
	Jingoo Han <jingoohan1@gmail.com>, Helge Deller <deller@gmx.de>,
	linux-fbdev@vger.kernel.org, dri-devel@lists.freedesktop.org,
	Thierry Reding <thierry.reding@gmail.com>,
	kernel@pengutronix.de
Subject: Re: [PATCH v2 1/2] backlight: pwm_bl: Configure pwm only once per backlight toggle
Date: Fri, 20 Jan 2023 17:07:06 +0000	[thread overview]
Message-ID: <Y8rKOozBnOGg2Sxg@google.com> (raw)
In-Reply-To: <20230120120018.161103-2-u.kleine-koenig@pengutronix.de>

On Fri, 20 Jan 2023, Uwe Kleine-König wrote:

> When the function pwm_backlight_update_status() was called with
> brightness > 0, pwm_get_state() was called twice (once directly and once
> in compute_duty_cycle). Also pwm_apply_state() was called twice (once in
> pwm_backlight_power_on() and once directly).
> 
> Optimize this to do both calls only once.
> 
> Note that with this affects the order of regulator and PWM setup. It's
> not expected to have a relevant effect on hardware. The rationale for
> this is that the regulator (and the GPIO) are reasonable to switch in
> pwm_backlight_power_on()/pwm_backlight_power_off() but the PWM has
> nothing to do with power. (The post_pwm_on_delay and pwm_off_delay are
> still there though.)
> 
> Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>
> Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
> ---
>  drivers/video/backlight/pwm_bl.c | 28 ++++++++++------------------
>  1 file changed, 10 insertions(+), 18 deletions(-)

Applied, thanks

-- 
Lee Jones [李琼斯]

  reply	other threads:[~2023-01-20 17:07 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-01-20 12:00 [PATCH v2 0/2] backlight: pwm_bl: Two PWM releated changes Uwe Kleine-König
2023-01-20 12:00 ` Uwe Kleine-König
2023-01-20 12:00 ` [PATCH v2 1/2] backlight: pwm_bl: Configure pwm only once per backlight toggle Uwe Kleine-König
2023-01-20 12:00   ` Uwe Kleine-König
2023-01-20 17:07   ` Lee Jones [this message]
2023-01-20 17:07     ` Lee Jones
2023-01-20 12:00 ` [PATCH v2 2/2] backlight: pwm_bl: Don't rely on a disabled PWM emiting inactive state Uwe Kleine-König
2023-01-20 12:00   ` Uwe Kleine-König
2023-01-20 15:04   ` Daniel Thompson
2023-01-20 15:04     ` Daniel Thompson
2023-01-20 17:07   ` Lee Jones
2023-01-20 17:07     ` Lee Jones
2023-03-22  5:13 [PATCH v2 1/2] backlight: pwm_bl: Configure pwm only once per backlight toggle Aisheng Dong

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