From: Daniel Thompson <daniel.thompson@linaro.org>
To: "Uwe Kleine-König" <u.kleine-koenig@pengutronix.de>
Cc: Lee Jones <lee@kernel.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,
Aisheng Dong <aisheng.dong@nxp.com>,
Aisheng Dong <asheng.dong@nxp.com>
Subject: Re: [PATCH v2] backlight: pwm_bl: Disable PWM on shutdown and suspend
Date: Tue, 26 Sep 2023 12:11:37 +0100 [thread overview]
Message-ID: <20230926111137.GA4356@aspen.lan> (raw)
In-Reply-To: <20230926084612.2074692-1-u.kleine-koenig@pengutronix.de>
On Tue, Sep 26, 2023 at 10:46:12AM +0200, Uwe Kleine-König wrote:
> Since commit 00e7e698bff1 ("backlight: pwm_bl: Configure pwm only once
> per backlight toggle") calling pwm_backlight_power_off() doesn't disable
> the PWM any more. However this is necessary to suspend because PWM
> drivers usually refuse to suspend if they are still enabled.
>
> Also adapt shutdown to disable the PWM for similar reasons.
>
> Fixes: 00e7e698bff1 ("backlight: pwm_bl: Configure pwm only once per backlight toggle")
> Reported-by: Aisheng Dong <aisheng.dong@nxp.com>
> Tested-by: Aisheng Dong <asheng.dong@nxp.com>
> Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Changes proposed look good (and the comment about badly designed boards
going to HiZ state we super helpful).
Only thing from my is why there is no attempt to disable the PWM
from the .remove_new() callback.
Daniel.
prev parent reply other threads:[~2023-09-26 11:11 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-09-26 8:46 [PATCH v2] backlight: pwm_bl: Disable PWM on shutdown and suspend Uwe Kleine-König
2023-09-26 8:53 ` Uwe Kleine-König
2023-09-26 9:16 ` Lee Jones
2023-09-26 11:11 ` Daniel Thompson [this message]
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