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Date:   Wed, 1 Jul 2020 18:04:44 +0200
From:   Guido =?iso-8859-1?Q?G=FCnther?= <guido.gunther@puri.sm>
To:     Ondrej Jirman <megous@megous.com>
Cc:     linux-sunxi@googlegroups.com,
        Thierry Reding <thierry.reding@gmail.com>,
        Sam Ravnborg <sam@ravnborg.org>,
        David Airlie <airlied@linux.ie>,
        Daniel Vetter <daniel@ffwll.ch>,
        Purism Kernel Team <kernel@puri.sm>,
        Rob Herring <robh+dt@kernel.org>,
        Maxime Ripard <mripard@kernel.org>,
        Chen-Yu Tsai <wens@csie.org>,
        Linus Walleij <linus.walleij@linaro.org>,
        Icenowy Zheng <icenowy@aosc.io>,
        dri-devel@lists.freedesktop.org, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
        Samuel Holland <samuel@sholland.org>,
        Martijn Braam <martijn@brixit.nl>, Luca Weiss <luca@z3ntu.xyz>,
        Bhushan Shah <bshah@kde.org>
Subject: Re: [PATCH v6 11/13] drm/panel: st7703: Assert reset prior to
 powering down the regulators
Message-ID: <20200701160444.GJ174356@bogon.m.sigxcpu.org>
References: <20200701103126.1512615-1-megous@megous.com>
 <20200701103126.1512615-12-megous@megous.com>
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In-Reply-To: <20200701103126.1512615-12-megous@megous.com>
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Hi,
On Wed, Jul 01, 2020 at 12:31:24PM +0200, Ondrej Jirman wrote:
> The reset pin is inverted, so if we don't assert reset, the actual gpio
> will be high and may keep driving the IO port of the panel.

Reviewed-by: Guido G?nther <agx@sigxcpu.org>

> 
> Signed-off-by: Ondrej Jirman <megous@megous.com>
> Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
> ---
>  drivers/gpu/drm/panel/panel-sitronix-st7703.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/gpu/drm/panel/panel-sitronix-st7703.c b/drivers/gpu/drm/panel/panel-sitronix-st7703.c
> index 0c4167994d01..e303b7b1a215 100644
> --- a/drivers/gpu/drm/panel/panel-sitronix-st7703.c
> +++ b/drivers/gpu/drm/panel/panel-sitronix-st7703.c
> @@ -417,6 +417,7 @@ static int st7703_unprepare(struct drm_panel *panel)
>  	if (!ctx->prepared)
>  		return 0;
>  
> +	gpiod_set_value_cansleep(ctx->reset_gpio, 1);
>  	regulator_disable(ctx->iovcc);
>  	regulator_disable(ctx->vcc);
>  	ctx->prepared = false;
> -- 
> 2.27.0
>