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Message-ID: <9a3a51f8-e772-4e54-a9be-5801ff6edf7a@quicinc.com>
Date: Fri, 16 Feb 2024 13:21:18 -0800
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Subject: Re: [PATCH] drm/panel: boe-tv101wum-nl6: make use of
 prepare_prev_first
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To: Douglas Anderson <dianders@chromium.org>,
        <dri-devel@lists.freedesktop.org>
CC: Stephen Boyd <swboyd@chromium.org>,
        Abhinav Kumar
	<quic_abhinavk@quicinc.com>,
        Daniel Vetter <daniel@ffwll.ch>, David Airlie
	<airlied@gmail.com>,
        Dmitry Baryshkov <dmitry.baryshkov@linaro.org>,
        "Maarten
 Lankhorst" <maarten.lankhorst@linux.intel.com>,
        Maxime Ripard
	<mripard@kernel.org>,
        Neil Armstrong <neil.armstrong@linaro.org>,
        "Sam
 Ravnborg" <sam@ravnborg.org>,
        Thomas Zimmermann <tzimmermann@suse.de>,
        <linux-kernel@vger.kernel.org>
References: <20240216123111.1.I71c103720909790e1ec5a3f5bd96b18ab7b596fa@changeid>
From: Jessica Zhang <quic_jesszhan@quicinc.com>
In-Reply-To: <20240216123111.1.I71c103720909790e1ec5a3f5bd96b18ab7b596fa@changeid>
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On 2/16/2024 12:31 PM, Douglas Anderson wrote:
> The panel on sc7180-trogdor-wormdingler and
> sc7180-trogdor-quackingstick hasn't been coming up since commit
> 9e15123eca79 ("drm/msm/dsi: Stop unconditionally powering up DSI hosts
> at modeset"). Let's add "prepare_prev_first" as has been done for many
> other DSI panels.
> 
> Fixes: 9e15123eca79 ("drm/msm/dsi: Stop unconditionally powering up DSI hosts at modeset")
> Signed-off-by: Douglas Anderson <dianders@chromium.org>

Hi Doug,

Reviewed-by: Jessica Zhang <quic_jesszhan@quicinc.com>

Thanks,

Jessica Zhang

> ---
> This of course gets into debates about getting a nicer solution that
> doesn't involve adding "prepare_prev_first" to every DSI panel out
> there, maybe building on Dmitry's work [1]. While it would be nice if
> we could get there, getting this landed is easy to backport to stable
> trees and gets the panel working again.
> 
> [1] https://lore.kernel.org/r/20231016165355.1327217-4-dmitry.baryshkov@linaro.org
> 
>   drivers/gpu/drm/panel/panel-boe-tv101wum-nl6.c | 2 ++
>   1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/gpu/drm/panel/panel-boe-tv101wum-nl6.c b/drivers/gpu/drm/panel/panel-boe-tv101wum-nl6.c
> index c4c0f08e9202..bc08814954f9 100644
> --- a/drivers/gpu/drm/panel/panel-boe-tv101wum-nl6.c
> +++ b/drivers/gpu/drm/panel/panel-boe-tv101wum-nl6.c
> @@ -1871,6 +1871,8 @@ static int boe_panel_add(struct boe_panel *boe)
>   
>   	gpiod_set_value(boe->enable_gpio, 0);
>   
> +	boe->base.prepare_prev_first = true;
> +
>   	drm_panel_init(&boe->base, dev, &boe_panel_funcs,
>   		       DRM_MODE_CONNECTOR_DSI);
>   	err = of_drm_get_panel_orientation(dev->of_node, &boe->orientation);
> -- 
> 2.44.0.rc0.258.g7320e95886-goog
>