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Date:   Mon, 9 Jan 2023 12:25:45 +0100
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Subject: Re: [PATCH 2/2] drm/panel: boe-tv101wum-nl6: Reduce lcm_reset to send
 initial code time
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To:     xinlei.lee@mediatek.com, chunkuang.hu@kernel.org,
        p.zabel@pengutronix.de, airlied@linux.ie, daniel@ffwll.ch,
        matthias.bgg@gmail.com, jitao.shi@mediatek.com,
        thierry.reding@gmail.com, sam@ravnborg.org
Cc:     dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org,
        linux-arm-kernel@lists.infradead.org,
        linux-mediatek@lists.infradead.org,
        Project_Global_Chrome_Upstream_Group@mediatek.com
References: <1672974321-18947-1-git-send-email-xinlei.lee@mediatek.com>
 <1672974321-18947-3-git-send-email-xinlei.lee@mediatek.com>
From:   AngeloGioacchino Del Regno 
        <angelogioacchino.delregno@collabora.com>
In-Reply-To: <1672974321-18947-3-git-send-email-xinlei.lee@mediatek.com>
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Il 06/01/23 04:05, xinlei.lee@mediatek.com ha scritto:
> From: Xinlei Lee <xinlei.lee@mediatek.com>
> 
> Since the panel spec stipulates that the time from lcm_reset to DSI to
> send the initial code should be greater than 6ms and less than 40ms,
> so reduce the delay before sending the initial code and avoid panel
> exceptions.
> 
> Fixes: a869b9db7adf ("drm/panel: support for boe tv101wum-nl6 wuxga dsi video mode panel")
> Signed-off-by: Xinlei Lee <xinlei.lee@mediatek.com>
> ---
>   drivers/gpu/drm/panel/panel-boe-tv101wum-nl6.c | 1 -
>   1 file changed, 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/panel/panel-boe-tv101wum-nl6.c b/drivers/gpu/drm/panel/panel-boe-tv101wum-nl6.c
> index 857a2f0420d7..f0093035f1ff 100644
> --- a/drivers/gpu/drm/panel/panel-boe-tv101wum-nl6.c
> +++ b/drivers/gpu/drm/panel/panel-boe-tv101wum-nl6.c
> @@ -780,7 +780,6 @@ static const struct panel_init_cmd inx_hj110iz_init_cmd[] = {
>   };
>   
>   static const struct panel_init_cmd boe_init_cmd[] = {
> -	_INIT_DELAY_CMD(24),

You said that should be greater than 6 and less than 40: perhaps on MediaTek
platforms removing this delay is fine but we don't know about others - and this
driver is for all platforms.

To stay on the safe side you should, at this point, replace this delay with

	_INIT_DELAY_CMD(7);

Regards,
Angelo