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Date:   Mon, 9 Jan 2023 12:26:24 +0100
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Subject: Re: [PATCH 1/2] drm/mediatek: dsi: Reduce the time of dsi from LP11
 to sending cmd
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>
 <1672974321-18947-2-git-send-email-xinlei.lee@mediatek.com>
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From:   AngeloGioacchino Del Regno 
        <angelogioacchino.delregno@collabora.com>
In-Reply-To: <1672974321-18947-2-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>
> 
> According to Figure 16 Turnaround Procedure on page 36 in [1], you
> can see the status of LP-00 -> LP10 -> LP11. This state can correspond
> to the state of DSI from LP00 -> LP11 in mtk_dsi_lane_ready function
> in mtk_dsi.c.
> 
> LP-00 -> LP10 -> LP11 takes about 2*TLPX time (refer to [1] page 51
> to see that TLPX is 50ns).
> 
> The delay at the end of the mtk_dsi_lane_ready function should be
> greater than the 2*TLPX specified by the DSI spec, and less than
> the time specified by the DSI_RX (generally 6ms to 40ms), to avoid
> problems caused by the RX specification.
> 
> [1]:mipi_D-PHY_specification_v1-1
> 
> Fixes: 39e8d062b03c ("drm/mediatek: Keep dsi as LP00 before dcs cmds transfer")
> Signed-off-by: Xinlei Lee <xinlei.lee@mediatek.com>

Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>