Re: [PATCH 1/2] drm/mediatek: dsi: Reduce the time of dsi from LP11 to sending cmd

From: AngeloGioacchino Del Regno
Date: Mon Jan 09 2023 - 06:27:17 EST


Il 06/01/23 04:05, xinlei.lee@xxxxxxxxxxxx ha scritto:
From: Xinlei Lee <xinlei.lee@xxxxxxxxxxxx>

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@xxxxxxxxxxxx>

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