Hi, Xinlei: <xinlei.lee@xxxxxxxxxxxx> 於 2023年1月10日 週二 下午1:55寫道： > > 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 Applied to mediatek-drm-next [1], thanks. [1] https://git.kernel.org/pub/scm/linux/kernel/git/chunkuang.hu/linux.git/log/?h=mediatek-drm-next Regards, Chun-Kuang. > > [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> > Acked-by: Sam Ravnborg <sam@xxxxxxxxxxxx> > Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@xxxxxxxxxxxxx> > --- > drivers/gpu/drm/mediatek/mtk_dsi.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/mediatek/mtk_dsi.c b/drivers/gpu/drm/mediatek/mtk_dsi.c > index 3b7d13028fb6..9e1363c9fcdb 100644 > --- a/drivers/gpu/drm/mediatek/mtk_dsi.c > +++ b/drivers/gpu/drm/mediatek/mtk_dsi.c > @@ -721,7 +721,7 @@ static void mtk_dsi_lane_ready(struct mtk_dsi *dsi) > mtk_dsi_clk_ulp_mode_leave(dsi); > mtk_dsi_lane0_ulp_mode_leave(dsi); > mtk_dsi_clk_hs_mode(dsi, 0); > - msleep(20); > + usleep_range(1000, 3000); > /* The reaction time after pulling up the mipi signal for dsi_rx */ > } > } > -- > 2.18.0 >
