Re: [PATCH v3,1/4] drm/mediatek: Adjust the timing of mipi signal from LP00 to LP11

From: Rex-BC Chen
Date: Thu Mar 17 2022 - 07:13:31 EST


Hello Xinlei,

Thanks for your patch, and there are something I want to know:

On Thu, 2022-03-17 at 15:53 +0800, xinlei.lee@xxxxxxxxxxxx wrote:
> From: Jitao Shi <jitao.shi@xxxxxxxxxxxx>
>
> Old sequence:
> 1. Pull the MIPI signal high
> 2. Delay & Dsi_reset
> 3. Set the dsi timing register
> 4. dsi clk & lanes leave ulp mode and enter hs mode
>
> New sequence:
> 1. Set the dsi timing register
> 2. Pull the MIPI signal high
> 3. Delay & Dsi_reset
> 4. dsi clk & lanes leave ulp mode and enter hs mode
>

Could you explain why you want to change original power on sequence?
>From this commit message, I don't know why you want to do this.
If the reason is in cover letter, I think you should move them here.

> In the new sequence 2 & 3 & 4 will be moved to dsi_enbale in later
> patch.

I think this is no need to describe here.

BRs,
Rex
>
> Signed-off-by: Jitao Shi <jitao.shi@xxxxxxxxxxxx>
> Signed-off-by: Xinlei Lee <xinlei.lee@xxxxxxxxxxxx>
> ---
> drivers/gpu/drm/mediatek/mtk_dsi.c | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/mediatek/mtk_dsi.c
> b/drivers/gpu/drm/mediatek/mtk_dsi.c
> index ccb0511b9cd5..262c027d8c2f 100644
> --- a/drivers/gpu/drm/mediatek/mtk_dsi.c
> +++ b/drivers/gpu/drm/mediatek/mtk_dsi.c
> @@ -649,14 +649,14 @@ static int mtk_dsi_poweron(struct mtk_dsi *dsi)
> mtk_dsi_reset_engine(dsi);
> mtk_dsi_phy_timconfig(dsi);
>
> - mtk_dsi_rxtx_control(dsi);
> - usleep_range(30, 100);
> - mtk_dsi_reset_dphy(dsi);
> mtk_dsi_ps_control_vact(dsi);
> mtk_dsi_set_vm_cmd(dsi);
> mtk_dsi_config_vdo_timing(dsi);
> mtk_dsi_set_interrupt_enable(dsi);
>
> + mtk_dsi_rxtx_control(dsi);
> + usleep_range(30, 100);
> + mtk_dsi_reset_dphy(dsi);
> mtk_dsi_clk_ulp_mode_leave(dsi);
> mtk_dsi_lane0_ulp_mode_leave(dsi);
> mtk_dsi_clk_hs_mode(dsi, 0);