RE: panel: panel-raydium68200 driver fails to write MIPI DSI init commands

[Philippe CORNU <philippe.cornu@st.com>]

Dear Aleksandr,

We use the raydium68200 ic driver in a dsi 720p 2dl panel module mounted on the MB1230 board [1], mounted on the STM32MP157 eval board [2].

According to your email, you are using the EDT ETML0500F3DHA panel module, probably composed of a raydium68200+a touchscreen+a glass+backlight+.... 

Could you please double check if your panel module has the same characteristics as the one described in panel-raydium68200.c (pixel clock, blanking values, resolutions, number of dsi data lanes, enable & reset gpios, backlight...).

Moreover, maybe your panel embeds a non-volatile ram which contains nice default values ("fused" during production) allowing to reduce a lot the panel init sequence... allowing then to use panel-simple.c instead of panel-raydium68200.c (that could explain why you can see "colors" without sending any init sequence).

The issues you encountered may come from (starting with the highest probability):
* bad lcd hw vs sw configuration (see description above).
* bad pixel clock frequency, bad blanking values...
* bad dsi internal Rockchip ip programming (pll and clock trees in dt...)

Hope it helps,

[1] https://wiki.st.com/stm32mpu/wiki/MB1230
[2] https://www.st.com/en/evaluation-tools/stm32mp157a-ev1.html

Philippe :-)

-----Original Message-----
From: aleksandr.o.makarov@gmail.com <aleksandr.o.makarov@gmail.com> 
Sent: Saturday, January 16, 2021 12:40
To: Andrzej Hajda <a.hajda@samsung.com>; Neil Armstrong <narmstrong@baylibre.com>; Laurent Pinchart <Laurent.pinchart@ideasonboard.com>; Jonas Karlman <jonas@kwiboo.se>; Jernej Skrabec <jernej.skrabec@siol.net>; David Airlie <airlied@linux.ie>; Daniel Vetter <daniel@ffwll.ch>; Sam Ravnborg <sam@ravnborg.org>; Philippe CORNU <philippe.cornu@st.com>; Antonio BORNEO <antonio.borneo@st.com>; <dri-devel@lists.freedesktop.org> <linux-kernel@vger.kernel.org>
Subject: drm: panel: panel-raydium68200 driver fails to write MIPI DSI init commands

I need to bring up my MIPI DSI 1280x720 EDT ETML0500F3DHA panel on a
RockPro64 V2.1 board.

There is no completely suitable in-tree driver for that panel yet, but for the purpose of reproducing the issue that I face, the gpu/drm/panel/panel-raydium-rm68200.c can do just fine.

To reproduce:

- Get the same Linux 5.9.14 as on my RockPro64 board (with Armbian
20.11.6 on it)

- Patch the rk3399-rockpro64.dts to add a panel node that is compatible with "raydium,rm68200" driver on MIPI interface (rockpro64- rm68200.patch attached)

- Compile and put the resulting rk3399-rockpro64.dtb on the target system. The panel driver shall then get probed at next boot.

The kernel log shall contain following errors:

[   10.139957] dw-mipi-dsi-rockchip ff960000.mipi: failed to write
command FIFO
[   10.139988] [drm:rm68200_dcs_write_cmd.isra.4
[panel_raydium_rm68200]] *ERROR* MIPI DSI DCS write failed: -110
[   10.160972] dw-mipi-dsi-rockchip ff960000.mipi: failed to write
command FIFO
[   10.161000] [drm:rm68200_dcs_write_buf.isra.5
[panel_raydium_rm68200]] *ERROR* MIPI DSI DCS write buffer failed: -110
[   10.181929] dw-mipi-dsi-rockchip ff960000.mipi: failed to write
command FIFO
[   10.181953] [drm:rm68200_dcs_write_buf.isra.5
[panel_raydium_rm68200]] *ERROR* MIPI DSI DCS write buffer failed: -110
[   10.202923] dw-mipi-dsi-rockchip ff960000.mipi: failed to write
command FIFO
[   10.202947] [drm:rm68200_dcs_write_buf.isra.5
[panel_raydium_rm68200]] *ERROR* MIPI DSI DCS write buffer failed: -110
[   10.223064] dw-mipi-dsi-rockchip ff960000.mipi: failed to write
command FIFO
[   10.223094] [drm:rm68200_dcs_write_buf.isra.5
[panel_raydium_rm68200]] *ERROR* MIPI DSI DCS write buffer failed: -110
[   10.226104] zram1: detected capacity change from 0 to 52428800
[   10.244027] dw-mipi-dsi-rockchip ff960000.mipi: failed to write
command FIFO
[   10.244073] [drm:rm68200_dcs_write_buf.isra.5
[panel_raydium_rm68200]] *ERROR* MIPI DSI DCS write buffer failed: -110
[   10.265024] dw-mipi-dsi-rockchip ff960000.mipi: failed to write
command FIFO
[   10.265064] [drm:rm68200_dcs_write_buf.isra.5
[panel_raydium_rm68200]] *ERROR* MIPI DSI DCS write buffer failed: -110
[   10.285711] dw-mipi-dsi-rockchip ff960000.mipi: failed to write
command FIFO
[   10.285746] [drm:rm68200_dcs_write_buf.isra.5
[panel_raydium_rm68200]] *ERROR* MIPI DSI DCS write buffer failed: -110
[   10.305926] dw-mipi-dsi-rockchip ff960000.mipi: failed to write
command FIFO
[   10.305955] [drm:rm68200_dcs_write_buf.isra.5
[panel_raydium_rm68200]] *ERROR* MIPI DSI DCS write buffer failed: -110
[   10.326996] dw-mipi-dsi-rockchip ff960000.mipi: failed to write
command FIFO
[   10.327039] [drm:rm68200_dcs_write_buf.isra.5
[panel_raydium_rm68200]] *ERROR* MIPI DSI DCS write buffer failed: -110
[   10.348030] dw-mipi-dsi-rockchip ff960000.mipi: failed to write
command FIFO
[   10.348074] [drm:rm68200_dcs_write_buf.isra.5
[panel_raydium_rm68200]] *ERROR* MIPI DSI DCS write buffer failed: -110

It's remarkable that if to pull the module panel-rm682000 out and then back in, there are no errors mentioned. I can for sure say that those commands become effective - I start seeing colourful stripes on the display after. That is, if I would send the correct command set to the panel, then it would bring up just fine. the panel, then it would bring up just fine.