AnsweredAssumed Answered

MIPI DSI read register returns protocol error

Question asked by Linh Nguyen on Jan 1, 2020
Latest reply on Jan 4, 2020 by Linh Nguyen

Happy new year everybody,


I'm bringing up 5" LCD using MIPI DSI on iMX8MQ board, now the backlight is up, but nothing was displayed on LCD.

Then I'm trying to read some MIPI DSI registers from display driver, but every reads return RX ACK and error ("SoT Error |  SoT Sync Error" or "False Control Error"), I followed reference here Linux source code: drivers/gpu/drm/panel/panel-samsung-s6e8aa0.c (v4.19.91) - Bootlin .

debug message shows:

[ 2.182172] nwl-mipi-dsi 30a00000.mipi_dsi_bridge: [drm:nwl_dsi_irq_handler] *ERROR* [52] DSI error report: 0x40
[ 2.182187] LINH sharp nt35596_dump_regs(): DBG get brightness ret -71, val 65535

The error printed from line nwl-dsi.c\bridge\drm\gpu\drivers - linux-imx - i.MX Linux kernel  .

Is there anybody experienced this kind of error and what can be the cause?

Thank you.