[PATCH v3 0/3] drm/rockchip: Add driver for the new DSI2 controller

[Daniel Semkowicz]

Hello Heiko,

On 03.12.24 21:54, Heiko Stuebner wrote:
> This series adds a bridge and glue driver for the DSI2 controller found
> in the rk3588 soc from Rockchip, that is based on a Synopsis IP block.
> 
> As the manual states:
> The Display Serial Interface 2 (DSI-2) is part of a group of communication
> protocols defined by the MIPI Alliance. The MIPI DSI-2 Host Controller is
> a digital core that implements all protocol functions defined in the
> MIPI DSI-2 Specification.
> 
> 
> While the driver structure is very similar to the previous DSI controller,
> the programming model of the core is quite different, with a completely
> new register set.
> 
> Another notable difference is that the phy interface is variable now too
> in its width and some other settings.
> 

I did more tests with different LVDS displays. I tested following
configurations with DSI/LVDS bridge:
- 1024x600 at 60.01
- 1024x768 at 60.02
- 1280x800 at 60.07
- 1366x768 at 60.06

All of them worked without issues, except 1366x768.
With this resolution, video is blurry, and offset incorrectly
to the left. There are also repeating errors on the console:

  rockchip-drm display-subsystem: [drm] *ERROR* POST_BUF_EMPTY irq err at vp3

In correct operation with other resolutions, there is no error.
I am not sure if this is a problem in your series or rather in VOP2
driver.

I tried to track down the problem, and it seems to be a generic issue
when horizontal line width is not divisible by 4.
Lowering line width to 1364px fixes the issue, but of course I have two
vertical lines of black pixels on the right.
I also made some tests with 720x1280 DSI display. Lowering horizontal
line to 718px shows the same problem. With 720px and 716px it works
correctly.

Kind regards
Daniel