Re: [PATCH v4 0/3] drm/tidss: Add OLDI bridge support

Sverdlin, Alexander
2025-03-19T18:00:25Z

Thank you for the patches, Aradhya!

On Sun, 2024-11-24 at 20:06 +0530, Aradhya Bhatia wrote:
> Regardless, I'd appreciate it if somebody can test it, and report back if they
> observe any issues.

I've tried to test the patchset with necessary pre-requisites and DT additions
with a single channel LVDS pannel and while I'm not successful yet, I've also noticed
the following warning:

tidss 30200000.dss: vp0: Clock rate 24285714 differs over 5% from requested 37000000

even though later the clock seems to be correctly set up:

$ cat /sys/kernel/debug/clk/clk_summary

enable prepare protect duty hardware connection
clock count count count rate accuracy phase cycle enable consumer id
---------------------------------------------------------------------------------------------------------------------------------------------
clk:186:6 1 1 0 250000000 0 0 50000 Y 30200000.dss fck
deviceless no_connection_id
clk:186:4 0 0 0 0 0 0 50000 Y deviceless no_connection_id
clk:186:3 0 0 0 170000000 0 0 50000 Y deviceless no_connection_id
clk:186:2 0 0 0 170000000 0 0 50000 Y 30200000.dss vp2
deviceless no_connection_id
clk:186:0 1 1 0 259090909 0 0 50000 Y oldi@0 serial
deviceless no_connection_id
clock-divider-oldi 1 1 0 37012987 0 0 50000 Y 30200000.dss vp1

Looks like "clock-divider-oldi" doesn't propagate clk_set_rate() to the parent,
but the parent is being set later independently?

--
Alexander Sverdlin
Siemens AG