Re: [PATCH v11 2/2] drm/bridge: Add Lontium LT9611C(EX/UXD) MIPI DSI to HDMI driver

[Luca Ceresoli]

Hello Mohit,

On Mon Aug 31, 2026 at 8:38 PM CEST, Mohit Dsor wrote:

[...]

>> > +#include <drm/drm_of.h>
>>
>> Unused include?
> Using this header for of_drm_get_bridge_by_endpoint

of_drm_get_bridge_by_endpoint() is declared in drm_bridge.h.

>> > +static enum drm_mode_status
>> > +lt9611c_hdmi_tmds_char_rate_valid(const struct drm_bridge *bridge,
>>                      ^^^^
>> Out of curiosity, what does "char" means here?
> "char" = character — TMDS (Transition Minimized Differential Signaling) transmits data using 8b/10b encoding, where each
>   encoded 10-bit symbol is called a "character". The TMDS character rate is the number of these symbols transmitted per second
>   per lane, which equals the TMDS clock frequency.

Ah, OK, thanks for the explanation.

>> Also, I _think_ lt9611c_regulator_init() could just
>> devm_regulator_bulk_get_enable() to do both things at once, but I'm not
>> sure that would be compatible with PM. If it's safe it would simplify the
>> code quite a lot, and also allow using devm_drm_bridge_add() below, making
>> the remove function almost empty.
> regulator_bulk_disable/enable are called in suspend/resume and in remove — so devm_regulator_bulk_get_enable is not suitable
>   here

OK, I was not sure about that, thanks for checking.

Luca

--
Luca Ceresoli, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com