Re: [PATCH 1/8] drm/display: hdmi: Add common TMDS character rate constants

[Javier Martinez Canillas]

Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxxxxxxxx> writes:

Hello Dmitry,

> On Tue, May 19, 2026 at 04:46:57PM +0200, Javier Martinez Canillas wrote:
>> Several DRM drivers already define their own constants for minimum and
>> maximum TMDS character rates.
>> 
>> By defining common rate constants in a shared header, drivers can just use
>> them instead of having driver local define macros or use magic numbers.
>> 
>> The values defined in the <drm/display/drm_hdmi_helper.h> header correspond
>> to maximum TMDS character rates defined by each HDMI specification version:
>> 
>>   - DRM_HDMI_TMDS_CHAR_RATE_MIN:    25 MHz (minimum for all versions)
>>   - DRM_HDMI_TMDS_CHAR_RATE_MAX_1_0: 165 MHz (HDMI 1.0 maximum)
>>   - DRM_HDMI_TMDS_CHAR_RATE_MAX_1_3: 340 MHz (HDMI 1.3 maximum)
>>   - DRM_HDMI_TMDS_CHAR_RATE_MAX_2_0: 600 MHz (HDMI 2.0 maximum)
>
> These values are also used by the HDMI PHY drivers. Would it make sense
> to define them in <linux/hdmi.h> instead?
>

Yes, I think you are correct.

In fact I spotted more HDMI PHY drivers that could also use these defined
constants but just included the most obvious ones in this patch series.

-- 
Best regards,

Javier Martinez Canillas
Core Platforms
Red Hat