Re: [PATCH v8 05/18] drm/bridge: Move legacy bridge driver out of imx directory for multi-platform use

[Damon Ding <damon.ding@rock-chips.com>]

Hi Luca,

On 1/31/2026 8:33 PM, Luca Ceresoli wrote:
> Hello Damon, Dmitry,
> 
> On Wed Dec 17, 2025 at 10:33 AM CET, Damon Ding wrote:
>> As suggested by Dmitry, the DRM legacy bridge driver can be pulled
>> out of imx/ subdir for multi-platform use. The driver is also renamed
>> to make it more generic and suitable for platforms other than i.MX.
>>
>> Signed-off-by: Damon Ding <damon.ding@rock-chips.com>
>> Suggested-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
>> Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
>>
>> ---
>>
>> Changes in v7:
>> - Rename legacy-bridge to of-display-mode-bridge.
>> - Remove unnecessary API drm_bridge_is_legacy().
> 
> ...
> 
>> --- a/drivers/gpu/drm/bridge/Kconfig
>> +++ b/drivers/gpu/drm/bridge/Kconfig
>> @@ -244,6 +244,16 @@ config DRM_NXP_PTN3460
>>   	help
>>   	  NXP PTN3460 eDP-LVDS bridge chip driver.
>>
>> +config DRM_OF_DISPLAY_MODE_BRIDGE
>> +	tristate
>> +	depends on DRM_BRIDGE && OF
>> +	help
>> +	  This is a DRM bridge implementation that uses of_get_drm_display_mode
>> +	  to acquire display mode.
>> +
>> +	  Newer designs should not use this bridge and should use proper panel
>> +	  driver instead.
> 
> "Newer designs should not use this bridge", but in patch 8 you are
> introducing a new use ot devm_drm_of_display_mode_bridge(). Shouldn't you
> instead "use proper panel driver instead" in patch 8?
> 
> Can you point to the conversation where the converstaion where Dmitry
> suggested this change? Maybe it already contains the answer to my
> qustion. Also adding a link to that conversation in the commit message
> woule be useful.
> 

First of all, thanks for your reviews on this patch series.

link: 
https://lore.kernel.org/all/xwenycscalzdlpuxytorbiyvej3k7pv3lhxwtadilxq65ipwsv@x5rxm53w5e22/

I think it may be a misleading issue caused by directly copying the 
previous Kconfig description. Now that the new 
devm_drm_of_display_mode_bridge() helper has been added, drivers using 
the panel-bridge framework can rely on it to maintain compatibility with 
legacy display mode parsing.

It would be better to update the comment as follows:

This is a DRM bridge implementation that uses of_get_drm_display_mode to 
acquire display mode.

It exists for compatibility with legacy display mode parsing, in order 
to conform to the panel-bridge framework.

Best regards,
Damon