Re: [PATCH 2/8] drm/mxsfb/lcdif: don't unnecessarily loop over ports

Luca Ceresoli
2026-03-27T11:10:48Z

Hello Liu,

thanks for the careful and timely review of this series!

On Thu Mar 26, 2026 at 7:59 AM CET, Liu Ying wrote:
> Hi Luca,
>
> On Fri, Mar 20, 2026 at 11:46:13AM +0100, Luca Ceresoli wrote:
>> According to the bindings [0] there can be only one port. The in-tree board
>> device trees also don't contain multiple ports (searched thos matching
>
> s/thos/those/
>
>> 'fsl,imx(23|28|6sx|8mp|93)-lcdif').
>>
>> Avoid an unnecessary loop around multipltle ports. This allows to greatly
>
> s/multipltle/multiple/
>
>> simplify the code.
>>
>> [0] Documentation/devicetree/bindings/display/fsl,lcdif.yaml
>>
>> Signed-off-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
>>
>> ---
>>
>> Viewing this patch with '--ignore-all-space' is recommended
>> ---
>> drivers/gpu/drm/mxsfb/lcdif_drv.c | 77 ++++++++++++++-------------------------
>> 1 file changed, 27 insertions(+), 50 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/mxsfb/lcdif_drv.c b/drivers/gpu/drm/mxsfb/lcdif_drv.c
>> index 756ca96373c8..83e134c04882 100644
>> --- a/drivers/gpu/drm/mxsfb/lcdif_drv.c
>> +++ b/drivers/gpu/drm/mxsfb/lcdif_drv.c
>> @@ -48,61 +48,38 @@ static const struct drm_encoder_funcs lcdif_encoder_funcs = {
>> static int lcdif_attach_bridge(struct lcdif_drm_private *lcdif)
>> {
>> struct device *dev = lcdif->drm->dev;
>> - struct device_node *ep;
>> + struct drm_encoder *encoder;
>> struct drm_bridge *bridge;
>> int ret;
>>
>> - for_each_endpoint_of_node(dev->of_node, ep) {
>
> The single i.MX93 LCDIF may connect with a DPI/LVDS/MIPI DSI encoder.
> Each encoder maps to an endpoint in a port, hence 3 endpoints in all.
> See lcdif node in imx91_93_common.dtsi and imx93.dtsi in linux-next/master.

My bad, I hadn't realized that, perhaps because it was not yet on
drm-misc-next when I did my research. Thanks for noticing.

Luckily the fundamental reason for which I thought I needed this changed
has vanished even before I sent this v1, so I'll just drop this patch and
adapt the follwing ones as needed.

Luca

--
Luca Ceresoli, Bootlin
Embedded Linux and Kernel engineering