Re: [PATCH v5 3/3] drm/bridge: ti-sn65dsi83: Add reversed lvds lanes support

[Wojciech Dubowik <wojciech.dubowik@mt.com>]

On Fri, Jul 17, 2026 at 10:49:19PM +0200, Luca Ceresoli wrote:
> On Fri, 17 Jul 2026 13:50:01 +0200, Wojciech Dubowik <wojciech.dubowik@mt.com> wrote:

Hello Luca,

> 
> Hello,
> 
> >
> > diff --git a/drivers/gpu/drm/bridge/ti-sn65dsi83.c b/drivers/gpu/drm/bridge/ti-sn65dsi83.c
> > index f8a786953526..df44df2e872a 100644
> > --- a/drivers/gpu/drm/bridge/ti-sn65dsi83.c
> > +++ b/drivers/gpu/drm/bridge/ti-sn65dsi83.c
> > @@ -845,6 +863,19 @@ static int sn65dsi83_parse_lvds_endpoint(struct sn65dsi83 *ctx, int channel)
> >  	else
> >  		return -EINVAL;
> >  
> > +	ret_data = of_property_read_u32_array(endpoint, "data-lanes", data_lanes,
> > +			ARRAY_SIZE(data_lanes));
> > +	if (!ret_data) {
> > +		if (memcmp(data_lanes,
> > +				supported_data_lane_mapping[LANE_MAPPING_REVERSE],
> > +				ARRAY_SIZE(data_lanes)) == 0)
> 
> Did you have a look at this sashiko report? It seems valid:
>  | sashiko-bot@kernel.org <sashiko-bot@kernel.org>:
>  |
>  | [Severity: Medium]
>  | Does this code compare the entire array? memcmp() expects the length in
>  | bytes, but ARRAY_SIZE(data_lanes) evaluates to 4 (the number of elements).
>  |
>  | Because data_lanes is an array of u32, checking only 4 bytes means only
>  | the first element is compared. Should this be using sizeof(data_lanes)
>  | instead?
>  |
>  | via: https://patch.msgid.link/20260717115630.C58A61F000E9@smtp.kernel.org
> 
> > +			ctx->lvds_reverse_lanes_conf[channel] = true;
> > +		else if (memcmp(data_lanes,
> > +			   supported_data_lane_mapping[LANE_MAPPING_NORMAL],
> > +			   ARRAY_SIZE(data_lanes)) != 0)
> 

My stupid copy/paste error. I don't know how I have missed it. It has passed
my basic testing as it compares only firs lane. I will fix it in v6.

Regards,
Wojtek


> Same here.
> 
> Otherwise looks good.
> 
> Luca
> 
> -- 
> Luca Ceresoli, Bootlin
> Embedded Linux and Kernel engineering
> https://bootlin.com
>