Re: [PATCH v4 7/9] drm-bridge: it66121: Use fwnode API to acquire device properties

[Sui Jingfeng]

Hi,


On 2024/4/23 04:06, Dmitry Baryshkov wrote:
> > +
> >   static int it66121_probe(struct i2c_client *client)
> >   {
> >   	u32 revision_id, vendor_ids[2] = { 0 }, device_ids[2] = { 0 };
> > -	struct device_node *ep;
> >   	int ret;
> >   	struct it66121_ctx *ctx;
> >   	struct device *dev = &client->dev;
> > +	struct fwnode_handle *fwnode = dev_fwnode(dev);
> >   
> >   	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
> >   		dev_err(dev, "I2C check functionality failed.\n");
> > @@ -1520,29 +1542,20 @@ static int it66121_probe(struct i2c_client *client)
> >   	if (!ctx)
> >   		return -ENOMEM;
> >   
> > -	ep = of_graph_get_endpoint_by_regs(dev->of_node, 0, 0);
> > -	if (!ep)
> > -		return -EINVAL;
> > -
> >   	ctx->dev = dev;
> >   	ctx->client = client;
> >   	ctx->info = i2c_get_match_data(client);
> >   
> > -	of_property_read_u32(ep, "bus-width", &ctx->bus_width);
> > -	of_node_put(ep);
> > -
> > -	if (ctx->bus_width != 12 && ctx->bus_width != 24)
> > -		return -EINVAL;
> > -
> > -	ep = of_graph_get_remote_node(dev->of_node, 1, -1);
> > -	if (!ep) {
> > -		dev_err(ctx->dev, "The endpoint is unconnected\n");
> > -		return -EINVAL;
> > -	}
> > +	ret = it66121_read_bus_width(fwnode, &ctx->bus_width);
> > +	if (ret)
> > +		return ret;
> >   
> > -	ctx->next_bridge = of_drm_find_bridge(ep);
> > -	of_node_put(ep);
> > -	if (!ctx->next_bridge) {
> > +	ctx->next_bridge = drm_bridge_find_next_bridge_by_fwnode(fwnode, 1);
> > +	if (IS_ERR(ctx->next_bridge)) {
> > +		ret = PTR_ERR(ctx->next_bridge);
> > +		dev_err(dev, "Error in founding the next bridge: %d\n", ret);
> > +		return ret;
> return dev_err_probe(dev, ret, "msg"), if your function doesn't do this.
> If it does, just return ret.


My drm_bridge_find_next_bridge_by_fwnode() function won't return -EPROBE_DEFER
this is known for sure. As a//prior(priori) knowledge. Calling the dev_err_probe()
just introduce extra overhead. It is useless to use dev_err_probe() here.
 

--
Best regards,
Sui