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

Sui Jingfeng
2024-04-27T13:12:06Z

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