Re: [PATCH v5 1/5] counter: Internalize sysfs interface code

David Lechner
2020-10-15T01:40:13Z

On 9/26/20 9:18 PM, William Breathitt Gray wrote:
> +static ssize_t counter_comp_u8_store(struct device *dev,
> + struct device_attribute *attr,
> + const char *buf, size_t len)
> +{
> + const struct counter_attribute *const a = to_counter_attribute(attr);
> + struct counter_device *const counter = dev_get_drvdata(dev);
> + struct counter_count *const count = a->parent;
> + struct counter_synapse *const synapse = a->comp.priv;
> + const struct counter_available *const avail = a->comp.priv;
> + int err;
> + bool bool_data;
> + u8 data;
> +
> + switch (a->comp.type) {
> + case COUNTER_COMP_BOOL:
> + err = kstrtobool(buf, &bool_data);
> + data = bool_data;
> + break;
> + case COUNTER_COMP_FUNCTION:
> + err = find_in_string_array(&data, count->functions_list,
> + count->num_functions, buf,
> + counter_function_str);
> + break;
> + case COUNTER_COMP_SYNAPSE_ACTION:
> + err = find_in_string_array(&data, synapse->actions_list,
> + synapse->num_actions, buf,
> + counter_synapse_action_str);
> + break;
> + case COUNTER_COMP_ENUM:
> + err = __sysfs_match_string(avail->strs, avail->num_items, buf);
> + data = err;
> + break;
> + case COUNTER_COMP_COUNT_MODE:
> + err = find_in_string_array(&data, avail->enums,
> + avail->num_items, buf,
> + counter_count_mode_str);
> + break;
> + default:
> + err = kstrtou8(buf, 0, &data);
> + break;
> + }

In this function, return values are not always errors. So it would make
sense to call the err variable ret instead and check for ret < 0 below.

Setting enums to a value with index > 0 fails currently because of this.

> + if (err)
> + return err;
> +
> + switch (a->scope) {
> + case COUNTER_SCOPE_DEVICE:
> + err = a->comp.device_u8_write(counter, data);
> + break;
> + case COUNTER_SCOPE_SIGNAL:
> + err = a->comp.signal_u8_write(counter, a->parent, data);
> + break;
> + case COUNTER_SCOPE_COUNT:
> + if (a->comp.type == COUNTER_COMP_SYNAPSE_ACTION)
> + err = a->comp.action_write(counter, count, synapse,
> + data);
> + else
> + err = a->comp.count_u8_write(counter, count, data);
> + break;
> + }
> + if (err)
> + return err;
> +
> + return len;
> +}