Hi Jiri,
Thanks for your comments. I added comments in-lined.
Best regards,
Dennis
On 19.12.2016 10:54, Jiri Kosina wrote:
> Hi Dennis,
>
> thanks a lot for the patch.
>
> On Fri, 9 Dec 2016, Dennis Wassenberg wrote:
>
>> +int hid_lenovo_led_set(enum hid_lenovo_led_type led, bool on)
>> +{
>> + struct led_classdev *dev = NULL;
>> + struct lenovo_led_list_entry *entry;
>> +
>> + if (led >= HID_LENOVO_LED_MAX)
>> + return -EINVAL;
>> +
>> + hid_lenovo_initial_leds[led] = on ? LED_FULL : LED_OFF;
>> +
>> + list_for_each_entry(entry, &hid_lenovo_leds, list) {
>> + if (entry->type == led) {
>> + dev = entry->dev;
>> + break;
>> + }
>> + }
>
> How exactly is this synchronized against lenovo_remove_tpx1cover()?
>
In case of that the tpx1cover is disconnected it will be removed from hid_lenovo_leds list. That means not included at the hid_lenovo_leds list. In this case dev is still NULL and the function will return -ENODEV. The static array hid_lenovo_initial_leds is still set to store the current state of a LED type. This is used to set the LED appropriately if the tpx1cover is replugged.
Maybe I should add a mutex to protect the hid_lenovo_leds list operations in hid-lenovo.c to fix the case if a unplug occurred concurrently to setting an led?!
>> +
>> + if (!dev)
>> + return -ENODEV;
>> +
>> + if (!dev->brightness_set)
>> + return -ENODEV;
>> +
>> + dev->brightness_set(dev, on ? LED_FULL : LED_OFF);
>> +
>> + return 0;
>> +}
>> +EXPORT_SYMBOL_GPL(hid_lenovo_led_set);
>
> Does this really need to be exported to the whole universe? (I guess this
> will be further discussed in 4/4).
No, it is sufficient if thinkpad-helper can access it.
>
--
To unsubscribe from this list: send the line "unsubscribe linux-input" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
