Re: [PATCH v2] hwmon: corsair-cpro: Change to HID driver

From: Guenter Roeck
Date: Wed Jul 15 2020 - 15:50:04 EST


On 7/15/20 12:12 PM, Marius Zachmann wrote:
> On 15.07.20 at 17:35:08 CEST, Guenter Roeck wrote
>> On 7/15/20 8:14 AM, Marius Zachmann wrote:
>>> This changes corsair-cpro to a hid driver using hid reports.
>>>
>>> Signed-off-by: Marius Zachmann <mail@xxxxxxxxxxxxxxxxx>
>>>
>>> ---
>>
> ...
>>> -module_usb_driver(ccp_driver);
>>> +static int __init ccp_init(void)
>>> +{
>>> + return hid_register_driver(&ccp_driver);
>>> +}
>>> +
>>> +static void __exit ccp_exit(void)
>>> +{
>>> + hid_unregister_driver(&ccp_driver);
>>> +}
>>> +
>>> +/* make sure it is loaded after hid */
>>> +late_initcall(ccp_init);
>>> +module_exit(ccp_exit);
>>
>> Sorry for not noticing before, but can you use module_hid_driver() ?
>> That seems to work for other hid drivers.
>>
>> Thanks,
>> Guenter
>>
>
> When using module_hid_driver() and compiling the driver as built-in
> the driver init function will get called before hid and fail registering
> the driver. late_initcall forces it to be loaded after hid.
>

That seems odd. Why does no other hid driver have that problem ?
Your argument is pretty much that module_hid_driver() would not work,
which seems unlikely.

Thanks,
Guenter