On 04/08/2013 03:55 PM, Guennadi Liakhovetski wrote:
> On Mon, 8 Apr 2013, Sylwester Nawrocki wrote:
>> On 04/08/2013 01:07 PM, Guennadi Liakhovetski wrote:
[...]
>>> +static struct v4l2_async_subdev *v4l2_async_belongs(struct v4l2_async_notifier *notifier,
>>> + struct v4l2_async_subdev_list *asdl)
>>> +{
>>> + struct v4l2_async_subdev *asd = NULL;
>>> + bool (*match)(struct device *,
>>> + struct v4l2_async_hw_device *);
>>> +
>>> + list_for_each_entry (asd, ¬ifier->waiting, list) {
>>> + struct v4l2_async_hw_device *hw = &asd->hw;
>>> + switch (hw->bus_type) {
>>> + case V4L2_ASYNC_BUS_SPECIAL:
>>> + match = hw->match.special.match;
>>> + if (!match)
>>> + /* Match always */
>>> + return asd;
>>> + break;
>>> + case V4L2_ASYNC_BUS_PLATFORM:
>>> + match = match_platform;
>>> + break;
>>> + case V4L2_ASYNC_BUS_I2C:
>>> + match = match_i2c;
>>> + break;
>>> + default:
>>> + /* Oops */
>>> + match = NULL;
>>> + dev_err(notifier->v4l2_dev ? notifier->v4l2_dev->dev : NULL,
>>> + "Invalid bus-type %u on %p\n", hw->bus_type, asd);
>>> + }
>>> +
>>> + if (match && match(asdl->dev, hw))
>>> + break;
>>
>> Since we maintain various lists of sub-devices, couldn't we match them e.g. by
>> name instead ? What would be preventing this ?
>
> Do you have a specific case where your proposal would work, whereas mine
> wouldn't? This can be changed at any time, we can leave it until there's a
> real use-case, for which this implementation wouldn't work.
No, don't have any specific case in mind. Just was wondering if we don't
happen to be over-engineering things a bit. And yes, this seems something
that could be changed later if required.
>> And additionally provide an API to override the matching method?
>
> Override - that's what the "SPECIAL" (CUSTOM) is for.
Yes, I wanted to emphasize the idea to have a possibility for custom subdev
matching was good.
Regards,
Sylwester
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