At Thu, 19 Mar 2015 14:42:40 +0000, Mark Brown wrote:
On Thu, Mar 19, 2015 at 03:37:12PM +0100, Takashi Iwai wrote:
The uniqueness of item name is also needed for input jack. There is no check as of now, and input drivers allow multiple items with the very same name string, but user-space can't distinguish them.
The theory is that this is handled by the fact that the userspace ABI includes a reference to the struct device and therefore a chain showing where the thing is attached; anything registering two different jacks with the same name attached to the same device probably qualifies as broken.
So this implicitly assumes the name uniqueness. For HD-audio, this was a problem because we need to generate jack names dynamically; for example, there are laptops with two headphones, and we assigned indices in such a case.
Takashi