Hi Lars, > Considering that there seems to be a common pattern here where the caller > only wants to know if the device exists, but is not really interested in the > device itself, how about adding a helper function for this?
It was my first thought when I opened this thread. But now I'm convinced that device_for_each_child() is the best choice (maybe I'm wrong). device_for_each_child() allow you to perform an operation of each child of a device: look for a specific child, do something on every children, retrieve a specific group of children, etc. I think that an helper for this case will be a perfect duplication of device_for_each_child() with a different name and comment (borrowed from device_find_child()). Maybe, a macro to assign a different name to this function: /* * [...] * The callback should return 0 if the device doesn't match and non-zero * if it does * [...] */ #define device_has_child(parent, data, match) device_for_each_child(parent, data, match) But, is it useful? It can be a suggestion to developers to prefer device_for_each_child() instead of device_find_child() when (s)he is interested only about the child existence. So, (s)he does not need to put_device(). But I think that is not a strong argumentation, and later in time someone will propose his own special use of device_for_each_child(). I think that device_for_each_child() is generic enough to cover this problem. -- Federico Vaga -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
