rte_devargs_parse

[Dmitry Kozlyuk <dkozlyuk@nvidia.com>]

Hello,

/**
 * Parse a device string.
 *
 * Verify that a bus is capable of handling the device passed
 * in argument. Store which bus will handle the device, its name
 * and the eventual device parameters.
 *
 * [SNIP]
 *
 * @param da
 *   The devargs structure holding the device information.
 *
 * [SNIP]
 */
int rte_devargs_parse(struct rte_devargs *da, const char *dev);

It is unclear from this description that "da" is not only filled,
but also used as an input, and if it is not initialized
or at least zero-filled, the function will crash.
"Holding the device information" is not helpful,
because it doesn't say it's a pre- or post-condition,
or what must be filled on input (if everything, why parse at all?).
In test_devargs.c, test_valid_devargs_cases() zero-fills "da",
but test_invalid_devargs() does not, which is probably wrong.

Is the function intended to work this way?
What use case is covered by calling it with initialized "da"?