[flashrom-gerrit] [M] Change in flashrom[main]: libflashrom: Update the API for progress callback

[Peter Marheine (Code Review)]

Attention is currently required from: Anastasia Klimchuk, Richard Hughes, Sergii Dmytruk.

Peter Marheine has posted comments on this change by Anastasia Klimchuk. ( https://review.coreboot.org/c/flashrom/+/86031?usp=email )

Change subject: libflashrom: Update the API for progress callback
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Patch Set 9:

(1 comment)

File include/flash.h:

https://review.coreboot.org/c/flashrom/+/86031/comment/206931c0_9fd7b81d?usp... :
PS8, Line 624: 	flashrom_progress_callback_v2 *progress_callback;
             : 	struct flashrom_progress progress_state;
             : 	struct stage_progress stage_progress[FLASHROM_PROGRESS_NR];
             : 	/* deprecated, do not use */
             : 	flashrom_progress_callback *deprecated_progress_callback;
             : 	struct flashrom_progress *deprecated_progress_state;
> There is one important detail in current implementation which I think won't work with the union. […]

That makes sense, but I think that means the old function is currently inconsistent in its behavior because it's sensitive to the order in which callbacks are initialized: doing the old one first will register both, but the new one first will only register the new one. It's plausible that a library user might mix the old and new APIs on a single flash context, where it would be confusing to be sensitive to initialization order.

I think either mixing them should be forbidden, or `flashrom_set_progress_callback` needs to always work.