Hi all, as you know, NAND flash can be programmed a limited number of times before it reaches end of life, the number of times varies with the NAND technology used, among other things. As far as I can tell from the simplified SD-spec, there is no way of asking the card about how many program/erase cycles it can handle, or how many p/e cycles are left before reaching EOL. Right? So, if one should want to give the user some kind of early warning that it's time to change SD-cards, is there a way? Also, when a card has reached EOL, is there a way of telling this condition apart from all other error conditions that may arise? As you know, depending on the quality of the card and controller, read timeouts, write timeouts, lockups etc may occur but can usually be fixed with a power cycle. I'm thinking of collecting simple statistics from for instance card/block.c and exposing it via an ioctl or sysfs. The statistics can be gathered and processed by some user space process which can determine if the user needs to be alerted. The statistics can be, for instance: * Writes/reads that timeout, but succeed after a retry * Writes/reads that timeout and never succeeds * Different kinds of errors in the card status * Anything else? Perhaps it's not possible to detect worn out cards this way, but at least it could point out and warn about crappy cards? Any thoughts about this? Kind regards, Johan -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
