Messages in this thread | | | Subject | Re: [PATCH 13/15] mtd: nand: samsung: retrieve ECC requirements from extended ID | From | Valdis.Kletnieks@vt ... | Date | Mon, 30 May 2016 16:56:09 -0400 |
| |
On Mon, 30 May 2016 09:44:46 +0200, Boris Brezillon said: > Hi Valdis,
> Actually, that was my first reaction [1], but the more I think about it > the more I realize it's a non-issue. > AFAICT, there's no full-id entries for Samsung NANDs in the nand_ids > table, so this either means there's no real users of Samsung MLCs or > NAND controller drivers connecting to those chips don't care about the > ->ecc_{step_ds,strength_ds} fields.
I'm mostly, though not totally convinced (not having looked closely at the existing code). There's still a possible issue with the distinction between:
A) "driver never references the variable" and
B) driver check if it's zero, and acts like it doesn't care if it is, but if it's non-zero, it goes ahead and uses it, with possible hilarity ensuing if the value is wrong.
Should be pretty easy for somebody who knows the code better than I to rule out case B fairly quickly...
> I agree that the solution is not perfect, but I'd prefer seeing the > NAND detection code iteratively improved than rejecting everything > until we're 100% sure that all cases are correctly handled (which might > never happen since NAND vendors introduce new NAND ID scheme if they > need to). > > BTW, do you have Samsung datasheets describing a different NAND ID > format, or is it purely hypothetical?
Mostly hypothetical. I've just seen too many patches that assume "all chips from vendor XYZ do *this*" that were not at all corrrect.
[unhandled content-type:application/pgp-signature] | |