Re: [PATCH v2 00/15] mtd: nand: allow vendor specific detection/initialization

From: Richard Weinberger
Date: Sat Jun 18 2016 - 18:09:51 EST




Am 08.06.2016 um 15:00 schrieb Boris Brezillon:
> Hello,
>
> This patch series is a step forward in supporting vendor-specific
> functionalities.
> This series is mainly moving vendor-specific initialization or
> detection code out of the core, but also introduces an infrastructure
> allowing support for vendor-specific features.
>
> While those features might seem useless to most users, some of them are
> actually required on modern MLC/TLC NANDs (this is the case of read-retry
> support, which AFAICT has not been standardized by the JEDEC consortium).
>
> Now, let's detail what's inside this patch-set.
>
> Patches 1 to 4 are simple reworks simplifying auto-detection function
> prototypes, and clarifying their purpose.
>
> Patch 5 is introducing the vendor-specific initialization
> infrastructure.
>
> Patch 6 is removing the MTD_NAND_IDS Kconfig option to avoid creating
> a nand_ids.ko module when MTD_NAND is enabled as a module. This prevents
> a future cross-dependency between nand.ko where all vendor specific
> code will rely and nand_ids.ko which will reference vendor-specific ops
> in its manufacturer table, which in turn is referenced by the core code
> linked in nand.ko.
>
> Patches 7 to 12 are moving vendor-specific code into their respective
> nand_<vendor>.c files.
>
> Patch 13 is taking a patch proposed by Hans and adding support for ECC
> requirements extraction from the samsung extended IDs. It seems to apply
> to all Samsung MLCs, but even if it's not the case, the detection code
> should be improved to support the new formats.
>
> Patch 14 is adding support for advanced NAND ID decoding to the Hynix
> driver (OOB size, ECC and scrambling requirements extraction). Again
> this detection code might be incomplete, but I'd like people to extend
> it if required rather than adding new full-id entries in the nand_ids
> table.
>
> And finally, patch 15 is showing how useful this vendor-specific stuff
> can be by implementing read-retry support for Hynix 1x nm MLCs. And
> trust me, you don't want to try using such a NAND without read-retry
> support ;).
>
> As always, I'm open to any suggestion to improve this vendor-specific
> infrastructure, so please review the code :).

Series looks good to me. :-)

BTW: I wonder whether this work can also be used to support
Micron On-Die-ECC and Toshiba BENAND in a proper way.

Thanks,
//richard