On 12/17/2011 08:35 AM, Artem Bityutskiy wrote: > On Mon, 2011-12-12 at 15:30 -0600, Scott Wood wrote: >> On 12/12/2011 03:19 PM, Artem Bityutskiy wrote: >>> On Mon, 2011-12-12 at 15:15 -0600, Scott Wood wrote: >>>> NAND chips come from the factory with bad blocks marked at a certain >>>> offset into each page. This offset is normally in the OOB area, but >>>> since we change the layout from "4k data, 128 byte oob" to "2k data, 64 >>>> byte oob, 2k data, 64 byte oob" the marker is no longer in the oob. On >>>> first use we need to migrate the markers so that they are still in the oob. >>> >>> Ah, I see, thanks. Are you planning to implement in-kernel migration or >>> use a user-space tool? >> >> That's the kind of answer I was hoping to get from Shuo. :-) >> >> Most likely is a firmware-based tool, but I'd like there to be some way >> for the tool to mark that this has happened, so that the Linux driver >> can refuse to do non-raw accesses to a chip that isn't marked as having >> been migrated (or at least yell loudly in the log). >> >> Speaking of raw accesses, these are currently broken in the eLBC >> driver... we need some way for the generic layer to tell us what kind of >> access it is before the transaction starts, not once it wants to read >> out the buffer (unless we add more hacks to delay the start of a read >> transaction until first buffer access...). We'd be better off with a >> high-level "read page/write page" function that does the whole thing >> (not just buffer access, but command issuance as well). > > It looks like currently you can re-define chip->read_page, so I guess > you should rework MTD and make chip->write_page re-definable?
Unless something has changed very recently, there is no chip->read_page or chip->write_page. There is chip->ecc.read_page and chip->ecc.write_page, but they are too low-level. What we'd need to replace is a portion of nand_do_read_ops()/nand_do_write_ops(). -Scott _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
