Hi Brian, On 2015-09-29 13:57, Brian Norris wrote: > Pushed this patch to l2-mtd.git, as it looks pretty much good. Although, > I'd like raw read support... > > On Wed, Sep 02, 2015 at 06:06:34PM -0700, Stefan Agner wrote: >> This adds hardware ECC support using the BCH encoder in the NFC IP. >> The ECC encoder supports up to 32-bit correction by using 60 error >> correction bytes. There is no sub-page ECC step, ECC is calculated >> always accross the whole page (up to 2k pages). >> >> Limitations: >> - HW ECC: Only 2K page with 64+ OOB. >> - HW ECC: Only 24 and 32-bit error correction implemented. >> >> Raw writes have been tested using the generic nand_write_page_raw >> implementation. However, raw reads are currently not possible >> because the controller need to know whether we are going to use >> the ECC mode already at NAND_CMD_READ0 command time. At this point >> we do not have the information whether it is a raw read or a >> regular read at driver level... > > Hmm, can you get this in ecc.read_page_raw()? Even just a read_page_raw implementation doesn't help. The controller requires the ECC to be configured at command issue time, and the driver issues the command in the cmdfunc callback. The function nand_do_read_ops calls cmdfunc before ecc.read_page_raw... I could just bail out in the NAND_CMD_READ0 case, and execute the command from within the ecc.read_page_raw callback function. A bit hacky, but that would work. For that case, it would be nicer if cmdfunc somehow provides the information that a raw read is requested, we would have that information in nand_do_read_ops. However, that would need an extension of the cmdfunc interface... Also, not sure how that should look like. -- Stefan -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
