On 20.11.2012 16:59, Peter Korsgaard wrote: >>>>>> "Daniel" == Daniel Mack <zonque@xxxxxxxxx> writes: > > Hi, > > >>>> In omap2 driver NAND_ECC_HW ecc mode supports 3 ecc layout > >>>> OMAP_ECC_HAMMING_CODE_HW_ROMCODE > >>>> OMAP_ECC_BCH4_CODE_HW > >>>> OMAP_ECC_BCH8_CODE_HW > >>>> > >>>> So selection of ecc layout data should come from DT not ecc mode. > >>> > >>> Ok, I see. I would still like to set them by string rather than magic > >>> numbers that map to enum entries. Valid values would be "none", "hw", > >>> "hw-romcode", "bch4" and "bch8". Are you ok with that? > >> > >> Ok, that's nice. Better use ecc_opt instead of ecc_mode. > > Daniel> I did some more extensive tests that include reading the same > Daniel> nand pages from both U-Boot and the kernel with BCH8 ECC, and > Daniel> it turns out that -> is_elm_used needs to be set in the pdata > Daniel> in order to make this work. > > So what you're saying is that the choice of ELM or not is not just an > optimization, it really changes the ECC layout? Perhaps it should be > treated as a seperate layout (E.G. bch8-elm) then? That is what I experienced, yes. The kernel was unable to parse NAND pages that were written from U-Boot with bch8 hardware mode when the elm module was not active. Maybe someone from TI can explain that? Giving it a dedicated name would also solve the problem with the extra DT property. I'll wait until this is decided before I resend a new set that also fixes the issue with the errornousely forgotten Documentation file. Thanks, Daniel -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
