> >Hi Bean, > >On Mon, 3 Apr 2017 11:31:05 +0000 >"Bean Huo (beanhuo)" <beanhuo@xxxxxxxxxx> wrote: > >> Hi, Boris and Thomas >> >> >> >> >> Ok, but I recommend that 70s should be the first choice on this >> >> single solution, it doesn't need to read twice to detect its bitflips count. >> > >> >That's exactly why we need to differentiate the 2 chips. >> >> Sorry for later this response. >> Below is the pseudo codes about how to differentiate these 2 series >> parallel NAND with on-die ECC: >> >> if (NAND == SLC ) { // on-die ECC only exists in SLC //check device ID >> byte 4 >> if ((ID.byte4 & 0x02) == 0x02) {// internal ECC level ==10b > >So here the MT29F1G08ABADAWP datasheet says 0x2 <=> 4bit/512bytes ECC. > >> if (ID.byte4 & 0x80) {//on-Die ECC enabled > >Did you read my last reply? >Thomas discovered that ID[4].bit7 is actually reflecting the ECC engine state (1 if >the engine is enabled, 0 if it's disabled), not whether the NAND supports on-die >ECC or not, so no this test is not reliable. > >> if (ONFI.byte112 == 4) >> 60s SLC NAND with on-die ECC >> else if (ONFI.byte112 == 8) >> 70s SLC NAND with on-die ECC > >This is completely fucked up! Now the ONFI param page says the NAND requires >8bits/512bytes, while the ID bytes advertised an on-die ECC providing >4bits/512bytes correctability. >So either your algorithm is wrong, or the ID and ONFI param page are contracting >(not sure what solution I'd prefer...). > >> else >> Doesn't support on-die ECC > >Sorry to say that, but I find it worrisome that even someone from Micron is not >able to get it right. > Sorry, would you please specify which one is wrong or confuse you? >I think we'll stick to the model name to detect whether on-die ECC is supported. > You want one solution that can clearly differentiate two serial SLC NAND, but NAND ONFI table and device Id are always changing. It is easy to draw a perfect solution to do that. OK, if you like maintain a huge/ugly table in MTD, please do that. >Regards, > >Boris -- 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