Messages in this thread | | | Date | Wed, 25 Aug 2021 17:31:14 +0200 | From | Miquel Raynal <> | Subject | Re: [PATCH v2] mtd: rawnand: xway: No hardcoded ECC engine, use device tree setting |
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> > > > > > > thank you for your response. > > > > > > > If I remove the nand-ecc-xxx properties in the device tree, the device with > > > > > > > the Toshiba NAND chip is working. However, the device with the Micron > > > > > > > NAND fails with NO ECC functions supplied; hardware ECC not possible, > > > > > > > seems to be at line 5367 or equivalent. > > > > > > > https://elixir.bootlin.com/linux/latest/source/drivers/mtd/nand/raw/nand_base.c#L5367 > > > > > > > > > > > > > > It looks like the micron nand driver supports on die only if its > > > > > > > specified int the > > > > > > > Device tree: > > > > > > > https://elixir.bootlin.com/linux/latest/source/drivers/mtd/nand/raw/nand_micron.c#L511 > > > > > > > The Micron NAND driver probably needs to set the ECC type to ON DIE if the > > > > > > > variable ondie contains the supported attribute?! > > > > > > > > > > > > You're right but I don't see any easy upstream-able solution here. > > > > > > Changing the behavior in the Xway driver would certainly break users, > > > > > > changing the behavior in the Micron driver would certainly break even > > > > > > more users. The root cause being an absence of proper description (the > > > > > > integration changed). Honestly I feel stuck, maybe you can try to > > > > > > register your device, if it fails, change the integration in the driver > > > > > > (to an ondie ecc engine) then retry? > > > > > > > > > > > > Thanks, > > > > > > Miquèl > > > > > > > > > > Do you think adding something like below at the following location > > > > > https://elixir.bootlin.com/linux/latest/source/drivers/mtd/nand/raw/xway_nand.c#L223 > > > > > would be upstreamable (with or without device tree property?)? > > > > > > > > > > err = nand_scan(&data->chip, 1); > > > > > if (err /* && of_property_read_bool(np, "lantiq,retry-on-die") */) { > > > > > data->chip.ecc.engine_type = NAND_ECC_ENGINE_TYPE_ON_DIE; > > > > > err = nand_scan(&data->chip, 1); > > > > > if (err) return err; > > > > > } > > > > > > > > > > It still throws the kernel warning on first try, but the second try then works. > > > > > > > > Can you please remind me what is xway/lantiq/your setup/how public it > > > > is/who's using this driver? > > > > > > > > Thanks, > > > > Miquèl > > > > > > Its for Openwrt, I would like to add support for 3 more devices > > > AVM fritzbox 3490/5490 and 7490. They all have varying NAND chips. > > > I have initially created a PR to have my initial patch tested: > > > https://github.com/openwrt/openwrt/pull/4426 > > > There is already one device supported which has two DTBs one for > > > Micron and one for non Micron (3370), but its not very straight forward. > > > Without having this issue solved, flashing those devices would be > > > possibly having issues depending on NAND chip or the awkward > > > workaround of flashing one image and if it does not boot, boot the > > > other one. Without self soldered serial console, it would not very > > > easy to figure out the NAND manufacturer. > > > The AVM stock firmware is old kernel and does not use device > > > tree for NAND, they just query all possible manufacturers and set > > > up NAND based on manufacturer query. > > > > But in this case can't you check the 'root' compatible against certain > > values and and some kind of quirk in the ->attach() hook to update the > > ECC engine to the right one? > > > > Thanks, > > Miquèl > > maybe I wrote the wrong thing, but what do you mean with root compatible. > The controller is always NAND xway and I think there are 4 different > NAND chip types. But the stock firmware just queries the NAND > manufacturer name, not a date or type/model of the devices. E.g. 7490 can > have Micron or Macronix NAND, but querying the Micron id or Macronix > id requires a change to the xway driver? > Do you mean something like in the first patch do query the manufacturer > but just for all the 4? > > Thanks, Daniel.
You were talking about new boards, if, on each of these boards, you know what is the NAND chip, you could retrieve the root compatible (by root I mean the one at the root of the tree / { } in the DT) and depending on it change the ECC engine that must be used from the driver itself.
Thanks, Miquèl
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