Re: [PATCH v13 2/8] mtd: rawnand: rockchip: NFC drivers for RK3308, RK2928 and others

[Miquel Raynal <miquel.raynal@bootlin.com>]

Hi Johan, Yifeng

Johan Jonker <jbx6244@gmail.com> wrote on Mon, 2 Nov 2020 13:57:56
+0100:

> Hi Yifeng,
> 
> Don't poke with "ecc->bytes" ones it is set in rk_nfc_ecc_init(). It
> will not be noted by the MTD frame work or userspace. I think there's
> currently no way to let the user know that a different ECC must be used.
> Neither can the user set ECC on the fly.
> 
> Example R/W flow:
> 
>         nand_select_target()
> 	chip->ecc.write_page_raw()
> 	chip->ecc.write_page()
> 
> [..]
> 
> 	chip->ecc.read_page_raw()
> 	chip->ecc.read_page()
>         nand_deselect_target()
> 
> A write/read with:
> 
> rk_nfc_read_page_hwecc()
> rk_nfc_write_page_hwecc()
> 
> or
> 
> rk_nfc_read_page_raw()
> rk_nfc_write_page_raw()
> 
> must end up with the same result. If we can't archive that, then we
> shouldn't offer RAW mode to the user for now. If Miquel agrees you
> should just get the driver ready now without these 2 functions and round
> things up.

What about just not supporting the BootROM area if it was marked
"reserved" by the BRom in the DT?

Raw accessors is really a nice and basic feature that I would like to
have in every new driver.

Thanks,
Miquèl