Hi Martin, On Sun, 3 Jun 2018 13:31:35 +0200, Martin Kaiser <mar...@kaiser.cx> wrote:
> The v21 version of the NAND flash controller contains a Spare Area Size > Register (SPAS) at offset 0x10. Its setting defaults to the maximum > spare area size of 218 bytes. The size that is set in this register is > used by the controller when it calculates the ECC bytes internally in > hardware. > > Usually, this register is updated from settings in the IIM fuses when > the system is booting from nand flash. For other boot media, however, s/nand/NAND > the SPAS register remains at the default setting, which may not work for > the particular flash chip on the board. The same goes for flash chips > whose configuration cannot be set in the IIM fuses (e.g. chips with 2k > sector size and 128 bytes spare area size can't be configured in the IIM > fuses on imx25 systems). > > Set the SPAS register explicitly during the preset operation. Derive the > register value from mtd->oobsize that was detected during probe by > decoding the flash chip's ID bytes. > > While at it, rename the define for the spare area register's offset to > NFC_V21_RSLTSPARE_AREA. The register at offset 0x10 on v1 controllers is > different from the register on v21 controllers. > > Signed-off-by: Martin Kaiser <mar...@kaiser.cx> > Cc: sta...@vger.kernel.org > --- > drivers/mtd/nand/raw/mxc_nand.c | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) > > diff --git a/drivers/mtd/nand/raw/mxc_nand.c b/drivers/mtd/nand/raw/mxc_nand.c > index 45786e7..c2f8572 100644 > --- a/drivers/mtd/nand/raw/mxc_nand.c > +++ b/drivers/mtd/nand/raw/mxc_nand.c > @@ -48,7 +48,7 @@ > #define NFC_V1_V2_CONFIG (host->regs + 0x0a) > #define NFC_V1_V2_ECC_STATUS_RESULT (host->regs + 0x0c) > #define NFC_V1_V2_RSLTMAIN_AREA (host->regs + 0x0e) > -#define NFC_V1_V2_RSLTSPARE_AREA (host->regs + 0x10) > +#define NFC_V21_RSLTSPARE_AREA (host->regs + 0x10) > #define NFC_V1_V2_WRPROT (host->regs + 0x12) > #define NFC_V1_UNLOCKSTART_BLKADDR (host->regs + 0x14) > #define NFC_V1_UNLOCKEND_BLKADDR (host->regs + 0x16) > @@ -1274,6 +1274,9 @@ static void preset_v2(struct mtd_info *mtd) > writew(config1, NFC_V1_V2_CONFIG1); > /* preset operation */ > > + /* spare area size in 16bit words */ I thought I understood the problem with your commit message but then I don't get this comment. What's the link between 16-bit buses? Is this preset valid for both 8 and 16-bit bus width? > + writew(mtd->oobsize >> 1, NFC_V21_RSLTSPARE_AREA); > + If this is for dividing per two oobsize value, I would really prefer a '/ 2' and let the compiler optimize things. Unless the spec is explicit about some shifting of course. > /* Unlock the internal RAM Buffer */ > writew(0x2, NFC_V1_V2_CONFIG); > Thanks for fixing this. Regards, Miquèl
