> On 11/05/2011 03:24 AM, Marek Vasut wrote: > > There is a problem reported that the NAND_NO_SUBPAGE_WRITE, set by some > > drivers, is silently ignored by NAND core. This causes UBI to > > malfunction on these drivers, because UBI tries to use subpage writes. > > Hi Marek, > > > This was discussed already with no conclusion, see thread: > > Message-Id: <1302372335-30232-6-git-send-email-sba...@denx.de> > > Right, there was some discussion also comparing what it is done on the > Linux Kernel. There is a discrepancy for the usage of the > NAND_NO_SUBPAGE_WRITE, because it belongs to the chip options, but in > this case (and in the patch I submitted) it is used as "controller" > option. Same case here.
Yes sure, but the controller driver sets it as a chip option as there's no "controller" option field and I don't want to introduce new definition consuming one bit in the top half of chip option. > > > The bug was recently retriggered by Veli-Pekka Peltola, causing him > > trouble with UBI on the MX28 CPU: > > Message-ID: <4eb3e4ea.9080...@bluegiga.com> > > > > drivers/mtd/nand/nand_base.c | 11 +++++++++++ > > 1 files changed, 11 insertions(+), 0 deletions(-) > > > > diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c > > index 6aac6a2..7ecd5a3 100644 > > --- a/drivers/mtd/nand/nand_base.c > > +++ b/drivers/mtd/nand/nand_base.c > > @@ -2548,6 +2548,7 @@ static const struct nand_flash_dev > > *nand_get_flash_type(struct mtd_info *mtd, > > > > { > > > > int ret, maf_idx; > > int tmp_id, tmp_manf; > > > > + int no_subpage = 0; > > > > /* Select the device */ > > chip->select_chip(mtd, 0); > > > > @@ -2612,10 +2613,20 @@ static const struct nand_flash_dev > > *nand_get_flash_type(struct mtd_info *mtd, > > > > if (!ret) > > > > nand_flash_detect_non_onfi(mtd, chip, type, &busw); > > > > + /* > > + * If the controller is incapable of subpage writes, force no subpage > > + * writes. This has to be done here, otherwise UBI will complain. > > + */ > > + if (chip->options & NAND_NO_SUBPAGE_WRITE) > > + no_subpage = 1; > > + > > The patch does not convince me. This relies only if the SUBPAGE_WRITE is > supported by the chip, and this is half problem. What happens if we have > a SLC (that generally supports subpage mode) connected to a controller > that does not support it ? NAND_NO_SUBPAGE_WRITE is not set, but the > controller can't manage it. > I think your patch fix only a particular case, and it is not general > enough. No, the controller must set NAND_NO_SUBPAGE_WRITE as a chip option in its driver to force it so it should work for both cases. Cheers _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot