Messages in this thread |  | | From | <> | Subject | Re: [PATCH v2 1/3] UBI: Do not zero out EC and VID on ECC-ed NOR flashes | Date | Sat, 28 Nov 2020 10:58:02 +0000 |
| |
On 11/18/20 8:24 PM, Pratyush Yadav wrote: > EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe > > For NOR flashes EC and VID are zeroed out before an erase is issued to > make sure UBI does not mistakenly treat the PEB as used and associate it > with an LEB. > > But on some flashes, like the Cypress Semper S28 SPI NOR flash family, > multi-pass page programming is not allowed on the default ECC scheme. > This means zeroing out these magic numbers will result in the flash > throwing a page programming error. > > Do not zero out EC and VID for such flashes. A writesize > 1 is an > indication of an ECC-ed flash. > > Signed-off-by: Pratyush Yadav <p.yadav@ti.com> > --- > > Notes: > Changes in v2: > > - Use mtd->writesize to check if multi-pass programming can be done > instead of using MTD_NO_MULTI_PASS_WRITE. > - Remove the assertion that a NOR flash most have writesize of 1. > > drivers/mtd/ubi/build.c | 4 +--- > drivers/mtd/ubi/io.c | 9 ++++++++- > 2 files changed, 9 insertions(+), 4 deletions(-) > > diff --git a/drivers/mtd/ubi/build.c b/drivers/mtd/ubi/build.c > index e85b04e9716b..25fd7816b1f4 100644 > --- a/drivers/mtd/ubi/build.c > +++ b/drivers/mtd/ubi/build.c > @@ -628,10 +628,8 @@ static int io_init(struct ubi_device *ubi, int max_beb_per1024) > ubi->bad_peb_limit = get_bad_peb_limit(ubi, max_beb_per1024); > } > > - if (ubi->mtd->type == MTD_NORFLASH) { > - ubi_assert(ubi->mtd->writesize == 1); > + if (ubi->mtd->type == MTD_NORFLASH) > ubi->nor_flash = 1; > - } > > ubi->min_io_size = ubi->mtd->writesize; > ubi->hdrs_min_io_size = ubi->mtd->writesize >> ubi->mtd->subpage_sft; > diff --git a/drivers/mtd/ubi/io.c b/drivers/mtd/ubi/io.c > index 14d890b00d2c..2f3312c31e51 100644 > --- a/drivers/mtd/ubi/io.c > +++ b/drivers/mtd/ubi/io.c > @@ -535,7 +535,14 @@ int ubi_io_sync_erase(struct ubi_device *ubi, int pnum, int torture) > return -EROFS; > } > > - if (ubi->nor_flash) { > + /* > + * If the flash is ECC-ed then we have to erase the ECC block before we > + * can write to it. But the write is in preparation to an erase in the > + * first place. This means we cannot zero out EC and VID before the > + * erase and we just have to hope the flash starts erasing from the > + * start of the page. > + */ > + if (ubi->nor_flash && ubi->mtd->writesize == 1) {
Are there any SPI NORs with ECC block size of 4 bytes? Should we call nor_erase_prepare() in this case?
Anyway, there's none in SPI NOR as of now, so:
Reviewed-by: Tudor Ambarus <tudor.ambarus@microchip.com>
> err = nor_erase_prepare(ubi, pnum); > if (err) > return err; > -- > 2.28.0 >
|  |