[PATCH V2 2/4] mtd: nand: mxs_nand_spl: Fix bad block skipping

Han Xu han.xu at nxp.com
Mon May 2 23:32:15 CEST 2022


On 22/05/01 08:36AM, Michael Nazzareno Trimarchi wrote:
> Dear Han and Fabio
> 
> On Thu, Apr 28, 2022 at 7:01 AM Michael Nazzareno Trimarchi
> <michael at amarulasolutions.com> wrote:
> >
> > Hi
> >
> > On Thu, Apr 28, 2022 at 2:27 AM Han Xu <han.xu at nxp.com> wrote:
> > >
> > >
> > >
> > > > -----Original Message-----
> > > > From: Michael Trimarchi <michael at amarulasolutions.com>
> > > > Sent: Wednesday, April 27, 2022 12:50 AM
> > > > To: Han Xu <han.xu at nxp.com>; U-Boot-Denx <u-boot at lists.denx.de>
> > > > Cc: Ye Li <ye.li at nxp.com>; Stefano Babic <sbabic at denx.de>; Miquel Raynal
> > > > <miquel.raynal at bootlin.com>; Fabio Estevam <festevam at denx.de>; Dario
> > > > Binacchi <dario.binacchi at amarulasolutions.com>; Sean Anderson
> > > > <sean.anderson at seco.com>; linux-kernel at amarulasolutions.com; Jagan Teki
> > > > <jagan at amarulasolutions.com>; Ariel D'Alessandro
> > > > <ariel.dalessandro at collabora.com>; Fabio Estevam <festevam at gmail.com>
> > > > Subject: [PATCH V2 2/4] mtd: nand: mxs_nand_spl: Fix bad block skipping
> > > >
> > > > The specific implementation was having bug. Those bugs are since the beginning
> > > > of the implementation. Some manufactures can receive this bug in their SPL code.
> > > > This bug start to be more visible on architecture that has complicated boot
> > > > process like imx8mn. Older version of uboot has the same problem only if the
> > > > bad block appear in correspoding of befine of u-boot image. In order to adjust
> > > > the function we scan from the first block. The logic is not changed to have a
> > > > simple way to fix without get regression.
> > > >
> > > > The problematic part of old code was in this part:
> > > >
> > > > while (is_badblock(mtd, offs, 1)) {
> > > >            page = page + nand_page_per_block;
> > > >           /* Check i we've reached the end of flash. */
> > > >           if (page >= mtd->size >> chip->page_shift) {
> > > >                       free(page_buf);
> > > >                       return -ENOMEM;
> > > >          }
> > > > }
> > > >
> > > > Even we fix it adding increment of the offset of one erase block size we don't fix
> > > > the problem, because the first erase block where the image start is not checked.
> > >
> > > Could you please describe more details about your test? Thanks.
> >
> > Suppose you have a badblock on 5 or 6. Let's start to have only 6
> > and you write uboot from 5 and let's the uboot be enough big to cover 5, 6, 7, 8
> >
> >
> > Case 1)
> > When you write the block 6 the code will skip it as bad during
> > programming. THe image of uboot (or flash.bin) will
> > be on 5 7 8 9, because the 6 is skipped. The while loop on spl will
> > read (from raw offset the 5) and then he will found the
> > bad block on next erase block in the while loop and will exists at the
> > end of the flash because the test
> > is done on the offset and not on the page that is not incremented
> >
> > Case 2)
> >
> > Now same example but let's suppose to have block 5 bad. So you write
> > your image and it will start
> > from a raw offset 5 but it will be written starting from 6. The spl
> > loader will fail because it will not skip
> > the first block and then will fail anyway to read the image. The patch
> > try to fix the above behavior
> >
> > Case 3) can be any combination
> >
> 
> Do I need to resend v3?
> 
> Michael

It's not about the v3. I need to discuss some details with ROM team but
unfortunately they are all in vacation till May 5th. I will respond after the
discussion.

> 
> > Michael
> >
> >
> >
> > >
> > > > The code was tested on an imx8mn where the boot rom api was not able to skip
> > > > it. Apart of that other architecure are using this code and all boards that has
> > > > nand as boot device can be affected
> > > >
> > > > Cc: Han Xu <han.xu at nxp.com>
> > > > Cc: Fabio Estevam <festevam at gmail.com>
> > > > Signed-off-by: Michael Trimarchi <michael at amarulasolutions.com>
> > > > ---
> > > > V1->V2:
> > > >       - Adjust the commit message
> > > >       - Add Cc Han Xu and Fabio
> > > >       - fix size >= 0 to > 0
> > > > ---
> > > >  drivers/mtd/nand/raw/mxs_nand_spl.c | 90 ++++++++++++++++-------------
> > > >  1 file changed, 49 insertions(+), 41 deletions(-)
> > > >
> > > > diff --git a/drivers/mtd/nand/raw/mxs_nand_spl.c
> > > > b/drivers/mtd/nand/raw/mxs_nand_spl.c
> > > > index 59a67ee414..2bfb181007 100644
> > > > --- a/drivers/mtd/nand/raw/mxs_nand_spl.c
> > > > +++ b/drivers/mtd/nand/raw/mxs_nand_spl.c
> > > > @@ -218,14 +218,14 @@ void nand_init(void)
> > > >       mxs_nand_setup_ecc(mtd);
> > > >  }
> > > >
> > > > -int nand_spl_load_image(uint32_t offs, unsigned int size, void *buf)
> > > > +int nand_spl_load_image(uint32_t offs, unsigned int size, void *dst)
> > > >  {
> > > > -     struct nand_chip *chip;
> > > > -     unsigned int page;
> > > > +     unsigned int sz;
> > > > +     unsigned int block, lastblock;
> > > > +     unsigned int page, page_offset;
> > > >       unsigned int nand_page_per_block;
> > > > -     unsigned int sz = 0;
> > > > +     struct nand_chip *chip;
> > > >       u8 *page_buf = NULL;
> > > > -     u32 page_off;
> > > >
> > > >       chip = mtd_to_nand(mtd);
> > > >       if (!chip->numchips)
> > > > @@ -235,47 +235,42 @@ int nand_spl_load_image(uint32_t offs, unsigned int
> > > > size, void *buf)
> > > >       if (!page_buf)
> > > >               return -ENOMEM;
> > > >
> > > > -     page = offs >> chip->page_shift;
> > > > -     page_off = offs & (mtd->writesize - 1);
> > > > +     /* offs has to be aligned to a page address! */
> > > > +     block = offs / mtd->erasesize;
> > > > +     lastblock = (offs + size - 1) / mtd->erasesize;
> > > > +     page = (offs % mtd->erasesize) / mtd->writesize;
> > > > +     page_offset = offs % mtd->writesize;
> > > >       nand_page_per_block = mtd->e
> > Copy Link
> > MA
> > Copy Link
> > NA
> > Copy Link
> > rasesize / mtd->writesize;
> > > >
> > > > -     debug("%s offset:0x%08x len:%d page:%x\n", __func__, offs, size, page);
> > > > -
> > > > -     while (size) {
> > > > -             if (mxs_read_page_ecc(mtd, page_buf, page) < 0)
> > > > -                     return -1;
> > > > -
> > > > -             if (size > (mtd->writesize - page_off))
> > > > -                     sz = (mtd->writesize - page_off);
> > > > -             else
> > > > -                     sz = size;
> > > > -
> > > > -             memcpy(buf, page_buf + page_off, sz);
> > > > -
> > > > -             offs += mtd->writesize;
> > > > -             page++;
> > > > -             buf += (mtd->writesize - page_off);
> > > > -             page_off = 0;
> > > > -             size -= sz;
> > > > -
> > > > -             /*
> > > > -              * Check if we have crossed a block boundary, and if so
> > > > -              * check for bad block.
> > > > -              */
> > > > -             if (!(page % nand_page_per_block)) {
> > > > -                     /*
> > > > -                      * Yes, new block. See if this block is good. If not,
> > > > -                      * loop until we find a good block.
> > > > -                      */
> > > > -                     while (is_badblock(mtd, offs, 1)) {
> > > > -                             page = page + nand_page_per_block;
> > > > -                             /* Check i we've reached the end of flash. */
> > > > -                             if (page >= mtd->size >> chip->page_shift) {
> > > > +     while (block <= lastblock && size > 0) {
> > > > +             if (!is_badblock(mtd, mtd->erasesize * block, 1)) {
> > > > +                     /* Skip bad blocks */
> > > > +                     while (page < nand_page_per_block) {
> > > > +                             int curr_page = nand_page_per_block * block +
> > > > page;
> > > > +
> > > > +                             if (mxs_read_page_ecc(mtd, page_buf, curr_page)
> > > > < 0) {
> > > >                                       free(page_buf);
> > > > -                                     return -ENOMEM;
> > > > +                                     return -EIO;
> > > >                               }
> > > > +
> > > > +                             if (size > (mtd->writesize - page_offset))
> > > > +                                     sz = (mtd->writesize - page_offset);
> > > > +                             else
> > > > +                                     sz = size;
> > > > +
> > > > +                             memcpy(dst, page_buf + page_offset, sz);
> > > > +                             dst += sz;
> > > > +                             size -= sz;
> > > > +                             page_offset = 0;
> > > > +                             page++;
> > > >                       }
> > > > +
> > > > +                     page = 0;
> > > > +             } else {
> > > > +                     lastblock++;
> > > >               }
> > > > +
> > > > +             block++;
> > > >       }
> > > >
> > > >       free(page_buf);
> > > > @@ -294,6 +289,19 @@ void nand_deselect(void)
> > > >
> > > >  u32 nand_spl_adjust_offset(u32 sector, u32 offs)  {
> > > > -     /* Handle the offset adjust in nand_spl_load_image,*/
> > > > +     unsigned int block, lastblock;
> > > > +
> > > > +     block = sector / mtd->erasesize;
> > > > +     lastblock = (sector + offs) / mtd->erasesize;
> > > > +
> > > > +     while (block <= lastblock) {
> > > > +             if (is_badblock(mtd, block * mtd->erasesize, 1)) {
> > > > +                     offs += mtd->erasesize;
> > > > +                     lastblock++;
> > > > +             }
> > > > +
> > > > +             block++;
> > > > +     }
> > > > +
> > > >       return offs;
> > > >  }
> > > > --
> > > > 2.25.1
> > >
> >
> >
> > --
> > Michael Nazzareno Trimarchi
> > Co-Founder & Chief Executive Officer
> > M. +39 347 913 2170
> > michael at amarulasolutions.com
> > __________________________________
> >
> > Amarula Solutions BV
> > Joop Geesinkweg 125, 1114 AB, Amsterdam, NL
> > T. +31 (0)85 111 9172
> > info at amarulasolutions.com
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> 
> 
> 
> -- 
> Michael Nazzareno Trimarchi
> Co-Founder & Chief Executive Officer
> M. +39 347 913 2170
> michael at amarulasolutions.com
> __________________________________
> 
> Amarula Solutions BV
> Joop Geesinkweg 125, 1114 AB, Amsterdam, NL
> T. +31 (0)85 111 9172
> info at amarulasolutions.com
> https://eur01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.amarulasolutions.com%2F&data=05%7C01%7Chan.xu%40nxp.com%7C81091e4443d745ce460708da2b3cec6a%7C686ea1d3bc2b4c6fa92cd99c5c301635%7C0%7C0%7C637869837927785927%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=I5jvEx5qmQLzO8QrQT9aMYttDPZhdvbGi0Z2lk77bio%3D&reserved=0


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