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

-----Original Message----- From: Michael Trimarchi michael@amarulasolutions.com Sent: Wednesday, April 27, 2022 12:50 AM To: Han Xu han.xu@nxp.com; U-Boot-Denx u-boot@lists.denx.de Cc: Ye Li ye.li@nxp.com; Stefano Babic sbabic@denx.de; Miquel Raynal miquel.raynal@bootlin.com; Fabio Estevam festevam@denx.de; Dario Binacchi dario.binacchi@amarulasolutions.com; Sean Anderson sean.anderson@seco.com; linux-kernel@amarulasolutions.com; Jagan Teki jagan@amarulasolutions.com; Ariel D'Alessandro ariel.dalessandro@collabora.com; Fabio Estevam festevam@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.

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@nxp.com Cc: Fabio Estevam festevam@gmail.com Signed-off-by: Michael Trimarchi michael@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->erasesize / 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