On Mon, 18 Jul 2016 10:39:18 +0200 Hector Palacios <hector.palacios@xxxxxxxx> wrote: > nand_do_write_ops() determines if it is writing a partial page with the > formula: > part_pagewr = (column || writelen < (mtd->writesize - 1)) > > When 'writelen' is exactly 1 byte less than the NAND page size the formula > equates to zero, so the code doesn't process it as a partial write, > although it should. > As a consequence the function remains in the while(1) loop with 'writelen' > becoming 0xffffffff and iterating endlessly. > > The bug may not be easy to reproduce in Linux since user space tools > usually force the padding or round-up the write size to a page-size > multiple. > This was discovered in U-Boot where the issue can be reproduced by > writing any size that is 1 byte less than a page-size multiple. > For example, on a NAND with 2K page (0x800): > => nand erase.part <partition> > => nand write $loadaddr <partition> 7ff > > Signed-off-by: Hector Palacios <hector.palacios@xxxxxxxx> Acked-by: Boris Brezillon <boris.brezillon@xxxxxxxxxxxxxxxxxx> Brian, can you take this patch in your tree. As usual, I'm unsure whether we should Cc stable or not, but we should at least add Fixes: 66507c7bc8895 ("mtd: nand: Add support to use nand_base poi databuf as bounce buffer") > --- > drivers/mtd/nand/nand_base.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c > index 0b0dc29d2af7..77533f7f2429 100644 > --- a/drivers/mtd/nand/nand_base.c > +++ b/drivers/mtd/nand/nand_base.c > @@ -2610,7 +2610,7 @@ static int nand_do_write_ops(struct mtd_info *mtd, loff_t to, > int cached = writelen > bytes && page != blockmask; > uint8_t *wbuf = buf; > int use_bufpoi; > - int part_pagewr = (column || writelen < (mtd->writesize - 1)); > + int part_pagewr = (column || writelen < mtd->writesize); > > if (part_pagewr) > use_bufpoi = 1; -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html