Commit 28fa65e6 authored Feb 12, 2014 by Brian Norris

mtd: nand: fix off-by-one read retry mode counting



A flash may support N read retry voltage threshold modes, numbered 0
through N-1 (where mode 0 represents the initial state). However,
nand_do_read_ops() tries to use mode 0 through N.

This off-by-one error shows up, for instance, when using nanddump, and
we have cycled through available modes:

    nand: setting READ RETRY mode 0
    nand: setting READ RETRY mode 1
    nand: setting READ RETRY mode 2
    nand: setting READ RETRY mode 3
    nand: setting READ RETRY mode 4
    nand: setting READ RETRY mode 5
    nand: setting READ RETRY mode 6
    nand: setting READ RETRY mode 7
    nand: setting READ RETRY mode 8
    libmtd: error!: cannot read 8192 bytes from mtd0 (eraseblock 20, offset 0)
            error 22 (Invalid argument)
    nanddump: error!: mtd_read

Tested on Micron MT29F64G08CBCBBH1, with 8 retry modes.

Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Acked-by: Huang Shijie <b32955@freescale.com>

parent b28a960c

drivers/mtd/nand/nand_base.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -1584,7 +1584,7 @@ read_retry:
		}

		if (mtd->ecc_stats.failed - ecc_failures) {
		if (retry_mode + 1 <= chip->read_retries) {
		if (retry_mode + 1 < chip->read_retries) {
		retry_mode++;
		ret = nand_setup_read_retry(mtd,
		retry_mode);