| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.7 26/69] mtd: spi-nor: fix wrong "fully unlocked" test | Date | Wed, 28 Sep 2016 11:05:08 +0200 |
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4.7-stable review patch. If anyone has any objections, please let me know.
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From: Brian Norris <computersforpeace@gmail.com>
commit 06586204714b7befec99e554c71687b0b40f351c upstream.
In stm_unlock(), the test to determine whether we've fully unlocked the flash checks for the lock length to be equal to the flash size. That is a typo/think-o -- the condition actually means the flash is completely *locked.* We should be using the inverse condition -- that the lock length is 0 (i.e., no protection).
The result of this bug is that we never actually turn off the Status Register Write Disable bit, even if the flash is completely unlocked. Now we can.
Fixes: 47b8edbf0d43 ("mtd: spi-nor: disallow further writes to SR if WP# is low") Reported-by: Giorgio <giorgio.nicole@arcor.de> Signed-off-by: Brian Norris <computersforpeace@gmail.com> Cc: Ezequiel Garcia <ezequiel@vanguardiasur.com.ar> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- drivers/mtd/spi-nor/spi-nor.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/drivers/mtd/spi-nor/spi-nor.c +++ b/drivers/mtd/spi-nor/spi-nor.c @@ -661,7 +661,7 @@ static int stm_unlock(struct spi_nor *no status_new = (status_old & ~mask & ~SR_TB) | val; /* Don't protect status register if we're fully unlocked */ - if (lock_len == mtd->size) + if (lock_len == 0) status_new &= ~SR_SRWD; if (!use_top)
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