[PATCH 09/12] cfi_flash: do not reset flash when probe fails

Jean-Christophe PLAGNIOL-VILLARD plagnioj at jcrosoft.com
Fri Nov 26 14:52:38 EST 2010

The CFI flash driver starts at flash_init() which calls down into
flash_get_size().  This starts by calling flash_detect_cfi().  If said
function fails, flash_get_size() finishes by attempting to reset the
flash.  Unfortunately, it does this with an info->portwidth set to 0x10
which filters down into flash_make_cmd() and that happily smashes the
stack by sticking info->portwidth bytes into a cfiword_t variable that
lives on the stack.  On a 64bit system you probably won't notice, but
killing the last 8 bytes on a 32bit system usually leads to a corrupt
return address.  Which is what happens on a Blackfin system.

based on U-Boot

Signed-off-by: Mike Frysinger <vapier at gentoo.org>
Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj at jcrosoft.com>
 drivers/nor/cfi_flash.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/drivers/nor/cfi_flash.c b/drivers/nor/cfi_flash.c
index 041fb92..a7df3b4 100644
--- a/drivers/nor/cfi_flash.c
+++ b/drivers/nor/cfi_flash.c
@@ -494,9 +494,9 @@ static ulong flash_get_size (struct flash_info *info, ulong base)
 		if ((info->interface == FLASH_CFI_X8X16) && (info->chipwidth == FLASH_CFI_BY8)) {
 			info->portwidth >>= 1;	/* XXX - Need to test on x8/x16 in parallel. */
+		flash_write_cmd (info, 0, 0, info->cmd_reset);
-	flash_write_cmd (info, 0, 0, info->cmd_reset);
 	return info->size;

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