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authorMichael Schwingen <michael@schwingen.org>2008-02-18 23:16:35 +0100
committerStefan Roese <sr@denx.de>2008-02-21 17:12:19 +0100
commit1ba639da5604a64b3ed884a2cbb1c5414a9fa728 (patch)
tree67fc8f460e38a920281717647949a69fdd9956c2 /drivers
parent928d1d77f8623c120d8763e20e1ca58df9c5c4c6 (diff)
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CFI: Do not use uninitialized cmd_reset
Do not use uninitialized cmd_reset; issue both AMD and Intel reset commands instead From a short test, it looks like AMD-style flash roms treat *any* unknown command write as a reset, at least when in CFI Query mode, so issuing the Intel reset command to AMD-style flashs seems safe (from the small sample I have), plus the 3-cycle magic sequence should kick the state machine into the right state even without a reset command. Since the AMD-style flashs require the unlock sequence for real operation, I chose to try the AMD reset command first, so that Intel flashs do no see an invalid command prior to the CFI query. I have tested the patch on AM29LV320-style flashs from Fujitsu and Macronix, plus Intel StrataFlash. Signed-off-by: Michael Schwingen <michael@schwingen.org> Signed-off-by: Stefan Roese <sr@denx.de>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/mtd/cfi_flash.c7
1 files changed, 6 insertions, 1 deletions
diff --git a/drivers/mtd/cfi_flash.c b/drivers/mtd/cfi_flash.c
index eb509f5..439c950 100644
--- a/drivers/mtd/cfi_flash.c
+++ b/drivers/mtd/cfi_flash.c
@@ -1538,7 +1538,12 @@ static int __flash_detect_cfi (flash_info_t * info, struct cfi_qry *qry)
{
int cfi_offset;
- flash_write_cmd (info, 0, 0, info->cmd_reset);
+ /* We do not yet know what kind of commandset to use, so we issue
+ the reset command in both Intel and AMD variants, in the hope
+ that AMD flash roms ignore the Intel command. */
+ flash_write_cmd (info, 0, 0, AMD_CMD_RESET);
+ flash_write_cmd (info, 0, 0, FLASH_CMD_RESET);
+
for (cfi_offset=0;
cfi_offset < sizeof(flash_offset_cfi) / sizeof(uint);
cfi_offset++) {