mtd: spi-nor: fix Spansion regressions (aliased with Winbond)

Spansion and Winbond have occasionally used the same manufacturer ID,
and they don't support the same features. Particularly, writing SR=0
seems to break read access for Spansion's s25fl064k. Unfortunately, we
don't currently have a way to differentiate these Spansion and Winbond
parts, so rather than regressing support for these Spansion flash, let's
drop the new Winbond lock/unlock support for now. We can try to address
Winbond support during the next release cycle.

Original discussion:

http://patchwork.ozlabs.org/patch/549173/
http://patchwork.ozlabs.org/patch/553683/

Fixes: 357ca38d47 ("mtd: spi-nor: support lock/unlock/is_locked for Winbond")
Fixes: c6fc2171b2 ("mtd: spi-nor: disable protection for Winbond flash at startup")
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Reported-by: Felix Fietkau <nbd@openwrt.org>
Cc: Felix Fietkau <nbd@openwrt.org>
This commit is contained in:
Brian Norris 2015-12-15 10:48:20 -08:00
parent 472b444eef
commit 67b9bcd369
2 changed files with 3 additions and 5 deletions

View file

@ -1200,8 +1200,7 @@ int spi_nor_scan(struct spi_nor *nor, const char *name, enum read_mode mode)
if (JEDEC_MFR(info) == SNOR_MFR_ATMEL ||
JEDEC_MFR(info) == SNOR_MFR_INTEL ||
JEDEC_MFR(info) == SNOR_MFR_SST ||
JEDEC_MFR(info) == SNOR_MFR_WINBOND) {
JEDEC_MFR(info) == SNOR_MFR_SST) {
write_enable(nor);
write_sr(nor, 0);
}
@ -1217,8 +1216,7 @@ int spi_nor_scan(struct spi_nor *nor, const char *name, enum read_mode mode)
mtd->_read = spi_nor_read;
/* NOR protection support for STmicro/Micron chips and similar */
if (JEDEC_MFR(info) == SNOR_MFR_MICRON ||
JEDEC_MFR(info) == SNOR_MFR_WINBOND) {
if (JEDEC_MFR(info) == SNOR_MFR_MICRON) {
nor->flash_lock = stm_lock;
nor->flash_unlock = stm_unlock;
nor->flash_is_locked = stm_is_locked;

View file

@ -25,7 +25,7 @@
#define SNOR_MFR_MACRONIX CFI_MFR_MACRONIX
#define SNOR_MFR_SPANSION CFI_MFR_AMD
#define SNOR_MFR_SST CFI_MFR_SST
#define SNOR_MFR_WINBOND 0xef
#define SNOR_MFR_WINBOND 0xef /* Also used by some Spansion */
/*
* Note on opcode nomenclature: some opcodes have a format like