diff options
Diffstat (limited to 'drivers/mtd/spi/spi_flash.c')
| -rw-r--r-- | drivers/mtd/spi/spi_flash.c | 22 |
1 files changed, 18 insertions, 4 deletions
diff --git a/drivers/mtd/spi/spi_flash.c b/drivers/mtd/spi/spi_flash.c index 0034a28d5f..34f68881ed 100644 --- a/drivers/mtd/spi/spi_flash.c +++ b/drivers/mtd/spi/spi_flash.c @@ -947,11 +947,25 @@ int spi_flash_scan(struct spi_flash *flash) if (IS_ERR_OR_NULL(info)) return -ENOENT; - /* Flash powers up read-only, so clear BP# bits */ + /* + * Flash powers up read-only, so clear BP# bits. + * + * Note on some flash (like Macronix), QE (quad enable) bit is in the + * same status register as BP# bits, and we need preserve its original + * value during a reboot cycle as this is required by some platforms + * (like Intel ICH SPI controller working under descriptor mode). + */ if (JEDEC_MFR(info) == SPI_FLASH_CFI_MFR_ATMEL || - JEDEC_MFR(info) == SPI_FLASH_CFI_MFR_MACRONIX || - JEDEC_MFR(info) == SPI_FLASH_CFI_MFR_SST) - write_sr(flash, 0); + (JEDEC_MFR(info) == SPI_FLASH_CFI_MFR_SST) || + (JEDEC_MFR(info) == SPI_FLASH_CFI_MFR_MACRONIX)) { + u8 sr = 0; + + if (JEDEC_MFR(info) == SPI_FLASH_CFI_MFR_MACRONIX) { + read_sr(flash, &sr); + sr &= STATUS_QEB_MXIC; + } + write_sr(flash, sr); + } flash->name = info->name; flash->memory_map = spi->memory_map; |