Hi Liu,
On Fri, 24 Aug 2018 22:41:41 +0800
Liu Xiang <liu.xia...@zte.com.cn> wrote:
> The is25lp256 supports 4-byte opcodes and quad output.
> In is25lp256, the DWORD1 of JEDEC Basic Flash Parameter Header
> is 0xfff920e5. So the DWORD1[18:17] Address Bytes bits are 0b00,
> means that 3-Byte only addressing. Now this limits nor->addr_width
> to 3 and makes it inpossible to access the address above 16MB.
> I think the size of flash is the most important judgement for
> nor->addr_width. Once the size is larger than 16MB, nor->addr_width
> must be 4. This can avoid the bad situation that manufacturer sets
> incorrect value of register.
Please split this patch:
- Add 4B_OPCODES flag to is25lp256
- Rework the ->addr_width selection logic (more about that below).
>
> Signed-off-by: Liu Xiang <liu.xia...@zte.com.cn>
> ---
> drivers/mtd/spi-nor/spi-nor.c | 14 +++++++-------
> 1 file changed, 7 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c
> index d9c368c..0203b09 100644
> --- a/drivers/mtd/spi-nor/spi-nor.c
> +++ b/drivers/mtd/spi-nor/spi-nor.c
> @@ -1065,7 +1065,7 @@ static int spi_nor_is_locked(struct mtd_info *mtd,
> loff_t ofs, uint64_t len)
> { "is25lp128", INFO(0x9d6018, 0, 64 * 1024, 256,
> SECT_4K | SPI_NOR_DUAL_READ) },
> { "is25lp256", INFO(0x9d6019, 0, 64 * 1024, 512,
> - SECT_4K | SPI_NOR_DUAL_READ) },
> + SECT_4K | SPI_NOR_DUAL_READ | SPI_NOR_QUAD_READ |
> SPI_NOR_4B_OPCODES) },
> { "is25wp032", INFO(0x9d7016, 0, 64 * 1024, 64,
> SECT_4K | SPI_NOR_DUAL_READ | SPI_NOR_QUAD_READ) },
> { "is25wp064", INFO(0x9d7017, 0, 64 * 1024, 128,
> @@ -2926,16 +2926,16 @@ int spi_nor_scan(struct spi_nor *nor, const char
> *name,
> if (ret)
> return ret;
>
> - if (nor->addr_width) {
> - /* already configured from SFDP */
> - } else if (info->addr_width) {
> - nor->addr_width = info->addr_width;
> - } else if (mtd->size > 0x1000000) {
> + if (mtd->size > 0x1000000) {
> /* enable 4-byte addressing if the device exceeds 16MiB */
> nor->addr_width = 4;
> if (JEDEC_MFR(info) == SNOR_MFR_SPANSION ||
> - info->flags & SPI_NOR_4B_OPCODES)
> + info->flags & SPI_NOR_4B_OPCODES)
> spi_nor_set_4byte_opcodes(nor, info);
> + } else if (nor->addr_width) {
> + /* already configured from SFDP */
> + } else if (info->addr_width) {
> + nor->addr_width = info->addr_width;
> } else {
> nor->addr_width = 3;
> }
We'd rather return an error and warn users when nor->addr_width does not
match the device size than fix this mismatch silently.
Regards,
Boris
