Re: [RESEND PATCH v2] mtd: spi-nor: Fix address width on flash chips > 16MB

From: Pratyush Yadav
Date: Tue Oct 06 2020 - 11:18:24 EST


On 06/10/20 03:23PM, Bert Vermeulen wrote:
> If a flash chip has more than 16MB capacity but its BFPT reports
> BFPT_DWORD1_ADDRESS_BYTES_3_OR_4, the spi-nor framework defaults to 3.
>
> The check in spi_nor_set_addr_width() doesn't catch it because addr_width
> did get set. This fixes that check.
>
> Fixes: f9acd7fa80be ("mtd: spi-nor: sfdp: default to addr_width of 3 for configurable widths")
> Signed-off-by: Bert Vermeulen <bert@xxxxxxxx>
> Reviewed-by: Tudor Ambarus <tudor.ambarus@xxxxxxxxxxxxx>
> ---
> drivers/mtd/spi-nor/core.c | 8 +++++---
> 1 file changed, 5 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/mtd/spi-nor/core.c b/drivers/mtd/spi-nor/core.c
> index 0369d98b2d12..a2c35ad9645c 100644
> --- a/drivers/mtd/spi-nor/core.c
> +++ b/drivers/mtd/spi-nor/core.c
> @@ -3009,13 +3009,15 @@ static int spi_nor_set_addr_width(struct spi_nor *nor)
> /* already configured from SFDP */
> } else if (nor->info->addr_width) {
> nor->addr_width = nor->info->addr_width;
> - } else if (nor->mtd.size > 0x1000000) {
> - /* enable 4-byte addressing if the device exceeds 16MiB */
> - nor->addr_width = 4;
> } else {
> nor->addr_width = 3;
> }
>
> + if (nor->addr_width == 3 && nor->mtd.size > 0x1000000) {
Nitpick: ^^^^^^^^^^^^^^^^^^^^^^^^ you can drop this part. But its
fine either way.

Reviewed-by: Pratyush Yadav <p.yadav@xxxxxx>

> + /* enable 4-byte addressing if the device exceeds 16MiB */
> + nor->addr_width = 4;
> + }
> +
> if (nor->addr_width > SPI_NOR_MAX_ADDR_WIDTH) {
> dev_dbg(nor->dev, "address width is too large: %u\n",
> nor->addr_width);

--
Regards,
Pratyush Yadav
Texas Instruments India