[U-Boot] Between 2015.10 and 2016.01, SPI flash changed erase size, and saveenv stopped working

[Fabio Estevam]

On Mon, May 30, 2016 at 5:33 AM, Pavel Machek <pavel at denx.de> wrote:

> Commit c3c016cf75360c2a0d0a065b64b438aaf7720576 is a part of the problem:
>
> offset 0x40000 is protected and cannot be erased
> => sf help
> No SPI flash selected. Please run `sf probe'
> => sf probe
> ...
> SF: Detected N25Q512 with page size 256 Bytes, erase size 4 KiB, total
> 64 MiB
> cadence_spi_set_speed: speed=1000000
> => sf protect unlock 0x40000 0x20000
> cadence_spi_xfer: len=1 [bytes]
> cadence_spi_xfer: len=1 [bytes]
> => saveenv
> Saving Environment to SPI Flash...

Does this quick hack help? I am wondering if yous SPI flash power up
with the SR field protected:

--- a/drivers/mtd/spi/spi_flash.c
+++ b/drivers/mtd/spi/spi_flash.c
@@ -1021,11 +1021,7 @@ int spi_flash_scan(struct spi_flash *flash)
                return -EPROTONOSUPPORT;
        }

-       /* Flash powers up read-only, so clear BP# bits */
-       if (idcode[0] == SPI_FLASH_CFI_MFR_ATMEL ||
-           idcode[0] == SPI_FLASH_CFI_MFR_MACRONIX ||
-           idcode[0] == SPI_FLASH_CFI_MFR_SST)
-               write_sr(flash, 0);
+       write_sr(flash, 0);

        /* Assign spi data */
        flash->name = params->name;