[RESEND PATCH] mtd: spi-nor: core: Check written SR value in spi_nor_write_16bit_sr_and_check()

[Chen-Tsung Hsieh]

On Thu, Jan 27, 2022 at 5:18 PM Michael Walle <michael at walle.cc> wrote:
> Ah that ring a bell... Anyway, could you dump the SFDP data please?
> See [1], you'll find the files in sysfs. I wonder why that flash is
> using the 16bit write at all.
>
> [1]
> https://lore.kernel.org/linux-mtd/4304e19f3399a0a6e856119d01ccabe0@walle.cc/

Dump SFDP data:
# xxd -p /sys/class/mtd/mtd0/device/spi-nor/sfdp
53464450060101ff00060110800000ff84000102d00000ffffffffffffff
ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff
ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff
ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff
ffffffffffffffffe520f9ffffffff0344eb086b083b42bbfeffffffffff
0000ffff40eb0c200f5210d800003602a60082ea14c4e96376337a757a75
f7bdd55c19f75dffe930f880ffffffffffffffffffffffffffffffff0000
f0ffffffffff
# md5sum /sys/class/mtd/mtd0/device/spi-nor/sfdp
5294c4d4eb2b1c89c6fd8573d8ceaa2d  /sys/class/mtd/mtd0/device/spi-nor/sfdp
# cat /sys/class/mtd/mtd0/device/spi-nor/jedec_id
ef8017
# cat /sys/class/mtd/mtd0/device/spi-nor/partname
w25q64jwm
# cat /sys/class/mtd/mtd0/device/spi-nor/manufacturer
winbond

"bfpt.dwords[BFPT_DWORD(15)]" is 0xff5df719, and flag
SNOR_F_HAS_16BIT_SR is set here:
        case BFPT_DWORD15_QER_SR2_BIT1:
                /*
                 * JESD216 rev B or later does not specify if writing only one
                 * byte to the Status Register clears or not the Status
                 * Register 2, so let's be cautious and keep the default
                 * assumption of a 16-bit Write Status (01h) command.
                 */
                nor->flags |= SNOR_F_HAS_16BIT_SR;
                params->quad_enable = spi_nor_sr2_bit1_quad_enable;
                break;