Newer batches of several Mikrotik boards contain this yet-unsupported
flash chip, for instance:
- rb941-2nd (hAP lite)
- rb952ui-5ac2nd (hAP ac lite)
- RBM33G
and probably other Mikrotik boards need this patch as well.
The patch was submitted upstream by Robert Marko: https://patchwork.ozlabs.org/patch/934181/
Closes: FS#1715
Signed-off-by: Baptiste Jonglez <git@bitsofnetworks.org>
Cc: Robert Marko <robimarko@gmail.com>
Some board vendors actually changed the loader to expect the chip
to come up in 4-address-mode and flipped the ADP bit in the flash
chip's configuration register which makes it come up in 4-address-mode.
Hence it doesn't make sense to avoid switching to 4-address-mode on
those boards but the opposite as otherwise reboot hangs eg. on the
WrtNode2 boards. Fix this by checking the ADP register and only using
SPI_NOR_4B_READ_OP on chips which have ADP==0 (come up in 3-byte mode).
See also datasheet section 7.1.11 Power Up Address Mode (ADP)
Fixes: 22d982ea0 ("ramips: add support for switching between 3-byte and 4-byte addressing on w25q256 flash")
Signed-off-by: Daniel Golle <daniel@makrotopia.org>
