In function ubi_nvmem_reg_read the while-loop can only be exiting
of bytes_left is zero or an error has occurred. There is an exit
return path if an error occurs, so the bytes_left can only be
zero after that point. Hence the check for a non-zero bytes_left
at the end of the function is redundant and can be removed. Remove
the check and just return 0.
Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Reviewed-by: Zhihao Cheng <chengzhihao1@huawei.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
The use of do_div() in ubi_nvmem_reg_read() makes calling it on
32-bit machines rather expensive. Since the 'from' variable is
known to be a 32-bit quantity, it is clearly never needed and
can be optimized into a regular division operation.
Fixes: b8a77b9a5f ("mtd: ubi: fix NVMEM over UBI volumes on 32-bit systems")
Fixes: 3ce485803d ("mtd: ubi: provide NVMEM layer over UBI volumes")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Zhihao Cheng <chengzhihao1@huawei.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
A compiler warning related to sizeof(int) != 8 when calling do_div()
is triggered when building on 32-bit platforms.
Address this by using integer types having a well-defined size.
Fixes: 3ce485803d ("mtd: ubi: provide NVMEM layer over UBI volumes")
Signed-off-by: Daniel Golle <daniel@makrotopia.org>
Reviewed-by: Zhihao Cheng <chengzhihao1@huawei.com>
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Richard Weinberger <richard@nod.at>
In an ideal world we would like UBI to be used where ever possible on a
NAND chip. And with UBI support in ARM Trusted Firmware and U-Boot it
is possible to achieve an (almost-)all-UBI flash layout. Hence the need
for a way to also use UBI volumes to store board-level constants, such
as MAC addresses and calibration data of wireless interfaces.
Add UBI volume NVMEM driver module exposing UBI volumes as NVMEM
providers. Allow UBI devices to have a "volumes" firmware subnode with
volumes which may be compatible with "nvmem-cells".
Access to UBI volumes via the NVMEM interface at this point is
read-only, and it is slow, opening and closing the UBI volume for each
access due to limitations of the NVMEM provider API.
Signed-off-by: Daniel Golle <daniel@makrotopia.org>
Signed-off-by: Richard Weinberger <richard@nod.at>
