We should add 1 to the max_register index since counting is zero based. i.e. the stm32mp151 bsec has registers 0 - 95 with reg_stride 4. Size should be (95 + 1) * 4 = 384 bytes otherwise we can't access bsec register 95 (last one). regmap_size_bytes() does take the +1 into account so we can use that. Signed-off-by: Robin van der Gracht <robin@xxxxxxxxxxx> --- v2: Fix the size calculation in nvmem_regmap_read() as well. drivers/nvmem/regmap.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/nvmem/regmap.c b/drivers/nvmem/regmap.c index fa5405d7a8..b923c5787d 100644 --- a/drivers/nvmem/regmap.c +++ b/drivers/nvmem/regmap.c @@ -38,7 +38,7 @@ static int nvmem_regmap_read(void *ctx, unsigned offset, void *buf, size_t bytes skip_bytes = offset & (stride - 1); rbytes = roundup(bytes + skip_bytes, stride); - if (roffset + rbytes > stride * regmap_get_max_register(map)) + if (roffset + rbytes > regmap_size_bytes(map) * stride) return -EINVAL; for (i = roffset; i < roffset + rbytes; i += stride) { @@ -78,7 +78,7 @@ nvmem_regmap_register_with_pp(struct regmap *map, const char *name, config.priv = map; config.stride = 1; config.word_size = 1; - config.size = regmap_get_max_register(map) * regmap_get_reg_stride(map); + config.size = regmap_size_bytes(map) * regmap_get_reg_stride(map); config.cell_post_process = cell_post_process; config.reg_write = nvmem_regmap_write; config.reg_read = nvmem_regmap_read; -- 2.40.1