From: Jim Wylder <jwylder@xxxxxxxxxx> commit 3981514180c987a79ea98f0ae06a7cbf58a9ac0f upstream. Currently, when regmap_raw_write() splits the data, it uses the max_raw_write value defined for the bus. For any bus that includes the target register address in the max_raw_write value, the chunked transmission will always exceed the maximum transmission length. To avoid this problem, subtract the length of the register and the padding from the maximum transmission. Signed-off-by: Jim Wylder <jwylder@xxxxxxxxxx Link: https://lore.kernel.org/r/20230517152444.3690870-2-jwylder@xxxxxxxxxx Signed-off-by: Mark Brown <broonie@xxxxxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/base/regmap/regmap.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) --- a/drivers/base/regmap/regmap.c +++ b/drivers/base/regmap/regmap.c @@ -1850,6 +1850,8 @@ int _regmap_raw_write(struct regmap *map size_t val_count = val_len / val_bytes; size_t chunk_count, chunk_bytes; size_t chunk_regs = val_count; + size_t max_data = map->max_raw_write - map->format.reg_bytes - + map->format.pad_bytes; int ret, i; if (!val_count) @@ -1857,8 +1859,8 @@ int _regmap_raw_write(struct regmap *map if (map->use_single_write) chunk_regs = 1; - else if (map->max_raw_write && val_len > map->max_raw_write) - chunk_regs = map->max_raw_write / val_bytes; + else if (map->max_raw_write && val_len > max_data) + chunk_regs = max_data / val_bytes; chunk_count = val_count / chunk_regs; chunk_bytes = chunk_regs * val_bytes;
