From: Jim Wylder jwylder@google.com
[ Upstream commit 3981514180c987a79ea98f0ae06a7cbf58a9ac0f ]
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@google.com Link: https://lore.kernel.org/r/20230517152444.3690870-2-jwylder@google.com Signed-off-by: Mark Brown <broonie@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/base/regmap/regmap.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/drivers/base/regmap/regmap.c b/drivers/base/regmap/regmap.c index 55a30afc14a00..2a3c3dfefdcec 100644 --- a/drivers/base/regmap/regmap.c +++ b/drivers/base/regmap/regmap.c @@ -1998,6 +1998,8 @@ int _regmap_raw_write(struct regmap *map, unsigned int reg, 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) @@ -2005,8 +2007,8 @@ int _regmap_raw_write(struct regmap *map, unsigned int reg,
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;