Requesting that this regmap fix be cherry picked into the active stable releases 5.15 and later (5.15 being the earliest I was able to test).
Commit 3981514180c987a79ea98f0ae06a7cbf58a9ac0f fixes a error in _regmap_raw_write() when chunking a transmission larger than the maximum write size for the bus and when bus writes the address and any padding along with the data.
Jim
The original commit message is:
------ commit 3981514180c987a79ea98f0ae06a7cbf58a9ac0f Author: Jim Wylder jwylder@google.com Date: Wed May 17 10:20:11 2023 -0500
regmap: Account for register length when chunking
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 ------