This is a note to let you know that I've just added the patch titled hwmon: (pmbus/ibm-cffps) max_power_out swap changes to the 5.10-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: hwmon-pmbus-ibm-cffps-max_power_out-swap-changes.patch and it can be found in the queue-5.10 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit e6ecbfca0ce989d2a38dcd50437e7df96b8dd40a Author: Brandon Wyman <bjwyman@xxxxxxxxx> Date: Tue Sep 28 20:50:51 2021 +0000 hwmon: (pmbus/ibm-cffps) max_power_out swap changes [ Upstream commit f067d5585cda2de1e47dde914a8a4f151659e0ad ] The bytes for max_power_out from the ibm-cffps devices differ in byte order for some power supplies. The Witherspoon power supply returns the bytes in MSB/LSB order. The Rainier power supply returns the bytes in LSB/MSB order. The Witherspoon power supply uses version cffps1. The Rainier power supply should use version cffps2. If version is cffps1, swap the bytes before output to max_power_out. Tested: Witherspoon before: 3148. Witherspoon after: 3148. Rainier before: 53255. Rainier after: 2000. Signed-off-by: Brandon Wyman <bjwyman@xxxxxxxxx> Reviewed-by: Eddie James <eajames@xxxxxxxxxxxxx> Link: https://lore.kernel.org/r/20210928205051.1222815-1-bjwyman@xxxxxxxxx [groeck: Replaced yoda programming] Signed-off-by: Guenter Roeck <linux@xxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/hwmon/pmbus/ibm-cffps.c b/drivers/hwmon/pmbus/ibm-cffps.c index 79bc2032dcb2..da261d32450d 100644 --- a/drivers/hwmon/pmbus/ibm-cffps.c +++ b/drivers/hwmon/pmbus/ibm-cffps.c @@ -171,8 +171,14 @@ static ssize_t ibm_cffps_debugfs_read(struct file *file, char __user *buf, cmd = CFFPS_SN_CMD; break; case CFFPS_DEBUGFS_MAX_POWER_OUT: - rc = i2c_smbus_read_word_swapped(psu->client, - CFFPS_MAX_POWER_OUT_CMD); + if (psu->version == cffps1) { + rc = i2c_smbus_read_word_swapped(psu->client, + CFFPS_MAX_POWER_OUT_CMD); + } else { + rc = i2c_smbus_read_word_data(psu->client, + CFFPS_MAX_POWER_OUT_CMD); + } + if (rc < 0) return rc;