| Message ID | 20240127092516.1641-1-aladyshev22@gmail.com (mailing list archive) |
|---|---|
| State | Rejected |
| Headers | show |
| Series | [v4] hwmon: (pmbus/mp2975) Fix driver initialization for MP2975 device | expand |
On 1/27/24 01:25, Konstantin Aladyshev wrote: > The commit 1feb31e810b0 ("hwmon: (pmbus/mp2975) Simplify VOUT code") > has introduced a bug that makes it impossible to initialize MP2975 > device: > """ > mp2975 5-0020: Failed to identify chip capabilities > i2c i2c-5: new_device: Instantiated device mp2975 at 0x20 > i2c i2c-5: delete_device: Deleting device mp2975 at 0x20 > """ > Since the 'read_byte_data' function was removed from the > 'pmbus_driver_info ' structure the driver no longer reports correctly > that VOUT mode is direct. Therefore 'pmbus_identify_common' fails > with error, making it impossible to initialize the device. > > Restore 'read_byte_data' function to fix the issue. > > Tested: > - before: it is not possible to initialize MP2975 device with the > 'mp2975' driver, > - after: 'mp2975' correctly initializes MP2975 device and all sensor > data is correct. > > Fixes: 1feb31e810b0 ("hwmon: (pmbus/mp2975) Simplify VOUT code") > > Signed-off-by: Konstantin Aladyshev <aladyshev22@gmail.com> > --- > Changes in v4: > - Correct comment inside the 'mp2975_read_byte_data' function as > suggested by Patrick Rudolph > I already applied version 3 of the patch. Feel free to send a follow-up to that patch. It is too late for a v4 of the original patch. Guenter
diff --git a/drivers/hwmon/pmbus/mp2975.c b/drivers/hwmon/pmbus/mp2975.c index b9bb469e2d8f..e5fa10b3b8bc 100644 --- a/drivers/hwmon/pmbus/mp2975.c +++ b/drivers/hwmon/pmbus/mp2975.c @@ -126,6 +126,21 @@ static const struct regulator_desc __maybe_unused mp2975_reg_desc[] = { #define to_mp2975_data(x) container_of(x, struct mp2975_data, info) +static int mp2975_read_byte_data(struct i2c_client *client, int page, int reg) +{ + switch (reg) { + case PMBUS_VOUT_MODE: + /* + * Report direct format as configured by MFR_DC_LOOP_CTRL. + * Unlike on MP2971/MP2973 the reported VOUT_MODE isn't automatically + * internally updated, but always reads as PB_VOUT_MODE_VID. + */ + return PB_VOUT_MODE_DIRECT; + default: + return -ENODATA; + } +} + static int mp2975_read_word_helper(struct i2c_client *client, int page, int phase, u8 reg, u16 mask) @@ -869,6 +884,7 @@ static struct pmbus_driver_info mp2975_info = { PMBUS_HAVE_IIN | PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT | PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP | PMBUS_HAVE_POUT | PMBUS_HAVE_PIN | PMBUS_HAVE_STATUS_INPUT | PMBUS_PHASE_VIRTUAL, + .read_byte_data = mp2975_read_byte_data, .read_word_data = mp2975_read_word_data, #if IS_ENABLED(CONFIG_SENSORS_MP2975_REGULATOR) .num_regulators = 1,
The commit 1feb31e810b0 ("hwmon: (pmbus/mp2975) Simplify VOUT code") has introduced a bug that makes it impossible to initialize MP2975 device: """ mp2975 5-0020: Failed to identify chip capabilities i2c i2c-5: new_device: Instantiated device mp2975 at 0x20 i2c i2c-5: delete_device: Deleting device mp2975 at 0x20 """ Since the 'read_byte_data' function was removed from the 'pmbus_driver_info ' structure the driver no longer reports correctly that VOUT mode is direct. Therefore 'pmbus_identify_common' fails with error, making it impossible to initialize the device. Restore 'read_byte_data' function to fix the issue. Tested: - before: it is not possible to initialize MP2975 device with the 'mp2975' driver, - after: 'mp2975' correctly initializes MP2975 device and all sensor data is correct. Fixes: 1feb31e810b0 ("hwmon: (pmbus/mp2975) Simplify VOUT code") Signed-off-by: Konstantin Aladyshev <aladyshev22@gmail.com> --- Changes in v4: - Correct comment inside the 'mp2975_read_byte_data' function as suggested by Patrick Rudolph Changes in v3: - Drop accidentally added file from patch Changes in v2: - Fix indentation issues drivers/hwmon/pmbus/mp2975.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+)