RE: [PATCH 2/2] hwmon: (pmbus/max20830) add driver for max20830

> >
> > I may need to keep i2c_smbus_read_i2c_block_data. I'm testing this on
> > an rpi4 and it seems i2c_smbus_read_block_data isn't supported by the
> adapter.
> >
> 
> Odd. I can see that the bcm2835 controller driver sets
> I2C_FUNC_SMBUS_EMUL but not I2C_FUNC_SMBUS_BLOCK_DATA. That
> makes me wonder if the controller really does not support block reads. Any
> chance you can try setting that flag in ./drivers/i2c/busses/i2c-bcm2835.c and
> see what happens ?
> 

I tried using i2c_smbus_read_block_data, and here's some log messages 

[ 6857.261998] max20830: adapter does NOT support I2C_FUNC_SMBUS_BLOCK_DATA
[ 6857.262006] max20830: adapter supports I2C_FUNC_SMBUS_READ_I2C_BLOCK
[ 6857.265228] max20830: i2c_block_data read 32 bytes: '        MAX20830'
[ 6857.265648] max20830: smbus_block_data read 9 bytes: ''

i2c_smbus_read_i2c_block_data returns 32 for 32 bytes read
and the buffer content is expected "MAX20830"

i2c_smbus_read_block_data returned 9 so I think it read the payload length of 1byte
but no data beyond it, hence buffer = ''