On Fri, Jun 21, 2024 at 2:26 PM Hans de Goede <hdegoede@xxxxxxxxxx> wrote: > > Unfortunately the SMOxxxx ACPI device does not contain the i2c-address > of the accelerometer. So a DMI product-name to address mapping table > is used. > > At support to have the kernel probe for the i2c-address for modesl At --> Add ? models > which are not on the list. > > The new probing code sits behind a new probe_i2c_addr module parameter, > which is disabled by default because probing might be dangerous. ... > +/* > + * This is the kernel version of the single register device sanity checks from > + * the i2c_safety_check function from lm_sensors sensor-detect script: i2c_safety_check() > + * This is meant to prevent access to 1-register-only devices, > + * which are designed to be accessed with SMBus receive byte and SMBus send > + * byte transactions (i.e. short reads and short writes) and treat SMBus > + * read byte as a real write followed by a read. The device detection > + * routines would write random values to the chip with possibly very nasty > + * results for the hardware. Note that this function won't catch all such > + * chips, as it assumes that reads and writes relate to the same register, > + * but that's the best we can do. > + */ ... > + err = i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_READ, data ^ 0x01, Is 0x01 defined already? Or BIT(0) ? > + I2C_SMBUS_BYTE_DATA, &smbus_data); > + if (err < 0) > + return err; > + > + if (smbus_data.byte != (data ^ 0x01)) Ditto. > + return 0; /* Not a 1-register-only device. */ ... > + dev_info(&device->dev, "Pass dell_smo8800.probe_i2c_addr=1 on the kernel commandline to probe, this may be dangerous!\n"); command line ...or... cmdline -- With Best Regards, Andy Shevchenko
