On Thu, Jun 10, 2021 at 12:56 PM Stephan Gerhold [off-list ref] wrote:

Commit 0ad4bf370176 ("iio:accel:bmc150-accel: Use the chip ID to detect
sensor variant") stopped using the I2C/ACPI match data to look up the
bmc150_accel_chip_info. However, the bmc150_accel_chip_info_tbl remained
as-is, with multiple entries with the same chip_id (e.g. 0xFA for
BMC150/BMI055/BMA255). This is redundant now because actually the driver
will always select the first entry with a matching chip_id.

So even if a device probes e.g. with BMA0255 it will end up using the
chip_info for BMC150. And in general that's fine for now, the entries
for BMC150/BMI055/BMA255 were exactly the same anyway (except for the
name, which is replaced with the more accurate one later).

But in this case it's misleading because it suggests that one should
add even more entries with the same chip_id when adding support for
new variants. Let's make that more clear by removing the enum with
the chip identifiers entirely and instead have only one entry per
chip_id.

Note that we may need to bring back some mechanism to differentiate
between different chips with the same chip_id in the future.
For example, BMA250 (currently supported by the bma180 driver) has the
same chip_id = 0x03 as BMA222 even though they have different channel
sizes (8 bits vs 10 bits). But in any case, that mechanism would
need to look quite different from what we have right now.

...

 static const struct bmc150_accel_chip_info bmc150_accel_chip_info_tbl[] = {

Perhaps sort this by chip_id value?

...

 static const struct acpi_device_id bmc150_accel_acpi_match[] = {
-       {"BSBA0150",    bmc150},
-       {"BMC150A",     bmc150},
-       {"BMI055A",     bmi055},
-       {"BMA0255",     bma255},
-       {"BMA250E",     bma250e},
-       {"BMA222",      bma222},
-       {"BMA222E",     bma222e},
-       {"BMA0280",     bma280},
+       {"BSBA0150"},
+       {"BMC150A"},
+       {"BMI055A"},
+       {"BMA0255"},
+       {"BMA250E"},
+       {"BMA222"},
+       {"BMA222E"},
+       {"BMA0280"},
        {"BOSC0200"},
        {"DUAL250E"},

I have noticed during review patch 3 that the arrays are unsorted, can
we at the same time sort them by ID, please?

...

 static const struct i2c_device_id bmc150_accel_id[] = {

Ditto.

        {}
 };

...

 static const struct acpi_device_id bmc150_accel_acpi_match[] = {

Ditto.

        { },
 };

...

 static const struct spi_device_id bmc150_accel_id[] = {

Ditto.

        {}
 };

-- 
With Best Regards,
Andy Shevchenko