On 2/15/26 9:31 PM, Jonathan Cameron wrote: > On Sun, 15 Feb 2026 19:28:56 +0200 > Erikas Bitovtas <[email protected]> wrote: > >> On 2/14/26 8:09 PM, Jonathan Cameron wrote: >>>> --- >>>> drivers/iio/light/vcnl4000.c | 40 ++++++++++++++++++++++++++++++++++++++++ >>>> 1 file changed, 40 insertions(+) >>>> >>>> diff --git a/drivers/iio/light/vcnl4000.c b/drivers/iio/light/vcnl4000.c >>>> index a36c23813679..1f8f4e4586f4 100644 >>>> --- a/drivers/iio/light/vcnl4000.c >>>> +++ b/drivers/iio/light/vcnl4000.c >>>> @@ -185,6 +185,7 @@ static const int vcnl4040_ps_oversampling_ratio[] = >>>> {1, 2, 4, 8}; >>>> #define VCNL4000_SLEEP_DELAY_MS 2000 /* before we enter >>>> pm_runtime_suspend */ >>>> >>>> enum vcnl4000_device_ids { >>>> + CM36672P, >>>> VCNL4000, >>>> VCNL4010, >>>> VCNL4040, >>>> @@ -235,6 +236,8 @@ struct vcnl4000_chip_spec { >>>> }; >>>> >>>> static const struct i2c_device_id vcnl4000_id[] = { >>>> + { "cm36672p", CM36672P }, >>>> + { "cm36686", VCNL4040 }, >>>> { "vcnl4000", VCNL4000 }, >>>> { "vcnl4010", VCNL4010 }, >>>> { "vcnl4020", VCNL4010 }, >>>> @@ -1842,6 +1845,22 @@ static const struct iio_chan_spec >>>> vcnl4040_channels[] = { >>>> } >>>> }; >>> >>> ... >>> >>>> [VCNL4000] = { >>>> .prod = "VCNL4000", >>>> .init = vcnl4000_init, >>>> @@ -2033,6 +2065,14 @@ static int vcnl4000_probe(struct i2c_client *client) >>>> } >>>> >>>> static const struct of_device_id vcnl_4000_of_match[] = { >>>> + { >>>> + .compatible = "capella,cm36672p", >>>> + .data = (void *)CM36672P, >>>> + }, >>>> + { >>>> + .compatible = "capella,cm36686", >>>> + .data = (void *)VCNL4040, >>> >>> Is this necessary? I 'think' if you drop it we'll match instead >>> on the vcnl4040 fallback and then the access to the data will be >>> through the stripped name only bit of the compatible (first entry, not >>> the fallback so cm36686 in this case). So you do need the cm36686 >>> entry in the i2c_device_id table above. Probably better to keep >>> this here to avoid having to reason this out - but perhaps a >>> comment to that affect would be useful (assuming you verify my >>> reasoning). >>> >> After I removed the entry for "capella,cm36686", I received the "Unable >> to handle kernel NULL pointer dereference" error in dmesg. And at least >> stk3310 driver includes a compatible entry both for the device (stk3013) >> and for the fallback (stk3310). So my assumption is that this entry is >> needed. >> I could include a comment explaining that cm36686 is fully compatible >> with vcnl4040, however, if that is necessary. > > Thanks for checking. > > What did you get as the backtrace? I'm hoping it'll explain what I'm > misunderstanding! The hacks around using the wrong table for compatible > matches have tripped me up before. > > Jonathan >
I am attaching a link to the dmesg. There were quite a lot of lines in the stack trace and I am not sure what is the right way to post logs in the mailing list. https://pastebin.com/QgeTdNEP

