Re: lm90 driver no longer working on PCs in 3.13

From: Jean Delvare
Date: Sun Jan 26 2014 - 15:14:16 EST


Hi Guenter,

Adding Wei Ni to Cc, as he provided the commit which causes problem.

On Sun, 26 Jan 2014 11:28:16 -0800, Guenter Roeck wrote:
> Hi,
>
> the lm90 driver is no longer working on PCs with the 3.13 kernel ... or at least not without
> special configuration.
>
> This is what I get if I try to instantiate a device on it (max6695):
>
> i2c 1-0018: Driver lm90 requests probe deferral
> i2c i2c-1: new_device: Instantiated device max6695 at 0x18
>
> The regulator core always returns -EPROBE_DEFER if the platform does not support devicetree
> and if the regulator it is looking for does not exist. Since the driver now requires a mandatory
> regulator (commit 3e0f964f2ad - hwmon: (lm90) Add power control), and the regulator it requests
> does not exist on a PC, the result is not really surprising. I thought the regulator core would
> realize that it has to return a dummy regulator, but apparently that is not the case, or I don't
> know how to configure it.
>
> Any idea what I might need to do to get it working ?

Me, I really don't know. I seem to remember I tested Wei's patch set on
an emulated ADM1032 chip and it was working fine. So maybe it depends
on the kernel configuration, or something changed on the regulator side
meanwhile.

--
Jean Delvare
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