Re: [RESEND PATCH 7/7] regulator: isl9305: Export OF module alias information
From: Javier Martinez Canillas
Date: Tue Aug 25 2015 - 13:33:45 EST
On 08/25/2015 06:20 PM, Mark Brown wrote:
> On Tue, Aug 25, 2015 at 08:31:17AM +0200, Javier Martinez Canillas wrote:
>> The I2C core always reports the MODALIAS uevent as "i2c:<modalias>"
>> regardless of the mechanism that was used to register the device
>> (i.e: OF or board code) and the table that is used later to match
>> the driver with the device (i.e: I2C id table or OF match table).
>> So drivers needs to export the I2C id table and this be built into
>> the module or udev won't have the necessary information to autoload
>> the needed driver module when the device is added.
>> But this means that OF-only drivers needs to have both OF and I2C id
>> tables that have to be kept in sync and also the dev node compatible
>> manufacturer prefix is stripped when reporting the MODALIAS. Which can
>> lead to issues if two vendors use the same I2C device name for example.
>> To avoid the above, the I2C core behavior may be changed in the future
>> to not require an SPI device table for OF-only drivers and report the
>> OF module alias. So, it's better to also export the OF table even when
>> is unused now to prevent breaking module loading when the core changes.
> So, on the one hand detailed commit messages are nice. On the other
> hand if they wander too far off point it can be hard to sustain
> interest and one can glaze over a bit. All the above really needs to
> say is that if we want to use the OF alias table we need to export it.
Ok, I wanted to explain why needs to be added even if currently
is not used. But I'll post a v2 with a shorter commit message.
Javier Martinez Canillas
Open Source Group
Samsung Research America
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