On Sunday 10 April 2016 07:35 PM, Jonathan Cameron wrote:
On 06/04/16 15:58, Laxman Dewangan wrote:
Hi Daniel,
On Wednesday 06 April 2016 07:19 PM, Daniel Baluta wrote:
On Wed, Apr 6, 2016 at 1:31 PM, Laxman Dewangan <ldewangan@xxxxxxxxxx> wrote:
Some of kernel driver uses the IIO framework to get the sensor
value via ADC or IIO HW driver. The client driver get iio channel
by iio_channel_get() and release it by calling iio_channel_release().
Add resource managed version (devm_*) of these APIs so that if client
calls the devm_iio_channel_get() then it need not to release it explicitly,
it can be done by managed device framework when driver get un-binded.
This reduces the code in error path and also need of .remove callback in
some cases.
Please provide at least one example of code that uses this API.
Most of client for this APIs are in other subsystem.
When I was working on the patch
[PATCH 2/2] thermal: generic-adc: Add ADC based thermal sensor driver
if I have devm_iio_channel_get() then I can get .remove callback at all.
I did not use this new APIs in my patch because they are in different subsystem.
It's actually worse than that having taken a quick look at the generic-adc thermal patch
you reference above.
(perhaps worth cc'ing linux-iio for next version of that).
Sure. I will CC.
Without this devm function set you have a race in remove in which I think you can
get attempts to access the channels after they have been released...
Yaah, possibly race for very small time possible.
The limitation of devm_ api usage is that, we can keep using this till
we have devm_ api continuous and if some resource are not there for
devm_ then we can not use further.
Possibly, I need to wait for the devm_iio_channel_get() to merge and
available for all subsystem to use (next release) and then only I can
use devm_thermal_zone_of_sensor_register().
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