Re: [PATCH] i2c: s3c2410: Don't enable PM runtime on the adapter device

[Lars-Peter Clausen <lars-Qo5EllUWu/uELgA04lAiVw@public.gmane.org>]

On 04/16/2015 12:33 PM, Sylwester Nawrocki wrote:
> On 16/04/15 12:10, Charles Keepax wrote:
>> Commit 523c5b89640e ("i2c: Remove support for legacy PM") removed the PM
>> ops from the bus type, which causes the pm operations on the s3c2410
>> adapter device to fail (-ENOSUPP in rpm_callback). The adapter device
>> doesn't get bound to a driver and as such can't have its own pm_runtime
>> callbacks. Previously this was fine as the bus callbacks would have been
>> used, but now this can cause devices which use PM runtime and are
>> attached over I2C to fail to resume.
>>
>> This commit fixes this issue by just doing the PM operations directly on
>> the I2C device, rather than the adapter device in the driver and adding
>> some stub callbacks for runtime suspend and resume.
>>
>> Signed-off-by: Charles Keepax <ckeepax-yzvPICuk2AATkU/dhu1WVueM+bqZidxxQQ4Iyu8u01E@public.gmane.org>
>> ---
>>   drivers/i2c/busses/i2c-s3c2410.c |   21 ++++++++++++++++-----
>>   1 files changed, 16 insertions(+), 5 deletions(-)
>
>> @@ -1253,7 +1253,6 @@ static int s3c24xx_i2c_probe(struct platform_device *pdev)
>>   	platform_set_drvdata(pdev, i2c);
>>
>
> Wouldn't adding
>
> 	pm_runtime_no_callbacks(&pdev->dev);
>
> here let us avoid the runtime resume/suspend stubs?

Or just do pm_runtime_no_callbacks on the adapter device. Preferably in the 
I2C core. That should solve the issue without requiring any other changes.

- Lars