Re: [PATCH 1/2] i2c: enable i2c device to suspend/resume asynchronously

["Fu, Zhonghui" <zhonghui.fu@linux.intel.com>]

Hi Wolfram,

What do you think about this patch?


Thanks,
Zhonghui



On 12/24/2015 10:41 PM, Fu, Zhonghui wrote:
> Now, PM core supports asynchronous suspend/resume mode for devices
> during system suspend/resume, and the power state transition of one
> device may be completed in separate kernel thread. PM core ensures
> all power state transition dependency between devices. This patch
> enables i2c devices to suspend/resume asynchronously. This will take
> advantage of multicore and improve system suspend/resume speed. After
> enabling all i2c devices, i2c adapters and i2c controllers on ASUS
> T100TA tablet, the system suspend-to-idle time is reduced to about
> 510ms from 750ms, and the system resume time is reduced to about 790ms
> from 900ms.
>
> Signed-off-by: Zhonghui Fu <zhonghui.fu@linux.intel.com>
> ---
>  drivers/i2c/i2c-core.c |    1 +
>  1 files changed, 1 insertions(+), 0 deletions(-)
>
> diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
> index ba8eb08..4ff620e 100644
> --- a/drivers/i2c/i2c-core.c
> +++ b/drivers/i2c/i2c-core.c
> @@ -1072,6 +1072,7 @@ i2c_new_device(struct i2c_adapter *adap, struct i2c_board_info const *info)
>  	client->dev.of_node = info->of_node;
>  	client->dev.fwnode = info->fwnode;
>  
> +	device_enable_async_suspend(&client->dev);
>  	i2c_dev_set_name(adap, client);
>  	status = device_register(&client->dev);
>  	if (status)
> -- 1.7.1
>