[PATCH v2] hid: enable hid device to suspend/resume asynchronously

[PATCH v2] hid: enable hid device to suspend/resume asynchronously

[Fu, Zhonghui]

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 timing dependency between devices. This
patch enables hid devices to suspend/resume asynchronously. This
will take advantage of multicore and improve system suspend/resume
speed.

Signed-off-by: Zhonghui Fu <zhonghui.fu@linux.intel.com>
---
Changes in v2:
- Amend commit message.

 drivers/hid/hid-core.c |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)

diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c
index 70a11ac..357f3a3 100644
--- a/drivers/hid/hid-core.c
+++ b/drivers/hid/hid-core.c
@@ -2652,6 +2652,7 @@ struct hid_device *hid_allocate_device(void)
 	device_initialize(&hdev->dev);
 	hdev->dev.release = hid_device_release;
 	hdev->dev.bus = &hid_bus_type;
+	device_enable_async_suspend(&hdev->dev);
 
 	hid_close_report(hdev);
 
-- 1.7.1

Re: [PATCH v2] hid: enable hid device to suspend/resume asynchronously

[Fu, Zhonghui]

Hi Jiri,

Any comments about this patch?

After enabling the HID devices suspend/resume asynchronously on ASUS T100TA(Baytrail-T platform), the system suspend-to-idle/resume time is reduced about 20ms. Although this improvement is not very significant. But, if the suspend/resume operation of HID devices is very time-consuming on some other platforms, this patch can improve significantly system suspend/resume speed on these platforms. 



Thanks,
Zhonghui 



On 9/24/2015 2:06 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 timing dependency between devices. This
> patch enables hid devices to suspend/resume asynchronously. This
> will take advantage of multicore and improve system suspend/resume
> speed.
>
> Signed-off-by: Zhonghui Fu <zhonghui.fu@linux.intel.com>
> ---
> Changes in v2:
> - Amend commit message.
>
>  drivers/hid/hid-core.c |    1 +
>  1 files changed, 1 insertions(+), 0 deletions(-)
>
> diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c
> index 70a11ac..357f3a3 100644
> --- a/drivers/hid/hid-core.c
> +++ b/drivers/hid/hid-core.c
> @@ -2652,6 +2652,7 @@ struct hid_device *hid_allocate_device(void)
>  	device_initialize(&hdev->dev);
>  	hdev->dev.release = hid_device_release;
>  	hdev->dev.bus = &hid_bus_type;
> +	device_enable_async_suspend(&hdev->dev);
>  
>  	hid_close_report(hdev);
>  
> -- 1.7.1
>

Re: [PATCH v2] hid: enable hid device to suspend/resume asynchronously

[Jiri Kosina]

On Mon, 16 Nov 2015, Fu, Zhonghui wrote:

> 
> Hi Jiri,
> 
> Any comments about this patch?
> 
> After enabling the HID devices suspend/resume asynchronously on ASUS 
> T100TA(Baytrail-T platform), the system suspend-to-idle/resume time is 
> reduced about 20ms. Although this improvement is not very significant. 
> But, if the suspend/resume operation of HID devices is very 
> time-consuming on some other platforms, this patch can improve 
> significantly system suspend/resume speed on these platforms.

Hi,

I don't think the question I've raised at

	http://lkml.kernel.org/r/alpine.LNX.2.00.1509251404130.30132@pobox.suse.cz

has ever been answered or at least discussed ... ?

-- 
Jiri Kosina
SUSE Labs

Re: [PATCH v2] hid: enable hid device to suspend/resume asynchronously

[Fu, Zhonghui]

On 11/16/2015 11:26 PM, Jiri Kosina wrote:
> On Mon, 16 Nov 2015, Fu, Zhonghui wrote:
>
>> Hi Jiri,
>>
>> Any comments about this patch?
>>
>> After enabling the HID devices suspend/resume asynchronously on ASUS 
>> T100TA(Baytrail-T platform), the system suspend-to-idle/resume time is 
>> reduced about 20ms. Although this improvement is not very significant. 
>> But, if the suspend/resume operation of HID devices is very 
>> time-consuming on some other platforms, this patch can improve 
>> significantly system suspend/resume speed on these platforms.
> Hi,
>
> I don't think the question I've raised at
>
> 	http://lkml.kernel.org/r/alpine.LNX.2.00.1509251404130.30132@pobox.suse.cz
>
> has ever been answered or at least discussed ... ?
Sorry for missing this mail.

At present, the file(/sys/.../power/async) can be used to enable one device suspend/resume asynchronously.  My patch only changes the default value of this file from "disabled" to "enabled".
The sole difference of asynchronous suspend/resume mode is that the suspend/resume operation of one device is carried out in a separate kernel thread, and PM core ensures all related dependency. I have verified this patch on some platforms, such as ASUS T100TA. Actually, many other devices have used this feature for a long time.


Thanks,
Zhonghui
>

Re: [PATCH v2] hid: enable hid device to suspend/resume asynchronously

[Jiri Kosina]

On Thu, 24 Sep 2015, 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 timing dependency between devices. This
> patch enables hid devices to suspend/resume asynchronously. This
> will take advantage of multicore and improve system suspend/resume
> speed.
> 
> Signed-off-by: Zhonghui Fu <zhonghui.fu@linux.intel.com>
> ---
> Changes in v2:
> - Amend commit message.
> 
>  drivers/hid/hid-core.c |    1 +
>  1 files changed, 1 insertions(+), 0 deletions(-)
> 
> diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c
> index 70a11ac..357f3a3 100644
> --- a/drivers/hid/hid-core.c
> +++ b/drivers/hid/hid-core.c
> @@ -2652,6 +2652,7 @@ struct hid_device *hid_allocate_device(void)
>  	device_initialize(&hdev->dev);
>  	hdev->dev.release = hid_device_release;
>  	hdev->dev.bus = &hid_bus_type;
> +	device_enable_async_suspend(&hdev->dev);

Applied to for-4.5/async-suspend branch.

-- 
Jiri Kosina
SUSE Labs