Re: [PATCH] i2c/designware: enable i2c controller to suspend/resume asynchronously

[Jarkko Nikula]

Hi

On 12/24/2015 04:30 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 designware i2c controllers 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.


Nice reduction :-)


diff --git a/drivers/i2c/busses/i2c-designware-platdrv.c 
b/drivers/i2c/busses/i2c-designware-platdrv.c
index 6b00061..395130b 100644
--- a/drivers/i2c/busses/i2c-designware-platdrv.c
+++ b/drivers/i2c/busses/i2c-designware-platdrv.c
@@ -230,6 +230,7 @@ static int dw_i2c_plat_probe(struct platform_device *pdev)
}

adap = >adapter;
+   device_enable_async_suspend(>dev);
adap->owner = THIS_MODULE;
adap->class = I2C_CLASS_DEPRECATED;
ACPI_COMPANION_SET(>dev, ACPI_COMPANION(>dev));


Does device_enable_async_suspend() need to be called before enabling 
runtime PM? I suppose not since there appears to have also related sysfs 
node for toggling it runtime.


I'm thinking if you could move the device_enable_async_suspend() call 
into drivers/i2c/busses/i2c-designware-core.c: i2c_dw_probe() and then 
also PCI enumerated adapter could take advantage of it.


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Jarkko
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Re: [PATCH] i2c/designware: enable i2c controller to suspend/resume asynchronously

[Andy Shevchenko]

On Tue, 2016-01-05 at 10:53 +0200, Jarkko Nikula wrote:
> Hi
> 
> On 12/24/2015 04:30 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 designware i2c controllers 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.
> > 
> Nice reduction :-)
> 
> > diff --git a/drivers/i2c/busses/i2c-designware-platdrv.c
> > b/drivers/i2c/busses/i2c-designware-platdrv.c
> > index 6b00061..395130b 100644
> > --- a/drivers/i2c/busses/i2c-designware-platdrv.c
> > +++ b/drivers/i2c/busses/i2c-designware-platdrv.c
> > @@ -230,6 +230,7 @@ static int dw_i2c_plat_probe(struct
> > platform_device *pdev)
> >     }
> > 
> >     adap = >adapter;
> > +   device_enable_async_suspend(>dev);
> >     adap->owner = THIS_MODULE;
> >     adap->class = I2C_CLASS_DEPRECATED;
> >     ACPI_COMPANION_SET(>dev, ACPI_COMPANION(
> > >dev));
> 
> Does device_enable_async_suspend() need to be called before enabling 
> runtime PM? I suppose not since there appears to have also related
> sysfs 
> node for toggling it runtime.
> 
> I'm thinking if you could move the device_enable_async_suspend() call
> into drivers/i2c/busses/i2c-designware-core.c: i2c_dw_probe() and
> then 
> also PCI enumerated adapter could take advantage of it.

I concern about Intel BayTrail-T / Braswell / CherryTrail cases, since
we have non-trivial PM for LPSS there. Zhonghui, have you a chance to
stress test this on platforms based on mentioned SoCs?


-- 
Andy Shevchenko 
Intel Finland Oy

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Re: [PATCH] i2c/designware: enable i2c controller to suspend/resume asynchronously

[Fu, Zhonghui]

Hi,

I have resent this patch with updated commit message - "[PATCH v2] 
i2c/designware: enable i2c controller to suspend/resume asynchronously".


Thanks,
Zhonghui

On 2015/8/24 23:23, Fu, Zhonghui wrote:
> Hi,
>
> Any comments are welcome.
>
>
> Thanks,
> Zhonghui
>
>
>
> On 2015/8/18 0:36, Fu, Zhonghui wrote:
>> Enable i2c controller to suspend/resume asynchronously. This can improve
>> system suspend/resume speed.
>>
>> Signed-off-by: Zhonghui Fu 
>> ---
>>  drivers/i2c/busses/i2c-designware-platdrv.c |1 +
>>  1 files changed, 1 insertions(+), 0 deletions(-)
>>
>> diff --git a/drivers/i2c/busses/i2c-designware-platdrv.c 
>> b/drivers/i2c/busses/i2c-designware-platdrv.c
>> index 3dd2de3..fec0fce 100644
>> --- a/drivers/i2c/busses/i2c-designware-platdrv.c
>> +++ b/drivers/i2c/busses/i2c-designware-platdrv.c
>> @@ -245,6 +245,7 @@ static int dw_i2c_probe(struct platform_device *pdev)
>>  
>>  adap = >adapter;
>>  i2c_set_adapdata(adap, dev);
>> +device_enable_async_suspend(>dev);
>>  adap->owner = THIS_MODULE;
>>  adap->class = I2C_CLASS_DEPRECATED;
>>  strlcpy(adap->name, "Synopsys DesignWare I2C adapter",
>> -- 1.7.1
>>

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Re: [PATCH] i2c/designware: enable i2c controller to suspend/resume asynchronously

[Fu, Zhonghui]

Hi,

Any comments are welcome.


Thanks,
Zhonghui



On 2015/8/18 0:36, Fu, Zhonghui wrote:
 Enable i2c controller to suspend/resume asynchronously. This can improve
 system suspend/resume speed.

 Signed-off-by: Zhonghui Fu zhonghui...@linux.intel.com
 ---
  drivers/i2c/busses/i2c-designware-platdrv.c |1 +
  1 files changed, 1 insertions(+), 0 deletions(-)

 diff --git a/drivers/i2c/busses/i2c-designware-platdrv.c 
 b/drivers/i2c/busses/i2c-designware-platdrv.c
 index 3dd2de3..fec0fce 100644
 --- a/drivers/i2c/busses/i2c-designware-platdrv.c
 +++ b/drivers/i2c/busses/i2c-designware-platdrv.c
 @@ -245,6 +245,7 @@ static int dw_i2c_probe(struct platform_device *pdev)
  
   adap = dev-adapter;
   i2c_set_adapdata(adap, dev);
 + device_enable_async_suspend(pdev-dev);
   adap-owner = THIS_MODULE;
   adap-class = I2C_CLASS_DEPRECATED;
   strlcpy(adap-name, Synopsys DesignWare I2C adapter,
 -- 1.7.1


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