Messages in this thread | | | Subject | Re: [PATCH] i2c/designware: enable i2c controller to suspend/resume asynchronously | From | Jarkko Nikula <> | Date | Tue, 5 Jan 2016 10:53:35 +0200 |
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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 = &dev->adapter; > + device_enable_async_suspend(&pdev->dev); > adap->owner = THIS_MODULE; > adap->class = I2C_CLASS_DEPRECATED; > ACPI_COMPANION_SET(&adap->dev, ACPI_COMPANION(&pdev->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.
-- Jarkko
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