On 1/5/2016 4:53 PM, 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 = &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. Because of long leave, so sorry for late reply. Your proposal is right. I have submitted a new patch according to your comments - "[PATCH v2] i2c/designware: enable i2c controller to suspend/resume asynchronously". Thanks, Zhonghui -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
