On 29 August 2017 at 12:29, Johannes Stezenbach <js@xxxxxxxxx> wrote: > Hi, > > On Tue, Aug 29, 2017 at 02:18:13AM +0200, Rafael J. Wysocki wrote: >> On Wednesday, August 23, 2017 4:42:00 PM CEST Ulf Hansson wrote: >> > The i2c designware platform driver, drivers/i2c/busses/i2c-designware-platdrv.c, >> > isn't well optimized for system sleep. >> > >> > What makes this driver particularly interesting is because it's a cross-SoC >> > driver, which sometimes means there is an ACPI PM domain attached to the i2c >> > device and sometimes not. The driver is being used on both x86 and ARM. > ... >> Basically, the point is to allow i2c-designware-platdrv to point its late >> suspend and early resume callbacks, respectively, to pm_runtime_force_suspend() >> and pm_runtime_force_resume() which then will do the right thing regardless of >> whether or not the device is runtime suspended when system suspend starts. > > I'd like to point out a comment added by Hans de Goede in > https://bugzilla.kernel.org/show_bug.cgi?id=193891#c99 > > The D0 / D3 methods of some devices use ACPI OpRegions on the PMIC which is > attached to I2C7, these methods get executed by acpi_dev_suspend_late / > acpi_dev_resume_early. Since the i2c-designware driver uses regular suspend / > resume callbacks it is already suspended at the time those calls happen, > leading to a device-suspend error and the system not suspending at all. Yes, that's why I moved those operation to be managed at the ->suspend_late() in my series, and at the same time prevent the direct_complete patch from executed for this device. > > It's the reason for the Cherrytrail I2C7 special treatment in > i2c-designware-platdrv.c and pm_disabled = true in i2c-designware-baytrail.c, > however pm_disabled seems to be a problem for S0ix support. > To solve it, i2c-designware-platdrv needs to suspend after all > devices using ACPI OpRegions for suspend. > > > Johannes Did you try out my series (v2) if that could fix this problem in a more flexible manner? In other words, is it fine if the device remains runtime PM enabled during the entire device_suspend() phase, and also not being suspended until ->suspend_late()? Kind regards Uffe
