Message ID | 1490844377-32182-1-git-send-email-john.stultz@linaro.org |
---|---|
State | Superseded |
Headers | show |
Hi On 03/30/2017 06:26 AM, John Stultz wrote: > On my HiKey board, I'm seeing clk warnings on suspend/resume, > which seem to be caused by runtime pm suspending the device, > then the same suspend hook being called again on suspend time. > > This patch fixes this by setting the SYSTEM_SLEEP_PM_OPS to > using pm_runtime_force_suspend and pm_runtime_force_resume. > > Cc: Jarkko Nikula <jarkko.nikula@linux.intel.com> > Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> > Cc: Mika Westerberg <mika.westerberg@linux.intel.com> > Cc: Wolfram Sang <wsa@the-dreams.de> > Cc: linux-i2c@vger.kernel.org > Suggested-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> > Signed-off-by: John Stultz <john.stultz@linaro.org> > --- > v2: Switch to suggested fix by Jarkko. > --- > drivers/i2c/busses/i2c-designware-platdrv.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/i2c/busses/i2c-designware-platdrv.c b/drivers/i2c/busses/i2c-designware-platdrv.c > index 79c4b4e..286447c 100644 > --- a/drivers/i2c/busses/i2c-designware-platdrv.c > +++ b/drivers/i2c/busses/i2c-designware-platdrv.c > @@ -382,7 +382,7 @@ static int dw_i2c_plat_resume(struct device *dev) > static const struct dev_pm_ops dw_i2c_dev_pm_ops = { > .prepare = dw_i2c_plat_prepare, > .complete = dw_i2c_plat_complete, > - SET_SYSTEM_SLEEP_PM_OPS(dw_i2c_plat_suspend, dw_i2c_plat_resume) > + SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend, pm_runtime_force_resume) > SET_RUNTIME_PM_OPS(dw_i2c_plat_suspend, dw_i2c_plat_resume, NULL) We cannot do this since it will break our platforms that use the drivers/acpi/acpi_lpss.c power domain. Reason why it fails the pm_runtime_force_suspend() forces acpi_lpss to power down too early before suspend_late state where context is expected to be saved during system suspend. acpi_lpss.c power domain .suspend = acpi_subsys_suspend -> pm_runtime_resume -> acpi_lpss_runtime_resume -> pm_generic_runtime_resume -> dw_i2c_plat_resume -> pm_generic_suspend -> pm_runtime_force_suspend -> goes through __rpm_get_callback which selects domain ops -> acpi_lpss_runtime_suspend (context save + power down) -> pm_generic_runtime_suspend -> dw_i2c_plat_suspend ... .suspend_late = acpi_lpss_suspend_late -> acpi_lpss is already power gated here due acpi_lpss_runtime_suspend() done during suspend phase and context save will save just 0xFFs and resume restores wrong context. I managed to found a use case where I'm able to trigger dw_i2c_plat_suspend() callback twice during suspend. Quite deep dive to PM core, lot of debugging and end result is a trivial patch that just checks is i2c-designware runtime suspended in its suspend/resume callbacks... This feels somewhat boilerplate and I figured also an alternative solution to PM core. I just sent that patch out and I Cc'ed both you and Rafael so he can comment is this the right thing to do in driver or should it be fixed in the PM core.
diff --git a/drivers/i2c/busses/i2c-designware-platdrv.c b/drivers/i2c/busses/i2c-designware-platdrv.c index 79c4b4e..286447c 100644 --- a/drivers/i2c/busses/i2c-designware-platdrv.c +++ b/drivers/i2c/busses/i2c-designware-platdrv.c @@ -382,7 +382,7 @@ static int dw_i2c_plat_resume(struct device *dev) static const struct dev_pm_ops dw_i2c_dev_pm_ops = { .prepare = dw_i2c_plat_prepare, .complete = dw_i2c_plat_complete, - SET_SYSTEM_SLEEP_PM_OPS(dw_i2c_plat_suspend, dw_i2c_plat_resume) + SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend, pm_runtime_force_resume) SET_RUNTIME_PM_OPS(dw_i2c_plat_suspend, dw_i2c_plat_resume, NULL) };
On my HiKey board, I'm seeing clk warnings on suspend/resume, which seem to be caused by runtime pm suspending the device, then the same suspend hook being called again on suspend time. This patch fixes this by setting the SYSTEM_SLEEP_PM_OPS to using pm_runtime_force_suspend and pm_runtime_force_resume. Cc: Jarkko Nikula <jarkko.nikula@linux.intel.com> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Mika Westerberg <mika.westerberg@linux.intel.com> Cc: Wolfram Sang <wsa@the-dreams.de> Cc: linux-i2c@vger.kernel.org Suggested-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> Signed-off-by: John Stultz <john.stultz@linaro.org> --- v2: Switch to suggested fix by Jarkko. --- drivers/i2c/busses/i2c-designware-platdrv.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)