| Message ID | 1393671371-2398-6-git-send-email-ulf.hansson@linaro.org |
|---|---|
| State | Accepted |
| Commit | 9219982bc64a41ec7745668b06f86e97b498e10a |
| Headers | show |
On 1 March 2014 11:56, Ulf Hansson <ulf.hansson@linaro.org> wrote: > For !CONFIG_PM_RUNTIME, the device were never put back into active > state while resuming. > > For CONFIG_PM_RUNTIME, we blindly trusted the device to be inactive > while we were about to handle it at suspend late, which is just too > optimistic. > > Even if the driver uses pm_runtime_put_sync() after each tranfer to > return it's runtime PM resources, there are no guarantees this will > actually mean the device will inactivated. The reason is that the PM > core will prevent runtime suspend during system suspend, and thus when > a transfer occurs during the early phases of system suspend the device > will be kept active after the transfer. > > To handle both issues above, use pm_runtime_force_suspend|resume() from > the system suspend|resume callbacks. > > Cc: Alessandro Rubini <rubini@unipv.it> > Cc: Linus Walleij <linus.walleij@linaro.org> > Cc: Wolfram Sang <wsa@the-dreams.de> > Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> Hi Wolfram, The pm-drivers branch of the linux-pm.git, contains the helper functions this patch depends on. If you decide to pull that branch to your tree, to be able to apply this patch, please let me know. Otherwise I will repost this patch once 3.15 rc1 is available. Kind regards Ulf Hansson > --- > drivers/i2c/busses/i2c-nomadik.c | 14 +++++++------- > 1 file changed, 7 insertions(+), 7 deletions(-) > > diff --git a/drivers/i2c/busses/i2c-nomadik.c b/drivers/i2c/busses/i2c-nomadik.c > index 8082f5c..519f5b8 100644 > --- a/drivers/i2c/busses/i2c-nomadik.c > +++ b/drivers/i2c/busses/i2c-nomadik.c > @@ -879,19 +879,19 @@ static irqreturn_t i2c_irq_handler(int irq, void *arg) > #ifdef CONFIG_PM_SLEEP > static int nmk_i2c_suspend_late(struct device *dev) > { > - pinctrl_pm_select_sleep_state(dev); > + int ret; > > + ret = pm_runtime_force_suspend(dev); > + if (ret) > + return ret; > + > + pinctrl_pm_select_sleep_state(dev); > return 0; > } > > static int nmk_i2c_resume_early(struct device *dev) > { > - /* First go to the default state */ > - pinctrl_pm_select_default_state(dev); > - /* Then let's idle the pins until the next transfer happens */ > - pinctrl_pm_select_idle_state(dev); > - > - return 0; > + return pm_runtime_force_resume(dev); > } > #endif > > -- > 1.7.9.5 > -- To unsubscribe from this list: send the line "unsubscribe linux-pm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/i2c/busses/i2c-nomadik.c b/drivers/i2c/busses/i2c-nomadik.c index 8082f5c..519f5b8 100644 --- a/drivers/i2c/busses/i2c-nomadik.c +++ b/drivers/i2c/busses/i2c-nomadik.c @@ -879,19 +879,19 @@ static irqreturn_t i2c_irq_handler(int irq, void *arg) #ifdef CONFIG_PM_SLEEP static int nmk_i2c_suspend_late(struct device *dev) { - pinctrl_pm_select_sleep_state(dev); + int ret; + ret = pm_runtime_force_suspend(dev); + if (ret) + return ret; + + pinctrl_pm_select_sleep_state(dev); return 0; } static int nmk_i2c_resume_early(struct device *dev) { - /* First go to the default state */ - pinctrl_pm_select_default_state(dev); - /* Then let's idle the pins until the next transfer happens */ - pinctrl_pm_select_idle_state(dev); - - return 0; + return pm_runtime_force_resume(dev); } #endif
For !CONFIG_PM_RUNTIME, the device were never put back into active state while resuming. For CONFIG_PM_RUNTIME, we blindly trusted the device to be inactive while we were about to handle it at suspend late, which is just too optimistic. Even if the driver uses pm_runtime_put_sync() after each tranfer to return it's runtime PM resources, there are no guarantees this will actually mean the device will inactivated. The reason is that the PM core will prevent runtime suspend during system suspend, and thus when a transfer occurs during the early phases of system suspend the device will be kept active after the transfer. To handle both issues above, use pm_runtime_force_suspend|resume() from the system suspend|resume callbacks. Cc: Alessandro Rubini <rubini@unipv.it> Cc: Linus Walleij <linus.walleij@linaro.org> Cc: Wolfram Sang <wsa@the-dreams.de> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> --- drivers/i2c/busses/i2c-nomadik.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-)