| Message ID | 20191213134417.222720-1-thierry.reding@gmail.com |
|---|---|
| State | Deferred |
| Headers | show |
| Series | i2c: tegra: Restore pinmux on system resume | expand |
Could this just be pm_runtime_force_suspend and pm_runtime_force_resume? Mikko On 13.12.2019 15.44, Thierry Reding wrote: > From: Thierry Reding <treding@nvidia.com> > > Depending on the board design, the I2C controllers found on Tegra SoCs > may require pinmuxing in order to function. This is done as part of the > driver's runtime suspend/resume operations. However, the PM core does > not allow devices to go into runtime suspend during system sleep to > avoid potential races with the suspend/resume of their parents. > > As a result of this, when Tegra SoCs resume from system suspend, their > I2C controllers may have lost the pinmux state in hardware, whereas the > pinctrl subsystem is not aware of this. To fix this, make sure that if > the I2C controller is not runtime suspended, the runtime suspend code is > still executed in order to disable the module clock (which we don't need > to be enabled during sleep) and set the pinmux to the idle state. > > Conversely, make sure that the I2C controller is properly resumed when > waking up from sleep so that pinmux settings are properly restored. > > This fixes a bug seen with DDC transactions to an HDMI monitor timing > out when resuming from system suspend. > > Signed-off-by: Thierry Reding <treding@nvidia.com> > --- > drivers/i2c/busses/i2c-tegra.c | 14 ++++++++++---- > 1 file changed, 10 insertions(+), 4 deletions(-) > > diff --git a/drivers/i2c/busses/i2c-tegra.c b/drivers/i2c/busses/i2c-tegra.c > index a98bf31d0e5c..dae2a3d7b512 100644 > --- a/drivers/i2c/busses/i2c-tegra.c > +++ b/drivers/i2c/busses/i2c-tegra.c > @@ -1710,10 +1710,14 @@ static int tegra_i2c_remove(struct platform_device *pdev) > static int __maybe_unused tegra_i2c_suspend(struct device *dev) > { > struct tegra_i2c_dev *i2c_dev = dev_get_drvdata(dev); > + int err = 0; > > i2c_mark_adapter_suspended(&i2c_dev->adapter); > > - return 0; > + if (!pm_runtime_status_suspended(dev)) > + err = tegra_i2c_runtime_suspend(dev); > + > + return err; > } > > static int __maybe_unused tegra_i2c_resume(struct device *dev) > @@ -1729,9 +1733,11 @@ static int __maybe_unused tegra_i2c_resume(struct device *dev) > if (err) > return err; > > - err = tegra_i2c_runtime_suspend(dev); > - if (err) > - return err; > + if (pm_runtime_status_suspended(dev)) { > + err = tegra_i2c_runtime_suspend(dev); > + if (err) > + return err; > + } > > i2c_mark_adapter_resumed(&i2c_dev->adapter); > >
Oh, I guess that option was already discussed =) Sorry, Mikko On 13.12.2019 16.03, Mikko Perttunen wrote: > Could this just be pm_runtime_force_suspend and pm_runtime_force_resume? > > Mikko > > On 13.12.2019 15.44, Thierry Reding wrote: >> From: Thierry Reding <treding@nvidia.com> >> >> Depending on the board design, the I2C controllers found on Tegra SoCs >> may require pinmuxing in order to function. This is done as part of the >> driver's runtime suspend/resume operations. However, the PM core does >> not allow devices to go into runtime suspend during system sleep to >> avoid potential races with the suspend/resume of their parents. >> >> As a result of this, when Tegra SoCs resume from system suspend, their >> I2C controllers may have lost the pinmux state in hardware, whereas the >> pinctrl subsystem is not aware of this. To fix this, make sure that if >> the I2C controller is not runtime suspended, the runtime suspend code is >> still executed in order to disable the module clock (which we don't need >> to be enabled during sleep) and set the pinmux to the idle state. >> >> Conversely, make sure that the I2C controller is properly resumed when >> waking up from sleep so that pinmux settings are properly restored. >> >> This fixes a bug seen with DDC transactions to an HDMI monitor timing >> out when resuming from system suspend. >> >> Signed-off-by: Thierry Reding <treding@nvidia.com> >> --- >> drivers/i2c/busses/i2c-tegra.c | 14 ++++++++++---- >> 1 file changed, 10 insertions(+), 4 deletions(-) >> >> diff --git a/drivers/i2c/busses/i2c-tegra.c >> b/drivers/i2c/busses/i2c-tegra.c >> index a98bf31d0e5c..dae2a3d7b512 100644 >> --- a/drivers/i2c/busses/i2c-tegra.c >> +++ b/drivers/i2c/busses/i2c-tegra.c >> @@ -1710,10 +1710,14 @@ static int tegra_i2c_remove(struct >> platform_device *pdev) >> static int __maybe_unused tegra_i2c_suspend(struct device *dev) >> { >> struct tegra_i2c_dev *i2c_dev = dev_get_drvdata(dev); >> + int err = 0; >> i2c_mark_adapter_suspended(&i2c_dev->adapter); >> - return 0; >> + if (!pm_runtime_status_suspended(dev)) >> + err = tegra_i2c_runtime_suspend(dev); >> + >> + return err; >> } >> static int __maybe_unused tegra_i2c_resume(struct device *dev) >> @@ -1729,9 +1733,11 @@ static int __maybe_unused >> tegra_i2c_resume(struct device *dev) >> if (err) >> return err; >> - err = tegra_i2c_runtime_suspend(dev); >> - if (err) >> - return err; >> + if (pm_runtime_status_suspended(dev)) { >> + err = tegra_i2c_runtime_suspend(dev); >> + if (err) >> + return err; >> + } >> i2c_mark_adapter_resumed(&i2c_dev->adapter); >>
On Fri, Dec 13, 2019 at 02:44:17PM +0100, Thierry Reding wrote: > From: Thierry Reding <treding@nvidia.com> > > Depending on the board design, the I2C controllers found on Tegra SoCs > may require pinmuxing in order to function. This is done as part of the > driver's runtime suspend/resume operations. However, the PM core does > not allow devices to go into runtime suspend during system sleep to > avoid potential races with the suspend/resume of their parents. > > As a result of this, when Tegra SoCs resume from system suspend, their > I2C controllers may have lost the pinmux state in hardware, whereas the > pinctrl subsystem is not aware of this. To fix this, make sure that if > the I2C controller is not runtime suspended, the runtime suspend code is > still executed in order to disable the module clock (which we don't need > to be enabled during sleep) and set the pinmux to the idle state. > > Conversely, make sure that the I2C controller is properly resumed when > waking up from sleep so that pinmux settings are properly restored. > > This fixes a bug seen with DDC transactions to an HDMI monitor timing > out when resuming from system suspend. > > Signed-off-by: Thierry Reding <treding@nvidia.com> Do we still need this after I applied "[PATCH v5 0/8] NVIDIA Tegra I2C driver fixes and improvements" ?
23.01.2020 14:19, Wolfram Sang пишет: > On Fri, Dec 13, 2019 at 02:44:17PM +0100, Thierry Reding wrote: >> From: Thierry Reding <treding@nvidia.com> >> >> Depending on the board design, the I2C controllers found on Tegra SoCs >> may require pinmuxing in order to function. This is done as part of the >> driver's runtime suspend/resume operations. However, the PM core does >> not allow devices to go into runtime suspend during system sleep to >> avoid potential races with the suspend/resume of their parents. >> >> As a result of this, when Tegra SoCs resume from system suspend, their >> I2C controllers may have lost the pinmux state in hardware, whereas the >> pinctrl subsystem is not aware of this. To fix this, make sure that if >> the I2C controller is not runtime suspended, the runtime suspend code is >> still executed in order to disable the module clock (which we don't need >> to be enabled during sleep) and set the pinmux to the idle state. >> >> Conversely, make sure that the I2C controller is properly resumed when >> waking up from sleep so that pinmux settings are properly restored. >> >> This fixes a bug seen with DDC transactions to an HDMI monitor timing >> out when resuming from system suspend. >> >> Signed-off-by: Thierry Reding <treding@nvidia.com> > > Do we still need this after I applied "[PATCH v5 0/8] NVIDIA Tegra I2C > driver fixes and improvements" ? > No, it shouldn't be needed.
diff --git a/drivers/i2c/busses/i2c-tegra.c b/drivers/i2c/busses/i2c-tegra.c index a98bf31d0e5c..dae2a3d7b512 100644 --- a/drivers/i2c/busses/i2c-tegra.c +++ b/drivers/i2c/busses/i2c-tegra.c @@ -1710,10 +1710,14 @@ static int tegra_i2c_remove(struct platform_device *pdev) static int __maybe_unused tegra_i2c_suspend(struct device *dev) { struct tegra_i2c_dev *i2c_dev = dev_get_drvdata(dev); + int err = 0; i2c_mark_adapter_suspended(&i2c_dev->adapter); - return 0; + if (!pm_runtime_status_suspended(dev)) + err = tegra_i2c_runtime_suspend(dev); + + return err; } static int __maybe_unused tegra_i2c_resume(struct device *dev) @@ -1729,9 +1733,11 @@ static int __maybe_unused tegra_i2c_resume(struct device *dev) if (err) return err; - err = tegra_i2c_runtime_suspend(dev); - if (err) - return err; + if (pm_runtime_status_suspended(dev)) { + err = tegra_i2c_runtime_suspend(dev); + if (err) + return err; + } i2c_mark_adapter_resumed(&i2c_dev->adapter);