| Message ID | 1461314971-5944-1-git-send-email-jszhang@marvell.com |
|---|---|
| State | New |
| Headers | show |
Hi On 04/22/2016 11:49 AM, Jisheng Zhang wrote: > If i2c_dw_probe() fails, we should disable and unprepare the clock, > otherwise the clock enable and prepare is left unbalanced. > > In dw_i2c_plat_remove(), we'd better to not rely on runtime PM to > disable and unprepare the clock since CONFIG_PM may be disabled when > configuring the kernel. So we explicitly disable and unprepare the > clock in dw_i2c_plat_remove() rather than implicitly rely on > pm_runtime_put_sync(). To keep the device usage count balanced, we > call pm_runtime_put_noidle() to decrease the usage count. > > Signed-off-by: Jisheng Zhang <jszhang@marvell.com> > --- > Since v3: > - use runtime PM rather than rpm in commit msg > - remove duplicated "(" in commit msg > > Since v2: > - s/clk/clock > - describe why use pm_runtime_put_noidle() > > Since v1: > - fix commit msg: "not rely on rpm" rather than "rely on rpm" > - call i2c_dw_plat_prepare_clk after pm_rumtime_disable() > drivers/i2c/busses/i2c-designware-platdrv.c | 16 ++++++++++------ > 1 file changed, 10 insertions(+), 6 deletions(-) > > diff --git a/drivers/i2c/busses/i2c-designware-platdrv.c b/drivers/i2c/busses/i2c-designware-platdrv.c > index d656657..a771781 100644 > --- a/drivers/i2c/busses/i2c-designware-platdrv.c > +++ b/drivers/i2c/busses/i2c-designware-platdrv.c > @@ -253,8 +253,11 @@ static int dw_i2c_plat_probe(struct platform_device *pdev) > } > > r = i2c_dw_probe(dev); > - if (r && !dev->pm_runtime_disabled) > - pm_runtime_disable(&pdev->dev); > + if (r) { > + if (!dev->pm_runtime_disabled) > + pm_runtime_disable(&pdev->dev); > + i2c_dw_plat_prepare_clk(dev, false); > + } > > return r; > } > @@ -264,15 +267,16 @@ static int dw_i2c_plat_remove(struct platform_device *pdev) > struct dw_i2c_dev *dev = platform_get_drvdata(pdev); > > pm_runtime_get_sync(&pdev->dev); > + pm_runtime_dont_use_autosuspend(&pdev->dev); > + if (!dev->pm_runtime_disabled) > + pm_runtime_disable(&pdev->dev); > + pm_runtime_put_noidle(&pdev->dev); > > i2c_del_adapter(&dev->adapter); > > i2c_dw_disable(dev); > > - pm_runtime_dont_use_autosuspend(&pdev->dev); > - pm_runtime_put_sync(&pdev->dev); > - if (!dev->pm_runtime_disabled) > - pm_runtime_disable(&pdev->dev); > + i2c_dw_plat_prepare_clk(dev, false); > This feels a bit an invasive change to me for unbalanced clock enable/disable and I noticed this changes semantics how drivers/acpi/acpi_lpss.c devices are shutdown when removing the driver. Although I didn't notice does it cause any regression. Before patch: 1. drivers/base/dd.c: __device_release_driver() - pm_runtime_get_sync() -> acpi_device_set_power(D0) acpi_lpss_restore_ctx() dw_i2c_plat_resume() 2. dw_i2c_plat_remove() - pm_runtime_dont_use_autosuspend() pm_runtime_put_sync() -> dw_i2c_plat_suspend() acpi_lpss_save_ctx() acpi_device_set_power(D3) 3. __device_release_driver() continue - dev->pm_domain->dismiss(dev) -> acpi_lpss_dismiss() ... -> acpi_device_set_power(D3) After patch: 1. drivers/base/dd.c: __device_release_driver() - pm_runtime_get_sync() -> acpi_device_set_power(D0) acpi_lpss_restore_ctx() dw_i2c_plat_resume() 2. dw_i2c_plat_remove() - pm_runtime_dont_use_autosuspend() pm_runtime_put_noidle() * no device suspending and acpi_lpss_save_ctx() 3. __device_release_driver() continue - dev->pm_domain->dismiss(dev) -> acpi_lpss_dismiss() ... -> acpi_device_set_power(D3) * powers down here So after patch there is no acpi_lpss_save_ctx() call but I don't see does it cause any issue here. Maybe it's better to track clock only. What you think Andy?
On Fri, 2016-04-22 at 16:59 +0300, Jarkko Nikula wrote: > Hi > > On 04/22/2016 11:49 AM, Jisheng Zhang wrote: > > > > If i2c_dw_probe() fails, we should disable and unprepare the clock, > > otherwise the clock enable and prepare is left unbalanced. > > > > In dw_i2c_plat_remove(), we'd better to not rely on runtime PM to > > disable and unprepare the clock since CONFIG_PM may be disabled when > > configuring the kernel. So we explicitly disable and unprepare the > > clock in dw_i2c_plat_remove() rather than implicitly rely on > > pm_runtime_put_sync(). To keep the device usage count balanced, we > > call pm_runtime_put_noidle() to decrease the usage count. > > > > Signed-off-by: Jisheng Zhang <jszhang@marvell.com> > > --- > > Since v3: > > - use runtime PM rather than rpm in commit msg > > - remove duplicated "(" in commit msg > > > > Since v2: > > - s/clk/clock > > - describe why use pm_runtime_put_noidle() > > > > Since v1: > > - fix commit msg: "not rely on rpm" rather than "rely on rpm" > > - call i2c_dw_plat_prepare_clk after pm_rumtime_disable() > > drivers/i2c/busses/i2c-designware-platdrv.c | 16 ++++++++++------ > > 1 file changed, 10 insertions(+), 6 deletions(-) > > > > diff --git a/drivers/i2c/busses/i2c-designware-platdrv.c > > b/drivers/i2c/busses/i2c-designware-platdrv.c > > index d656657..a771781 100644 > > --- a/drivers/i2c/busses/i2c-designware-platdrv.c > > +++ b/drivers/i2c/busses/i2c-designware-platdrv.c > > @@ -253,8 +253,11 @@ static int dw_i2c_plat_probe(struct > > platform_device *pdev) > > } > > > > r = i2c_dw_probe(dev); > > - if (r && !dev->pm_runtime_disabled) > > - pm_runtime_disable(&pdev->dev); > > + if (r) { > > + if (!dev->pm_runtime_disabled) > > + pm_runtime_disable(&pdev->dev); > > + i2c_dw_plat_prepare_clk(dev, false); > > + } > > > > return r; > > } > > @@ -264,15 +267,16 @@ static int dw_i2c_plat_remove(struct > > platform_device *pdev) > > struct dw_i2c_dev *dev = platform_get_drvdata(pdev); > > > > pm_runtime_get_sync(&pdev->dev); > > + pm_runtime_dont_use_autosuspend(&pdev->dev); > > + if (!dev->pm_runtime_disabled) > > + pm_runtime_disable(&pdev->dev); > > + pm_runtime_put_noidle(&pdev->dev); > > > > i2c_del_adapter(&dev->adapter); > > > > i2c_dw_disable(dev); > > > > - pm_runtime_dont_use_autosuspend(&pdev->dev); > > - pm_runtime_put_sync(&pdev->dev); > > - if (!dev->pm_runtime_disabled) > > - pm_runtime_disable(&pdev->dev); > > + i2c_dw_plat_prepare_clk(dev, false); > > > This feels a bit an invasive change to me for unbalanced clock > enable/disable and I noticed this changes semantics how > drivers/acpi/acpi_lpss.c devices are shutdown when removing the > driver. > Although I didn't notice does it cause any regression. > > Before patch: > 1. drivers/base/dd.c: __device_release_driver() > - pm_runtime_get_sync() > -> acpi_device_set_power(D0) > acpi_lpss_restore_ctx() > dw_i2c_plat_resume() > 2. dw_i2c_plat_remove() > - pm_runtime_dont_use_autosuspend() > pm_runtime_put_sync() > -> dw_i2c_plat_suspend() > acpi_lpss_save_ctx() > acpi_device_set_power(D3) > 3. __device_release_driver() continue > - dev->pm_domain->dismiss(dev) > -> acpi_lpss_dismiss() ... -> acpi_device_set_power(D3) > > After patch: > 1. drivers/base/dd.c: __device_release_driver() > - pm_runtime_get_sync() > -> acpi_device_set_power(D0) > acpi_lpss_restore_ctx() > dw_i2c_plat_resume() > 2. dw_i2c_plat_remove() > - pm_runtime_dont_use_autosuspend() > pm_runtime_put_noidle() > * no device suspending and acpi_lpss_save_ctx() > 3. __device_release_driver() continue > - dev->pm_domain->dismiss(dev) > -> acpi_lpss_dismiss() ... -> acpi_device_set_power(D3) > * powers down here > > So after patch there is no acpi_lpss_save_ctx() call but I don't see > does it cause any issue here. Maybe it's better to track clock only. > What you think Andy? Now it looks like two fixes in one patch. From the commit message I didn't get the relation between change runtime PM call (one to the other) and clock (un)preparation.
Dear Andy On Mon, 25 Apr 2016 12:07:15 +0300 Andy Shevchenko wrote: > On Fri, 2016-04-22 at 16:59 +0300, Jarkko Nikula wrote: > > Hi > > > > On 04/22/2016 11:49 AM, Jisheng Zhang wrote: > > > > > > If i2c_dw_probe() fails, we should disable and unprepare the clock, > > > otherwise the clock enable and prepare is left unbalanced. > > > > > > In dw_i2c_plat_remove(), we'd better to not rely on runtime PM to > > > disable and unprepare the clock since CONFIG_PM may be disabled when > > > configuring the kernel. So we explicitly disable and unprepare the > > > clock in dw_i2c_plat_remove() rather than implicitly rely on > > > pm_runtime_put_sync(). To keep the device usage count balanced, we > > > call pm_runtime_put_noidle() to decrease the usage count. > > > > > > Signed-off-by: Jisheng Zhang <jszhang@marvell.com> > > > --- > > > Since v3: > > > - use runtime PM rather than rpm in commit msg > > > - remove duplicated "(" in commit msg > > > > > > Since v2: > > > - s/clk/clock > > > - describe why use pm_runtime_put_noidle() > > > > > > Since v1: > > > - fix commit msg: "not rely on rpm" rather than "rely on rpm" > > > - call i2c_dw_plat_prepare_clk after pm_rumtime_disable() > > > drivers/i2c/busses/i2c-designware-platdrv.c | 16 ++++++++++------ > > > 1 file changed, 10 insertions(+), 6 deletions(-) > > > > > > diff --git a/drivers/i2c/busses/i2c-designware-platdrv.c > > > b/drivers/i2c/busses/i2c-designware-platdrv.c > > > index d656657..a771781 100644 > > > --- a/drivers/i2c/busses/i2c-designware-platdrv.c > > > +++ b/drivers/i2c/busses/i2c-designware-platdrv.c > > > @@ -253,8 +253,11 @@ static int dw_i2c_plat_probe(struct > > > platform_device *pdev) > > > } > > > > > > r = i2c_dw_probe(dev); > > > - if (r && !dev->pm_runtime_disabled) > > > - pm_runtime_disable(&pdev->dev); > > > + if (r) { > > > + if (!dev->pm_runtime_disabled) > > > + pm_runtime_disable(&pdev->dev); > > > + i2c_dw_plat_prepare_clk(dev, false); > > > + } > > > > > > return r; > > > } > > > @@ -264,15 +267,16 @@ static int dw_i2c_plat_remove(struct > > > platform_device *pdev) > > > struct dw_i2c_dev *dev = platform_get_drvdata(pdev); > > > > > > pm_runtime_get_sync(&pdev->dev); > > > + pm_runtime_dont_use_autosuspend(&pdev->dev); > > > + if (!dev->pm_runtime_disabled) > > > + pm_runtime_disable(&pdev->dev); > > > + pm_runtime_put_noidle(&pdev->dev); > > > > > > i2c_del_adapter(&dev->adapter); > > > > > > i2c_dw_disable(dev); > > > > > > - pm_runtime_dont_use_autosuspend(&pdev->dev); > > > - pm_runtime_put_sync(&pdev->dev); > > > - if (!dev->pm_runtime_disabled) > > > - pm_runtime_disable(&pdev->dev); > > > + i2c_dw_plat_prepare_clk(dev, false); > > > > > This feels a bit an invasive change to me for unbalanced clock > > enable/disable and I noticed this changes semantics how > > drivers/acpi/acpi_lpss.c devices are shutdown when removing the > > driver. > > Although I didn't notice does it cause any regression. > > > > Before patch: > > 1. drivers/base/dd.c: __device_release_driver() > > - pm_runtime_get_sync() > > -> acpi_device_set_power(D0) > > acpi_lpss_restore_ctx() > > dw_i2c_plat_resume() > > 2. dw_i2c_plat_remove() > > - pm_runtime_dont_use_autosuspend() > > pm_runtime_put_sync() > > -> dw_i2c_plat_suspend() > > acpi_lpss_save_ctx() > > acpi_device_set_power(D3) > > 3. __device_release_driver() continue > > - dev->pm_domain->dismiss(dev) > > -> acpi_lpss_dismiss() ... -> acpi_device_set_power(D3) > > > > After patch: > > 1. drivers/base/dd.c: __device_release_driver() > > - pm_runtime_get_sync() > > -> acpi_device_set_power(D0) > > acpi_lpss_restore_ctx() > > dw_i2c_plat_resume() > > 2. dw_i2c_plat_remove() > > - pm_runtime_dont_use_autosuspend() > > pm_runtime_put_noidle() > > * no device suspending and acpi_lpss_save_ctx() > > 3. __device_release_driver() continue > > - dev->pm_domain->dismiss(dev) > > -> acpi_lpss_dismiss() ... -> acpi_device_set_power(D3) > > * powers down here > > > > So after patch there is no acpi_lpss_save_ctx() call but I don't see > > does it cause any issue here. Maybe it's better to track clock only. > > What you think Andy? > > Now it looks like two fixes in one patch. From the commit message I > didn't get the relation between change runtime PM call (one to the > other) and clock (un)preparation. > I'm not sure I got your points. There are two unbalanced clk enable and prepare issues before the patch: one is in the i2c_dw_probe() failure path. another is in the remove path when CONFIG_PM is disabled. The patch addresses this unbalance. Thanks, Jisheng -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" 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-designware-platdrv.c b/drivers/i2c/busses/i2c-designware-platdrv.c index d656657..a771781 100644 --- a/drivers/i2c/busses/i2c-designware-platdrv.c +++ b/drivers/i2c/busses/i2c-designware-platdrv.c @@ -253,8 +253,11 @@ static int dw_i2c_plat_probe(struct platform_device *pdev) } r = i2c_dw_probe(dev); - if (r && !dev->pm_runtime_disabled) - pm_runtime_disable(&pdev->dev); + if (r) { + if (!dev->pm_runtime_disabled) + pm_runtime_disable(&pdev->dev); + i2c_dw_plat_prepare_clk(dev, false); + } return r; } @@ -264,15 +267,16 @@ static int dw_i2c_plat_remove(struct platform_device *pdev) struct dw_i2c_dev *dev = platform_get_drvdata(pdev); pm_runtime_get_sync(&pdev->dev); + pm_runtime_dont_use_autosuspend(&pdev->dev); + if (!dev->pm_runtime_disabled) + pm_runtime_disable(&pdev->dev); + pm_runtime_put_noidle(&pdev->dev); i2c_del_adapter(&dev->adapter); i2c_dw_disable(dev); - pm_runtime_dont_use_autosuspend(&pdev->dev); - pm_runtime_put_sync(&pdev->dev); - if (!dev->pm_runtime_disabled) - pm_runtime_disable(&pdev->dev); + i2c_dw_plat_prepare_clk(dev, false); return 0; }
If i2c_dw_probe() fails, we should disable and unprepare the clock, otherwise the clock enable and prepare is left unbalanced. In dw_i2c_plat_remove(), we'd better to not rely on runtime PM to disable and unprepare the clock since CONFIG_PM may be disabled when configuring the kernel. So we explicitly disable and unprepare the clock in dw_i2c_plat_remove() rather than implicitly rely on pm_runtime_put_sync(). To keep the device usage count balanced, we call pm_runtime_put_noidle() to decrease the usage count. Signed-off-by: Jisheng Zhang <jszhang@marvell.com> --- Since v3: - use runtime PM rather than rpm in commit msg - remove duplicated "(" in commit msg Since v2: - s/clk/clock - describe why use pm_runtime_put_noidle() Since v1: - fix commit msg: "not rely on rpm" rather than "rely on rpm" - call i2c_dw_plat_prepare_clk after pm_rumtime_disable() drivers/i2c/busses/i2c-designware-platdrv.c | 16 ++++++++++------ 1 file changed, 10 insertions(+), 6 deletions(-)