[v1] clk: imx95-blk-ctl: Fix runtime PM issues

[PATCH 2/2] clk: imx95-blk-ctl: Save/restore registers when RPM routines are called

Posted by Laurentiu Palcu 6 months, 2 weeks ago

If runtime PM is used for the clock providers and they're part of a
power domain, then the power domain supply will be cut off when runtime
suspended. That means all BLK CTL registers belonging to that power
domain will be reset. Save the registers, then, before entering suspend
and restore them in resume.

Also, fix the suspend/resume routines and make sure we disable/enable
the clock correctly.

Signed-off-by: Laurentiu Palcu <laurentiu.palcu@oss.nxp.com>
---
 drivers/clk/imx/clk-imx95-blk-ctl.c | 33 ++++++++++++++++++-----------
 1 file changed, 21 insertions(+), 12 deletions(-)

diff --git a/drivers/clk/imx/clk-imx95-blk-ctl.c b/drivers/clk/imx/clk-imx95-blk-ctl.c
index c72debaf3a60b..56bed44719954 100644
--- a/drivers/clk/imx/clk-imx95-blk-ctl.c
+++ b/drivers/clk/imx/clk-imx95-blk-ctl.c
@@ -453,15 +453,24 @@ static int imx95_bc_runtime_suspend(struct device *dev)
 {
 	struct imx95_blk_ctl *bc = dev_get_drvdata(dev);
 
+	bc->clk_reg_restore = readl(bc->base + bc->pdata->clk_reg_offset);
 	clk_disable_unprepare(bc->clk_apb);
+
 	return 0;
 }
 
 static int imx95_bc_runtime_resume(struct device *dev)
 {
 	struct imx95_blk_ctl *bc = dev_get_drvdata(dev);
+	int ret;
 
-	return clk_prepare_enable(bc->clk_apb);
+	ret = clk_prepare_enable(bc->clk_apb);
+	if (ret)
+		return ret;
+
+	writel(bc->clk_reg_restore, bc->base + bc->pdata->clk_reg_offset);
+
+	return 0;
 }
 #endif
 
@@ -469,17 +478,12 @@ static int imx95_bc_runtime_resume(struct device *dev)
 static int imx95_bc_suspend(struct device *dev)
 {
 	struct imx95_blk_ctl *bc = dev_get_drvdata(dev);
-	int ret;
 
-	if (bc->pdata->rpm_enabled) {
-		ret = pm_runtime_get_sync(bc->dev);
-		if (ret < 0) {
-			pm_runtime_put_noidle(bc->dev);
-			return ret;
-		}
-	}
+	if (pm_runtime_suspended(dev))
+		return 0;
 
 	bc->clk_reg_restore = readl(bc->base + bc->pdata->clk_reg_offset);
+	clk_disable_unprepare(bc->clk_apb);
 
 	return 0;
 }
@@ -487,11 +491,16 @@ static int imx95_bc_suspend(struct device *dev)
 static int imx95_bc_resume(struct device *dev)
 {
 	struct imx95_blk_ctl *bc = dev_get_drvdata(dev);
+	int ret;
 
-	writel(bc->clk_reg_restore, bc->base + bc->pdata->clk_reg_offset);
+	if (pm_runtime_suspended(dev))
+		return 0;
 
-	if (bc->pdata->rpm_enabled)
-		pm_runtime_put(bc->dev);
+	ret = clk_prepare_enable(bc->clk_apb);
+	if (ret)
+		return ret;
+
+	writel(bc->clk_reg_restore, bc->base + bc->pdata->clk_reg_offset);
 
 	return 0;
 }
-- 
2.46.1

Re: [PATCH 2/2] clk: imx95-blk-ctl: Save/restore registers when RPM routines are called

Posted by Frank Li 6 months, 2 weeks ago

On Wed, Jul 30, 2025 at 03:59:31PM +0300, Laurentiu Palcu wrote:
> If runtime PM is used for the clock providers and they're part of a
> power domain, then the power domain supply will be cut off when runtime
> suspended. That means all BLK CTL registers belonging to that power
> domain will be reset. Save the registers, then, before entering suspend
> and restore them in resume.

Save the registers before entering suspend, then restore them in resume.

>
> Also, fix the suspend/resume routines and make sure we disable/enable
> the clock correctly.

Check runtime pm status in suspend/resume routines to make sure
disable/enable clock correctly.

>
> Signed-off-by: Laurentiu Palcu <laurentiu.palcu@oss.nxp.com>
> ---
>  drivers/clk/imx/clk-imx95-blk-ctl.c | 33 ++++++++++++++++++-----------
>  1 file changed, 21 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/clk/imx/clk-imx95-blk-ctl.c b/drivers/clk/imx/clk-imx95-blk-ctl.c
> index c72debaf3a60b..56bed44719954 100644
> --- a/drivers/clk/imx/clk-imx95-blk-ctl.c
> +++ b/drivers/clk/imx/clk-imx95-blk-ctl.c
> @@ -453,15 +453,24 @@ static int imx95_bc_runtime_suspend(struct device *dev)
>  {
>  	struct imx95_blk_ctl *bc = dev_get_drvdata(dev);
>
> +	bc->clk_reg_restore = readl(bc->base + bc->pdata->clk_reg_offset);
>  	clk_disable_unprepare(bc->clk_apb);
> +
>  	return 0;
>  }
>
>  static int imx95_bc_runtime_resume(struct device *dev)
>  {
>  	struct imx95_blk_ctl *bc = dev_get_drvdata(dev);
> +	int ret;
>
> -	return clk_prepare_enable(bc->clk_apb);
> +	ret = clk_prepare_enable(bc->clk_apb);
> +	if (ret)
> +		return ret;
> +
> +	writel(bc->clk_reg_restore, bc->base + bc->pdata->clk_reg_offset);
> +
> +	return 0;
>  }
>  #endif
>
> @@ -469,17 +478,12 @@ static int imx95_bc_runtime_resume(struct device *dev)
>  static int imx95_bc_suspend(struct device *dev)
>  {
>  	struct imx95_blk_ctl *bc = dev_get_drvdata(dev);
> -	int ret;
>
> -	if (bc->pdata->rpm_enabled) {
> -		ret = pm_runtime_get_sync(bc->dev);
> -		if (ret < 0) {
> -			pm_runtime_put_noidle(bc->dev);
> -			return ret;
> -		}
> -	}
> +	if (pm_runtime_suspended(dev))
> +		return 0;
>
>  	bc->clk_reg_restore = readl(bc->base + bc->pdata->clk_reg_offset);
> +	clk_disable_unprepare(bc->clk_apb);
>
>  	return 0;
>  }
> @@ -487,11 +491,16 @@ static int imx95_bc_suspend(struct device *dev)
>  static int imx95_bc_resume(struct device *dev)
>  {
>  	struct imx95_blk_ctl *bc = dev_get_drvdata(dev);
> +	int ret;
>
> -	writel(bc->clk_reg_restore, bc->base + bc->pdata->clk_reg_offset);
> +	if (pm_runtime_suspended(dev))
> +		return 0;
>
> -	if (bc->pdata->rpm_enabled)
> -		pm_runtime_put(bc->dev);
> +	ret = clk_prepare_enable(bc->clk_apb);
> +	if (ret)
> +		return ret;
> +
> +	writel(bc->clk_reg_restore, bc->base + bc->pdata->clk_reg_offset);
>
>  	return 0;
>  }
> --
> 2.46.1
>

Re: [PATCH 2/2] clk: imx95-blk-ctl: Save/restore registers when RPM routines are called

Posted by Laurentiu Palcu 6 months, 1 week ago

Hi Frank,

On Wed, Jul 30, 2025 at 12:23:46PM -0400, Frank Li wrote:
> On Wed, Jul 30, 2025 at 03:59:31PM +0300, Laurentiu Palcu wrote:
> > If runtime PM is used for the clock providers and they're part of a
> > power domain, then the power domain supply will be cut off when runtime
> > suspended. That means all BLK CTL registers belonging to that power
> > domain will be reset. Save the registers, then, before entering suspend
> > and restore them in resume.
> 
> Save the registers before entering suspend, then restore them in resume.
> 
> >
> > Also, fix the suspend/resume routines and make sure we disable/enable
> > the clock correctly.
> 
> Check runtime pm status in suspend/resume routines to make sure
> disable/enable clock correctly.

I think the current commit message is clear enough already and follows
the guidelines. Obviously, someone else could rephrase it differently
but I'm pretty happy with it in its current state. TBH, your suggested
changes neither add new information nor correct any grammar or spelling
mistakes, so I don't see a strong point in changing the commit message.

Thanks,
Laurentiu

> 
> >
> > Signed-off-by: Laurentiu Palcu <laurentiu.palcu@oss.nxp.com>
> > ---
> >  drivers/clk/imx/clk-imx95-blk-ctl.c | 33 ++++++++++++++++++-----------
> >  1 file changed, 21 insertions(+), 12 deletions(-)
> >
> > diff --git a/drivers/clk/imx/clk-imx95-blk-ctl.c b/drivers/clk/imx/clk-imx95-blk-ctl.c
> > index c72debaf3a60b..56bed44719954 100644
> > --- a/drivers/clk/imx/clk-imx95-blk-ctl.c
> > +++ b/drivers/clk/imx/clk-imx95-blk-ctl.c
> > @@ -453,15 +453,24 @@ static int imx95_bc_runtime_suspend(struct device *dev)
> >  {
> >  	struct imx95_blk_ctl *bc = dev_get_drvdata(dev);
> >
> > +	bc->clk_reg_restore = readl(bc->base + bc->pdata->clk_reg_offset);
> >  	clk_disable_unprepare(bc->clk_apb);
> > +
> >  	return 0;
> >  }
> >
> >  static int imx95_bc_runtime_resume(struct device *dev)
> >  {
> >  	struct imx95_blk_ctl *bc = dev_get_drvdata(dev);
> > +	int ret;
> >
> > -	return clk_prepare_enable(bc->clk_apb);
> > +	ret = clk_prepare_enable(bc->clk_apb);
> > +	if (ret)
> > +		return ret;
> > +
> > +	writel(bc->clk_reg_restore, bc->base + bc->pdata->clk_reg_offset);
> > +
> > +	return 0;
> >  }
> >  #endif
> >
> > @@ -469,17 +478,12 @@ static int imx95_bc_runtime_resume(struct device *dev)
> >  static int imx95_bc_suspend(struct device *dev)
> >  {
> >  	struct imx95_blk_ctl *bc = dev_get_drvdata(dev);
> > -	int ret;
> >
> > -	if (bc->pdata->rpm_enabled) {
> > -		ret = pm_runtime_get_sync(bc->dev);
> > -		if (ret < 0) {
> > -			pm_runtime_put_noidle(bc->dev);
> > -			return ret;
> > -		}
> > -	}
> > +	if (pm_runtime_suspended(dev))
> > +		return 0;
> >
> >  	bc->clk_reg_restore = readl(bc->base + bc->pdata->clk_reg_offset);
> > +	clk_disable_unprepare(bc->clk_apb);
> >
> >  	return 0;
> >  }
> > @@ -487,11 +491,16 @@ static int imx95_bc_suspend(struct device *dev)
> >  static int imx95_bc_resume(struct device *dev)
> >  {
> >  	struct imx95_blk_ctl *bc = dev_get_drvdata(dev);
> > +	int ret;
> >
> > -	writel(bc->clk_reg_restore, bc->base + bc->pdata->clk_reg_offset);
> > +	if (pm_runtime_suspended(dev))
> > +		return 0;
> >
> > -	if (bc->pdata->rpm_enabled)
> > -		pm_runtime_put(bc->dev);
> > +	ret = clk_prepare_enable(bc->clk_apb);
> > +	if (ret)
> > +		return ret;
> > +
> > +	writel(bc->clk_reg_restore, bc->base + bc->pdata->clk_reg_offset);
> >
> >  	return 0;
> >  }
> > --
> > 2.46.1
> >

Re: [PATCH 2/2] clk: imx95-blk-ctl: Save/restore registers when RPM routines are called

Posted by Frank Li 6 months, 1 week ago

On Thu, Jul 31, 2025 at 10:31:25AM +0300, Laurentiu Palcu wrote:
> Hi Frank,
>
> On Wed, Jul 30, 2025 at 12:23:46PM -0400, Frank Li wrote:
> > On Wed, Jul 30, 2025 at 03:59:31PM +0300, Laurentiu Palcu wrote:
> > > If runtime PM is used for the clock providers and they're part of a
> > > power domain, then the power domain supply will be cut off when runtime
> > > suspended. That means all BLK CTL registers belonging to that power
> > > domain will be reset. Save the registers, then, before entering suspend
> > > and restore them in resume.
> >
> > Save the registers before entering suspend, then restore them in resume.
> >
> > >
> > > Also, fix the suspend/resume routines and make sure we disable/enable
> > > the clock correctly.
> >
> > Check runtime pm status in suspend/resume routines to make sure
> > disable/enable clock correctly.
>
> I think the current commit message is clear enough already and follows
> the guidelines. Obviously, someone else could rephrase it differently
> but I'm pretty happy with it in its current state. TBH, your suggested
> changes neither add new information nor correct any grammar or spelling
> mistakes, so I don't see a strong point in changing the commit message.

"fix the suspend/resume routines" have not carry much informaiton. Need
deescript as "do (what) in (where) to fix (what's problem).

Without check patch, No one understand what's means of

"fix the suspend/resume routines and make sure we disable/enable
the clock correctly."

Frank

>
> Thanks,
> Laurentiu
>
> >
> > >
> > > Signed-off-by: Laurentiu Palcu <laurentiu.palcu@oss.nxp.com>
> > > ---
> > >  drivers/clk/imx/clk-imx95-blk-ctl.c | 33 ++++++++++++++++++-----------
> > >  1 file changed, 21 insertions(+), 12 deletions(-)
> > >
> > > diff --git a/drivers/clk/imx/clk-imx95-blk-ctl.c b/drivers/clk/imx/clk-imx95-blk-ctl.c
> > > index c72debaf3a60b..56bed44719954 100644
> > > --- a/drivers/clk/imx/clk-imx95-blk-ctl.c
> > > +++ b/drivers/clk/imx/clk-imx95-blk-ctl.c
> > > @@ -453,15 +453,24 @@ static int imx95_bc_runtime_suspend(struct device *dev)
> > >  {
> > >  	struct imx95_blk_ctl *bc = dev_get_drvdata(dev);
> > >
> > > +	bc->clk_reg_restore = readl(bc->base + bc->pdata->clk_reg_offset);
> > >  	clk_disable_unprepare(bc->clk_apb);
> > > +
> > >  	return 0;
> > >  }
> > >
> > >  static int imx95_bc_runtime_resume(struct device *dev)
> > >  {
> > >  	struct imx95_blk_ctl *bc = dev_get_drvdata(dev);
> > > +	int ret;
> > >
> > > -	return clk_prepare_enable(bc->clk_apb);
> > > +	ret = clk_prepare_enable(bc->clk_apb);
> > > +	if (ret)
> > > +		return ret;
> > > +
> > > +	writel(bc->clk_reg_restore, bc->base + bc->pdata->clk_reg_offset);
> > > +
> > > +	return 0;
> > >  }
> > >  #endif
> > >
> > > @@ -469,17 +478,12 @@ static int imx95_bc_runtime_resume(struct device *dev)
> > >  static int imx95_bc_suspend(struct device *dev)
> > >  {
> > >  	struct imx95_blk_ctl *bc = dev_get_drvdata(dev);
> > > -	int ret;
> > >
> > > -	if (bc->pdata->rpm_enabled) {
> > > -		ret = pm_runtime_get_sync(bc->dev);
> > > -		if (ret < 0) {
> > > -			pm_runtime_put_noidle(bc->dev);
> > > -			return ret;
> > > -		}
> > > -	}
> > > +	if (pm_runtime_suspended(dev))
> > > +		return 0;
> > >
> > >  	bc->clk_reg_restore = readl(bc->base + bc->pdata->clk_reg_offset);
> > > +	clk_disable_unprepare(bc->clk_apb);
> > >
> > >  	return 0;
> > >  }
> > > @@ -487,11 +491,16 @@ static int imx95_bc_suspend(struct device *dev)
> > >  static int imx95_bc_resume(struct device *dev)
> > >  {
> > >  	struct imx95_blk_ctl *bc = dev_get_drvdata(dev);
> > > +	int ret;
> > >
> > > -	writel(bc->clk_reg_restore, bc->base + bc->pdata->clk_reg_offset);
> > > +	if (pm_runtime_suspended(dev))
> > > +		return 0;
> > >
> > > -	if (bc->pdata->rpm_enabled)
> > > -		pm_runtime_put(bc->dev);
> > > +	ret = clk_prepare_enable(bc->clk_apb);
> > > +	if (ret)
> > > +		return ret;
> > > +
> > > +	writel(bc->clk_reg_restore, bc->base + bc->pdata->clk_reg_offset);
> > >
> > >  	return 0;
> > >  }
> > > --
> > > 2.46.1
> > >

[PATCH 1/2] clk: imx95-blk-ctl: Save platform data in imx95_blk_ctl structure
[PATCH 2/2] clk: imx95-blk-ctl: Save/restore registers when RPM routines are called