diff mbox series

[v3] thermal: rcar_thermal: Use platform_get_irq_optional() to get the interrupt

Message ID 20220104145212.4608-1-prabhakar.mahadev-lad.rj@bp.renesas.com
State Accepted
Commit 3277e022a1c31f5041753942b3d9006174ca7aa2
Headers show
Series [v3] thermal: rcar_thermal: Use platform_get_irq_optional() to get the interrupt | expand

Commit Message

Prabhakar Mahadev Lad Jan. 4, 2022, 2:52 p.m. UTC
platform_get_resource(pdev, IORESOURCE_IRQ, ..) relies on static
allocation of IRQ resources in DT core code, this causes an issue
when using hierarchical interrupt domains using "interrupts" property
in the node as this bypasses the hierarchical setup and messes up the
irq chaining.

In preparation for removal of static setup of IRQ resource from DT core
code use platform_get_irq_optional().

Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
---
v2-v3:
* Fixed review comment pointed by Andy

v1->v2
* Simplified checking error code
* Break loop earlier if no interrupts are seen

v1: https://lkml.org/lkml/2021/12/18/163
---
 drivers/thermal/rcar_thermal.c | 17 ++++++++++++-----
 1 file changed, 12 insertions(+), 5 deletions(-)

Comments

Lad, Prabhakar Jan. 5, 2022, 7:25 p.m. UTC | #1
Hi Niklas,

Thank you for the review.

On Wed, Jan 5, 2022 at 7:13 PM Niklas Söderlund
<niklas.soderlund@ragnatech.se> wrote:
>
> Hi Lad,
>
> Thanks for your work.
>
> On 2022-01-04 14:52:11 +0000, Lad Prabhakar wrote:
> > platform_get_resource(pdev, IORESOURCE_IRQ, ..) relies on static
> > allocation of IRQ resources in DT core code, this causes an issue
> > when using hierarchical interrupt domains using "interrupts" property
> > in the node as this bypasses the hierarchical setup and messes up the
> > irq chaining.
> >
> > In preparation for removal of static setup of IRQ resource from DT core
> > code use platform_get_irq_optional().
> >
> > Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
> > ---
> > v2-v3:
> > * Fixed review comment pointed by Andy
> >
> > v1->v2
> > * Simplified checking error code
> > * Break loop earlier if no interrupts are seen
> >
> > v1: https://lkml.org/lkml/2021/12/18/163
> > ---
> >  drivers/thermal/rcar_thermal.c | 17 ++++++++++++-----
> >  1 file changed, 12 insertions(+), 5 deletions(-)
> >
> > diff --git a/drivers/thermal/rcar_thermal.c b/drivers/thermal/rcar_thermal.c
> > index b49f04daaf47..e480f7290ccf 100644
> > --- a/drivers/thermal/rcar_thermal.c
> > +++ b/drivers/thermal/rcar_thermal.c
> > @@ -445,7 +445,7 @@ static int rcar_thermal_probe(struct platform_device *pdev)
> >       struct rcar_thermal_common *common;
> >       struct rcar_thermal_priv *priv;
> >       struct device *dev = &pdev->dev;
> > -     struct resource *res, *irq;
> > +     struct resource *res;
> >       const struct rcar_thermal_chip *chip = of_device_get_match_data(dev);
> >       int mres = 0;
> >       int i;
> > @@ -467,9 +467,16 @@ static int rcar_thermal_probe(struct platform_device *pdev)
> >       pm_runtime_get_sync(dev);
> >
> >       for (i = 0; i < chip->nirqs; i++) {
> > -             irq = platform_get_resource(pdev, IORESOURCE_IRQ, i);
> > -             if (!irq)
> > -                     continue;
> > +             int irq;
> > +
> > +             irq = platform_get_irq_optional(pdev, i);
> > +             if (irq < 0 && irq != -ENXIO) {
> > +                     ret = irq;
> > +                     goto error_unregister;
> > +             }
> > +             if (!irq || irq == -ENXIO)
> > +                     break;
>
> This do not look correct and differs form v1.
>
> In the old code if we can't get an IRQ the loop is continued. This is
> used to detect if interrupts are supported or not on the platform.  This
> change will fail on all systems that don't describes interrupts in DT
> while the driver can function without interrupts.
>
There are no non-DT users for this driver. Do you see this driver
being used in a non-DT environment in near future?

> Is there a reason you wish to do this change in addition to the switch
> to platform_get_irq_optional()? If so I think that should be done in a
> separate patch.
>
No other reason, It was suggested by Gerrt too to use a break instead
of continue in v1.

Cheers,
Prabhakar
Andy Shevchenko Jan. 6, 2022, 2:28 p.m. UTC | #2
On Tue, Jan 4, 2022 at 4:52 PM Lad Prabhakar
<prabhakar.mahadev-lad.rj@bp.renesas.com> wrote:
>
> platform_get_resource(pdev, IORESOURCE_IRQ, ..) relies on static
> allocation of IRQ resources in DT core code, this causes an issue
> when using hierarchical interrupt domains using "interrupts" property
> in the node as this bypasses the hierarchical setup and messes up the
> irq chaining.
>
> In preparation for removal of static setup of IRQ resource from DT core
> code use platform_get_irq_optional().

...

>         for (i = 0; i < chip->nirqs; i++) {
> -               irq = platform_get_resource(pdev, IORESOURCE_IRQ, i);
> -               if (!irq)
> -                       continue;
> +               int irq;

> +               irq = platform_get_irq_optional(pdev, i);
> +               if (irq < 0 && irq != -ENXIO) {
> +                       ret = irq;
> +                       goto error_unregister;
> +               }
> +               if (!irq || irq == -ENXIO)
> +                       break;

Wouldn't be better to assign to ret

               ret = platform_get_irq_optional(pdev, i);
               if (ret < 0 && ret != -ENXIO)
                       goto error_unregister;
               if (ret > 0)
                       irq = ret;
               else
                       break;

?
Lad, Prabhakar Jan. 6, 2022, 3:39 p.m. UTC | #3
Hi Niklas,

On Thu, Jan 6, 2022 at 3:29 PM Niklas Söderlund
<niklas.soderlund@ragnatech.se> wrote:
>
> Hi Lad,
>
> On 2022-01-05 19:25:25 +0000, Lad, Prabhakar wrote:
> > Hi Niklas,
> >
> > Thank you for the review.
> >
> > On Wed, Jan 5, 2022 at 7:13 PM Niklas Söderlund
> > <niklas.soderlund@ragnatech.se> wrote:
> > >
> > > Hi Lad,
> > >
> > > Thanks for your work.
> > >
> > > On 2022-01-04 14:52:11 +0000, Lad Prabhakar wrote:
> > > > platform_get_resource(pdev, IORESOURCE_IRQ, ..) relies on static
> > > > allocation of IRQ resources in DT core code, this causes an issue
> > > > when using hierarchical interrupt domains using "interrupts" property
> > > > in the node as this bypasses the hierarchical setup and messes up the
> > > > irq chaining.
> > > >
> > > > In preparation for removal of static setup of IRQ resource from DT core
> > > > code use platform_get_irq_optional().
> > > >
> > > > Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
> > > > ---
> > > > v2-v3:
> > > > * Fixed review comment pointed by Andy
> > > >
> > > > v1->v2
> > > > * Simplified checking error code
> > > > * Break loop earlier if no interrupts are seen
> > > >
> > > > v1: https://lkml.org/lkml/2021/12/18/163
> > > > ---
> > > >  drivers/thermal/rcar_thermal.c | 17 ++++++++++++-----
> > > >  1 file changed, 12 insertions(+), 5 deletions(-)
> > > >
> > > > diff --git a/drivers/thermal/rcar_thermal.c b/drivers/thermal/rcar_thermal.c
> > > > index b49f04daaf47..e480f7290ccf 100644
> > > > --- a/drivers/thermal/rcar_thermal.c
> > > > +++ b/drivers/thermal/rcar_thermal.c
> > > > @@ -445,7 +445,7 @@ static int rcar_thermal_probe(struct platform_device *pdev)
> > > >       struct rcar_thermal_common *common;
> > > >       struct rcar_thermal_priv *priv;
> > > >       struct device *dev = &pdev->dev;
> > > > -     struct resource *res, *irq;
> > > > +     struct resource *res;
> > > >       const struct rcar_thermal_chip *chip = of_device_get_match_data(dev);
> > > >       int mres = 0;
> > > >       int i;
> > > > @@ -467,9 +467,16 @@ static int rcar_thermal_probe(struct platform_device *pdev)
> > > >       pm_runtime_get_sync(dev);
> > > >
> > > >       for (i = 0; i < chip->nirqs; i++) {
> > > > -             irq = platform_get_resource(pdev, IORESOURCE_IRQ, i);
> > > > -             if (!irq)
> > > > -                     continue;
> > > > +             int irq;
> > > > +
> > > > +             irq = platform_get_irq_optional(pdev, i);
> > > > +             if (irq < 0 && irq != -ENXIO) {
> > > > +                     ret = irq;
> > > > +                     goto error_unregister;
> > > > +             }
> > > > +             if (!irq || irq == -ENXIO)
> > > > +                     break;
> > >
> > > This do not look correct and differs form v1.
> > >
> > > In the old code if we can't get an IRQ the loop is continued. This is
> > > used to detect if interrupts are supported or not on the platform.  This
> > > change will fail on all systems that don't describes interrupts in DT
> > > while the driver can function without interrupts.
> > >
> > There are no non-DT users for this driver. Do you see this driver
> > being used in a non-DT environment in near future?
>
> No, maybe I was unclear sorry about that. What I intended to say was
> that this change will break platforms that that make use of this driver
> but do not describe interrupts in its DT description. As with this
> change not describing interrupts is consider an error.
>
> For example checkout thermal@ffc48000 in arch/arm/boot/dts/r8a7779.dtsi.
>
If the interrupts are missing in DT (for example in [1])
platform_get_irq_optional() will return -ENXIO with this patch this
error code is handled gracefully i.e. it doesn't return error and
breaks instead keeping the orignal behavior of the driver.

[1] arch/arm/boot/dts/r8a7779.dtsi

Cheers,
Prabhakar
Andy Shevchenko Jan. 6, 2022, 4:04 p.m. UTC | #4
On Thu, Jan 6, 2022 at 5:29 PM Niklas Söderlund
<niklas.soderlund@ragnatech.se> wrote:
> On 2022-01-05 19:25:25 +0000, Lad, Prabhakar wrote:
> > On Wed, Jan 5, 2022 at 7:13 PM Niklas Söderlund
> > <niklas.soderlund@ragnatech.se> wrote:
> > > On 2022-01-04 14:52:11 +0000, Lad Prabhakar wrote:

...

> > > > +             if (!irq || irq == -ENXIO)
> > > > +                     break;
> > >
> > > This do not look correct and differs form v1.
> > >
> > > In the old code if we can't get an IRQ the loop is continued. This is
> > > used to detect if interrupts are supported or not on the platform.  This
> > > change will fail on all systems that don't describes interrupts in DT
> > > while the driver can function without interrupts.
> > >
> > There are no non-DT users for this driver. Do you see this driver
> > being used in a non-DT environment in near future?
>
> No, maybe I was unclear sorry about that. What I intended to say was
> that this change will break platforms that that make use of this driver
> but do not describe interrupts in its DT description. As with this
> change not describing interrupts is consider an error.
>
> For example checkout thermal@ffc48000 in arch/arm/boot/dts/r8a7779.dtsi.

> > > Is there a reason you wish to do this change in addition to the switch
> > > to platform_get_irq_optional()? If so I think that should be done in a
> > > separate patch.
> > >
> > No other reason, It was suggested by Gerrt too to use a break instead
> > of continue in v1.
>
> I think we need to keep the original behavior.

I don't see how this can break those. Or are you stating that some of
them are using board files with 0 as a valid (v)IRQ?
diff mbox series

Patch

diff --git a/drivers/thermal/rcar_thermal.c b/drivers/thermal/rcar_thermal.c
index b49f04daaf47..e480f7290ccf 100644
--- a/drivers/thermal/rcar_thermal.c
+++ b/drivers/thermal/rcar_thermal.c
@@ -445,7 +445,7 @@  static int rcar_thermal_probe(struct platform_device *pdev)
 	struct rcar_thermal_common *common;
 	struct rcar_thermal_priv *priv;
 	struct device *dev = &pdev->dev;
-	struct resource *res, *irq;
+	struct resource *res;
 	const struct rcar_thermal_chip *chip = of_device_get_match_data(dev);
 	int mres = 0;
 	int i;
@@ -467,9 +467,16 @@  static int rcar_thermal_probe(struct platform_device *pdev)
 	pm_runtime_get_sync(dev);
 
 	for (i = 0; i < chip->nirqs; i++) {
-		irq = platform_get_resource(pdev, IORESOURCE_IRQ, i);
-		if (!irq)
-			continue;
+		int irq;
+
+		irq = platform_get_irq_optional(pdev, i);
+		if (irq < 0 && irq != -ENXIO) {
+			ret = irq;
+			goto error_unregister;
+		}
+		if (!irq || irq == -ENXIO)
+			break;
+
 		if (!common->base) {
 			/*
 			 * platform has IRQ support.
@@ -487,7 +494,7 @@  static int rcar_thermal_probe(struct platform_device *pdev)
 			idle = 0; /* polling delay is not needed */
 		}
 
-		ret = devm_request_irq(dev, irq->start, rcar_thermal_irq,
+		ret = devm_request_irq(dev, irq, rcar_thermal_irq,
 				       IRQF_SHARED, dev_name(dev), common);
 		if (ret) {
 			dev_err(dev, "irq request failed\n ");