Patchwork ARM: imx: drop support for irq priorisation

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Submitter Uwe Kleine-König
Date Nov. 4, 2013, 8:17 a.m.
Message ID <1383553022-6983-1-git-send-email-u.kleine-koenig@pengutronix.de>
Download mbox | patch
Permalink /patch/288126/
State New
Headers show

Comments

Uwe Kleine-König - Nov. 4, 2013, 8:17 a.m.
The code for irq priorisation support doesn't have any in-tree users and
the Kconfig description does wrong promises because nowadays irq
handlers are called with irqs disabled, so no high prioritized irq can
interrupt a lower prioritized handler.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
---
 arch/arm/mach-imx/Kconfig      | 10 ----------
 arch/arm/mach-imx/avic.c       | 25 -------------------------
 arch/arm/mach-imx/irq-common.h |  1 -
 3 files changed, 36 deletions(-)
Sascha Hauer - Nov. 4, 2013, 8:41 a.m.
On Mon, Nov 04, 2013 at 09:17:02AM +0100, Uwe Kleine-König wrote:
> The code for irq priorisation support doesn't have any in-tree users and
> the Kconfig description does wrong promises because nowadays irq
> handlers are called with irqs disabled, so no high prioritized irq can
> interrupt a lower prioritized handler.
> 
> Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>

Acked-by: Sascha Hauer <s.hauer@pengutronix.de>

Sascha

> ---
>  arch/arm/mach-imx/Kconfig      | 10 ----------
>  arch/arm/mach-imx/avic.c       | 25 -------------------------
>  arch/arm/mach-imx/irq-common.h |  1 -
>  3 files changed, 36 deletions(-)
> 
> diff --git a/arch/arm/mach-imx/Kconfig b/arch/arm/mach-imx/Kconfig
> index 15c9ae3..9431729 100644
> --- a/arch/arm/mach-imx/Kconfig
> +++ b/arch/arm/mach-imx/Kconfig
> @@ -20,16 +20,6 @@ config ARCH_MXC
>  menu "Freescale i.MX support"
>  	depends on ARCH_MXC
>  
> -config MXC_IRQ_PRIOR
> -	bool "Use IRQ priority"
> -	help
> -	  Select this if you want to use prioritized IRQ handling.
> -	  This feature prevents higher priority ISR to be interrupted
> -	  by lower priority IRQ.
> -	  This may be useful in embedded applications, where are strong
> -	  requirements for timing.
> -	  Say N here, unless you have a specialized requirement.
> -
>  config MXC_TZIC
>  	bool
>  
> diff --git a/arch/arm/mach-imx/avic.c b/arch/arm/mach-imx/avic.c
> index e163ec7..8d1df2e 100644
> --- a/arch/arm/mach-imx/avic.c
> +++ b/arch/arm/mach-imx/avic.c
> @@ -54,28 +54,6 @@
>  static void __iomem *avic_base;
>  static struct irq_domain *domain;
>  
> -#ifdef CONFIG_MXC_IRQ_PRIOR
> -static int avic_irq_set_priority(unsigned char irq, unsigned char prio)
> -{
> -	struct irq_data *d = irq_get_irq_data(irq);
> -	unsigned int temp;
> -	unsigned int mask = 0x0F << irq % 8 * 4;
> -
> -	irq = d->hwirq;
> -
> -	if (irq >= AVIC_NUM_IRQS)
> -		return -EINVAL;
> -
> -	temp = __raw_readl(avic_base + AVIC_NIPRIORITY(irq / 8));
> -	temp &= ~mask;
> -	temp |= prio & mask;
> -
> -	__raw_writel(temp, avic_base + AVIC_NIPRIORITY(irq / 8));
> -
> -	return 0;
> -}
> -#endif
> -
>  #ifdef CONFIG_FIQ
>  static int avic_set_irq_fiq(unsigned int irq, unsigned int type)
>  {
> @@ -102,9 +80,6 @@ static int avic_set_irq_fiq(unsigned int irq, unsigned int type)
>  
>  
>  static struct mxc_extra_irq avic_extra_irq = {
> -#ifdef CONFIG_MXC_IRQ_PRIOR
> -	.set_priority = avic_irq_set_priority,
> -#endif
>  #ifdef CONFIG_FIQ
>  	.set_irq_fiq = avic_set_irq_fiq,
>  #endif
> diff --git a/arch/arm/mach-imx/irq-common.h b/arch/arm/mach-imx/irq-common.h
> index 5b2dabb..6e3175d 100644
> --- a/arch/arm/mach-imx/irq-common.h
> +++ b/arch/arm/mach-imx/irq-common.h
> @@ -24,7 +24,6 @@
>  
>  struct mxc_extra_irq
>  {
> -	int (*set_priority)(unsigned char irq, unsigned char prio);
>  	int (*set_irq_fiq)(unsigned int irq, unsigned int type);
>  };
>  
> -- 
> 1.8.4.rc3
> 
>
Uwe Kleine-König - Nov. 4, 2013, 9:48 a.m.
Hello Shawn,

I didn't add you to the list of recipents for this patch after
consulting the MAINTAINERS file. Sascha now told me that it's probably
you who takes this patch?! I suggest to fix MAINTAINERS accordingly.
Maybe just merge the entries "ARM/FREESCALE IMX / MXC ARM ARCHITECTURE"
and "ARM/FREESCALE IMX6"?

Best regards
Uwe

On Mon, Nov 04, 2013 at 09:41:29AM +0100, Sascha Hauer wrote:
> On Mon, Nov 04, 2013 at 09:17:02AM +0100, Uwe Kleine-König wrote:
> > The code for irq priorisation support doesn't have any in-tree users and
> > the Kconfig description does wrong promises because nowadays irq
> > handlers are called with irqs disabled, so no high prioritized irq can
> > interrupt a lower prioritized handler.
> > 
> > Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
> 
> Acked-by: Sascha Hauer <s.hauer@pengutronix.de>
> 
> Sascha
> 
> > ---
> >  arch/arm/mach-imx/Kconfig      | 10 ----------
> >  arch/arm/mach-imx/avic.c       | 25 -------------------------
> >  arch/arm/mach-imx/irq-common.h |  1 -
> >  3 files changed, 36 deletions(-)
> > 
> > diff --git a/arch/arm/mach-imx/Kconfig b/arch/arm/mach-imx/Kconfig
> > index 15c9ae3..9431729 100644
> > --- a/arch/arm/mach-imx/Kconfig
> > +++ b/arch/arm/mach-imx/Kconfig
> > @@ -20,16 +20,6 @@ config ARCH_MXC
> >  menu "Freescale i.MX support"
> >  	depends on ARCH_MXC
> >  
> > -config MXC_IRQ_PRIOR
> > -	bool "Use IRQ priority"
> > -	help
> > -	  Select this if you want to use prioritized IRQ handling.
> > -	  This feature prevents higher priority ISR to be interrupted
> > -	  by lower priority IRQ.
> > -	  This may be useful in embedded applications, where are strong
> > -	  requirements for timing.
> > -	  Say N here, unless you have a specialized requirement.
> > -
> >  config MXC_TZIC
> >  	bool
> >  
> > diff --git a/arch/arm/mach-imx/avic.c b/arch/arm/mach-imx/avic.c
> > index e163ec7..8d1df2e 100644
> > --- a/arch/arm/mach-imx/avic.c
> > +++ b/arch/arm/mach-imx/avic.c
> > @@ -54,28 +54,6 @@
> >  static void __iomem *avic_base;
> >  static struct irq_domain *domain;
> >  
> > -#ifdef CONFIG_MXC_IRQ_PRIOR
> > -static int avic_irq_set_priority(unsigned char irq, unsigned char prio)
> > -{
> > -	struct irq_data *d = irq_get_irq_data(irq);
> > -	unsigned int temp;
> > -	unsigned int mask = 0x0F << irq % 8 * 4;
> > -
> > -	irq = d->hwirq;
> > -
> > -	if (irq >= AVIC_NUM_IRQS)
> > -		return -EINVAL;
> > -
> > -	temp = __raw_readl(avic_base + AVIC_NIPRIORITY(irq / 8));
> > -	temp &= ~mask;
> > -	temp |= prio & mask;
> > -
> > -	__raw_writel(temp, avic_base + AVIC_NIPRIORITY(irq / 8));
> > -
> > -	return 0;
> > -}
> > -#endif
> > -
> >  #ifdef CONFIG_FIQ
> >  static int avic_set_irq_fiq(unsigned int irq, unsigned int type)
> >  {
> > @@ -102,9 +80,6 @@ static int avic_set_irq_fiq(unsigned int irq, unsigned int type)
> >  
> >  
> >  static struct mxc_extra_irq avic_extra_irq = {
> > -#ifdef CONFIG_MXC_IRQ_PRIOR
> > -	.set_priority = avic_irq_set_priority,
> > -#endif
> >  #ifdef CONFIG_FIQ
> >  	.set_irq_fiq = avic_set_irq_fiq,
> >  #endif
> > diff --git a/arch/arm/mach-imx/irq-common.h b/arch/arm/mach-imx/irq-common.h
> > index 5b2dabb..6e3175d 100644
> > --- a/arch/arm/mach-imx/irq-common.h
> > +++ b/arch/arm/mach-imx/irq-common.h
> > @@ -24,7 +24,6 @@
> >  
> >  struct mxc_extra_irq
> >  {
> > -	int (*set_priority)(unsigned char irq, unsigned char prio);
> >  	int (*set_irq_fiq)(unsigned int irq, unsigned int type);
> >  };
> >  
> > -- 
> > 1.8.4.rc3
> > 
> > 
> 
> -- 
> Pengutronix e.K.                           |                             |
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>
Shawn Guo - Nov. 4, 2013, 1:44 p.m.
On Mon, Nov 04, 2013 at 09:17:02AM +0100, Uwe Kleine-König wrote:
> The code for irq priorisation support doesn't have any in-tree users and
> the Kconfig description does wrong promises because nowadays irq
> handlers are called with irqs disabled, so no high prioritized irq can
> interrupt a lower prioritized handler.
> 
> Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>

Applied, thanks.
Shawn Guo - Nov. 4, 2013, 1:53 p.m.
Hi Uwe,

On Mon, Nov 04, 2013 at 10:48:10AM +0100, Uwe Kleine-König wrote:
> Hello Shawn,
> 
> I didn't add you to the list of recipents for this patch after
> consulting the MAINTAINERS file. Sascha now told me that it's probably
> you who takes this patch?!

Ah, yes.  I've been helping collect i.MX patches for a couple of cycles
with Sascha's nod.

> I suggest to fix MAINTAINERS accordingly.
> Maybe just merge the entries "ARM/FREESCALE IMX / MXC ARM ARCHITECTURE"
> and "ARM/FREESCALE IMX6"?

Yea, that should help me handle i.MX patches more quickly.  If you send
a patch for it, I would suggest merge MXS entry into IMX one as well,
and add "F: arch/arm/boot/dts/imx*" line.

Shawn

Patch

diff --git a/arch/arm/mach-imx/Kconfig b/arch/arm/mach-imx/Kconfig
index 15c9ae3..9431729 100644
--- a/arch/arm/mach-imx/Kconfig
+++ b/arch/arm/mach-imx/Kconfig
@@ -20,16 +20,6 @@  config ARCH_MXC
 menu "Freescale i.MX support"
 	depends on ARCH_MXC
 
-config MXC_IRQ_PRIOR
-	bool "Use IRQ priority"
-	help
-	  Select this if you want to use prioritized IRQ handling.
-	  This feature prevents higher priority ISR to be interrupted
-	  by lower priority IRQ.
-	  This may be useful in embedded applications, where are strong
-	  requirements for timing.
-	  Say N here, unless you have a specialized requirement.
-
 config MXC_TZIC
 	bool
 
diff --git a/arch/arm/mach-imx/avic.c b/arch/arm/mach-imx/avic.c
index e163ec7..8d1df2e 100644
--- a/arch/arm/mach-imx/avic.c
+++ b/arch/arm/mach-imx/avic.c
@@ -54,28 +54,6 @@ 
 static void __iomem *avic_base;
 static struct irq_domain *domain;
 
-#ifdef CONFIG_MXC_IRQ_PRIOR
-static int avic_irq_set_priority(unsigned char irq, unsigned char prio)
-{
-	struct irq_data *d = irq_get_irq_data(irq);
-	unsigned int temp;
-	unsigned int mask = 0x0F << irq % 8 * 4;
-
-	irq = d->hwirq;
-
-	if (irq >= AVIC_NUM_IRQS)
-		return -EINVAL;
-
-	temp = __raw_readl(avic_base + AVIC_NIPRIORITY(irq / 8));
-	temp &= ~mask;
-	temp |= prio & mask;
-
-	__raw_writel(temp, avic_base + AVIC_NIPRIORITY(irq / 8));
-
-	return 0;
-}
-#endif
-
 #ifdef CONFIG_FIQ
 static int avic_set_irq_fiq(unsigned int irq, unsigned int type)
 {
@@ -102,9 +80,6 @@  static int avic_set_irq_fiq(unsigned int irq, unsigned int type)
 
 
 static struct mxc_extra_irq avic_extra_irq = {
-#ifdef CONFIG_MXC_IRQ_PRIOR
-	.set_priority = avic_irq_set_priority,
-#endif
 #ifdef CONFIG_FIQ
 	.set_irq_fiq = avic_set_irq_fiq,
 #endif
diff --git a/arch/arm/mach-imx/irq-common.h b/arch/arm/mach-imx/irq-common.h
index 5b2dabb..6e3175d 100644
--- a/arch/arm/mach-imx/irq-common.h
+++ b/arch/arm/mach-imx/irq-common.h
@@ -24,7 +24,6 @@ 
 
 struct mxc_extra_irq
 {
-	int (*set_priority)(unsigned char irq, unsigned char prio);
 	int (*set_irq_fiq)(unsigned int irq, unsigned int type);
 };