Patchwork ARM: mxs: icoll: Fix interrupts gpio bank 0

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Submitter Markus Pargmann
Date May 28, 2013, 3 p.m.
Message ID <1369753257-11091-1-git-send-email-mpa@pengutronix.de>
Download mbox | patch
Permalink /patch/246878/
State New
Headers show

Comments

Markus Pargmann - May 28, 2013, 3 p.m.
The mxs interrupt controller does not support polling for interrupts,
but the driver still does it, which is a relict from
pre-MULTI_IRQ_HANDLER times.

The existing code assumes that 0x7f means no interrupt, but this value
is an actually valid irq number, namely gpio bank 0's irq. This results
in the driver not detecting when irq 0x7f is active which makes the
machine effectively dead lock.

This patch removes the interrupt poll loop and allows usage of gpio0
interrupt without an infinite loop.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
Cc: stable@vger.kernel.org
---
 drivers/irqchip/irq-mxs.c | 14 ++++----------
 1 file changed, 4 insertions(+), 10 deletions(-)
Shawn Guo - May 29, 2013, 2:42 p.m.
On Tue, May 28, 2013 at 05:00:57PM +0200, Markus Pargmann wrote:
> The mxs interrupt controller does not support polling for interrupts,
> but the driver still does it, which is a relict from
> pre-MULTI_IRQ_HANDLER times.
> 
> The existing code assumes that 0x7f means no interrupt, but this value
> is an actually valid irq number, namely gpio bank 0's irq. This results
> in the driver not detecting when irq 0x7f is active which makes the
> machine effectively dead lock.
> 
> This patch removes the interrupt poll loop and allows usage of gpio0
> interrupt without an infinite loop.
> 
> Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
> Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
> Cc: stable@vger.kernel.org

Thomas, can you please help handle the fix?  If yes, here is my ack.

Acked-by: Shawn Guo <shawn.guo@linaro.org>

Otherwise, I can send it through arm-soc tree if you're fine with it.

Shawn

> ---
>  drivers/irqchip/irq-mxs.c | 14 ++++----------
>  1 file changed, 4 insertions(+), 10 deletions(-)
> 
> diff --git a/drivers/irqchip/irq-mxs.c b/drivers/irqchip/irq-mxs.c
> index 29889bb..63b3d4e 100644
> --- a/drivers/irqchip/irq-mxs.c
> +++ b/drivers/irqchip/irq-mxs.c
> @@ -76,16 +76,10 @@ asmlinkage void __exception_irq_entry icoll_handle_irq(struct pt_regs *regs)
>  {
>  	u32 irqnr;
>  
> -	do {
> -		irqnr = __raw_readl(icoll_base + HW_ICOLL_STAT_OFFSET);
> -		if (irqnr != 0x7f) {
> -			__raw_writel(irqnr, icoll_base + HW_ICOLL_VECTOR);
> -			irqnr = irq_find_mapping(icoll_domain, irqnr);
> -			handle_IRQ(irqnr, regs);
> -			continue;
> -		}
> -		break;
> -	} while (1);
> +	irqnr = __raw_readl(icoll_base + HW_ICOLL_STAT_OFFSET);
> +	__raw_writel(irqnr, icoll_base + HW_ICOLL_VECTOR);
> +	irqnr = irq_find_mapping(icoll_domain, irqnr);
> +	handle_IRQ(irqnr, regs);
>  }
>  
>  static int icoll_irq_domain_map(struct irq_domain *d, unsigned int virq,
> -- 
> 1.8.2.rc2
>
Shawn Guo - June 3, 2013, 3:15 p.m.
On Wed, May 29, 2013 at 10:42:58PM +0800, Shawn Guo wrote:
> On Tue, May 28, 2013 at 05:00:57PM +0200, Markus Pargmann wrote:
> > The mxs interrupt controller does not support polling for interrupts,
> > but the driver still does it, which is a relict from
> > pre-MULTI_IRQ_HANDLER times.
> > 
> > The existing code assumes that 0x7f means no interrupt, but this value
> > is an actually valid irq number, namely gpio bank 0's irq. This results
> > in the driver not detecting when irq 0x7f is active which makes the
> > machine effectively dead lock.
> > 
> > This patch removes the interrupt poll loop and allows usage of gpio0
> > interrupt without an infinite loop.
> > 
> > Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
> > Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
> > Cc: stable@vger.kernel.org
> 
> Thomas, can you please help handle the fix?  If yes, here is my ack.
> 
> Acked-by: Shawn Guo <shawn.guo@linaro.org>
> 
> Otherwise, I can send it through arm-soc tree if you're fine with it.

Thomas,

I'm sending the fix through arm-soc, and let me know if you have problem
with that.

Shawn

Patch

diff --git a/drivers/irqchip/irq-mxs.c b/drivers/irqchip/irq-mxs.c
index 29889bb..63b3d4e 100644
--- a/drivers/irqchip/irq-mxs.c
+++ b/drivers/irqchip/irq-mxs.c
@@ -76,16 +76,10 @@  asmlinkage void __exception_irq_entry icoll_handle_irq(struct pt_regs *regs)
 {
 	u32 irqnr;
 
-	do {
-		irqnr = __raw_readl(icoll_base + HW_ICOLL_STAT_OFFSET);
-		if (irqnr != 0x7f) {
-			__raw_writel(irqnr, icoll_base + HW_ICOLL_VECTOR);
-			irqnr = irq_find_mapping(icoll_domain, irqnr);
-			handle_IRQ(irqnr, regs);
-			continue;
-		}
-		break;
-	} while (1);
+	irqnr = __raw_readl(icoll_base + HW_ICOLL_STAT_OFFSET);
+	__raw_writel(irqnr, icoll_base + HW_ICOLL_VECTOR);
+	irqnr = irq_find_mapping(icoll_domain, irqnr);
+	handle_IRQ(irqnr, regs);
 }
 
 static int icoll_irq_domain_map(struct irq_domain *d, unsigned int virq,