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From: Kevin Cernekee <cernekee@gmail.com>
To: tglx@linutronix.de, jason@lakedaemon.net, linux-sh@vger.kernel.org
Cc: arnd@arndb.de, f.fainelli@gmail.com, ralf@linux-mips.org,
	sergei.shtylyov@cogentembedded.com, linux-kernel@vger.kernel.org,
	devicetree@vger.kernel.org, mbizon@freebox.fr, jogo@openwrt.org,
	linux-mips@linux-mips.org
Subject: [PATCH V4 06/14] irqchip: bcm7120-l2: Eliminate bad IRQ check
Date: Thu,  6 Nov 2014 22:44:21 -0800	[thread overview]
Message-ID: <1415342669-30640-7-git-send-email-cernekee@gmail.com> (raw)
In-Reply-To: <1415342669-30640-1-git-send-email-cernekee@gmail.com>

This check may be prone to race conditions, e.g.

1) Some external event (e.g. GPIO level) causes an IRQ to become pending
2) Peripheral asserts the L2 IRQ
3) CPU takes an interrupt
4) The event from #1 goes away
5) bcm7120_l2_intc_irq_handle() reads back a 0 status

Unlike the hardware supported by brcmstb-l2, the bcm7120-l2 controller
does not latch the IRQ status.  Bits can change if the inputs to the
controller change.  Also, do_bad_IRQ() is an ARM-specific macro.

So let's just nuke it.

Signed-off-by: Kevin Cernekee <cernekee@gmail.com>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
---
 drivers/irqchip/irq-bcm7120-l2.c | 13 ++-----------
 1 file changed, 2 insertions(+), 11 deletions(-)

diff --git a/drivers/irqchip/irq-bcm7120-l2.c b/drivers/irqchip/irq-bcm7120-l2.c
index b9f4fb8..7086fe0 100644
--- a/drivers/irqchip/irq-bcm7120-l2.c
+++ b/drivers/irqchip/irq-bcm7120-l2.c
@@ -27,8 +27,6 @@
 
 #include "irqchip.h"
 
-#include <asm/mach/irq.h>
-
 /* Register offset in the L2 interrupt controller */
 #define IRQEN		0x00
 #define IRQSTAT		0x04
@@ -51,19 +49,12 @@ static void bcm7120_l2_intc_irq_handle(unsigned int irq, struct irq_desc *desc)
 	chained_irq_enter(chip, desc);
 
 	status = __raw_readl(b->base + IRQSTAT);
-
-	if (status == 0) {
-		do_bad_IRQ(irq, desc);
-		goto out;
-	}
-
-	do {
+	while (status) {
 		irq = ffs(status) - 1;
 		status &= ~(1 << irq);
 		generic_handle_irq(irq_find_mapping(b->domain, irq));
-	} while (status);
+	}
 
-out:
 	chained_irq_exit(chip, desc);
 }
 
-- 
2.1.1

  parent reply	other threads:[~2014-11-07  6:44 UTC|newest]

Thread overview: 32+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-11-07  6:44 [PATCH V4 00/14] genirq endian fixes; bcm7120/brcmstb IRQ updates Kevin Cernekee
2014-11-07  6:44 ` [PATCH V4 01/14] sh: Eliminate unused irq_reg_{readl,writel} accessors Kevin Cernekee
2014-11-10  8:13   ` Geert Uytterhoeven
2014-11-14 16:38     ` Ralf Baechle
2014-11-14 17:05       ` Jason Cooper
2014-11-16  9:34         ` Geert Uytterhoeven
2015-01-19 19:13           ` Geert Uytterhoeven
2015-01-24 17:51             ` Thomas Gleixner
2015-01-25 10:13               ` Geert Uytterhoeven
2014-11-07  6:44 ` [PATCH V4 02/14] genirq: Generic chip: Change irq_reg_{readl,writel} arguments Kevin Cernekee
2014-11-07  6:44 ` [PATCH V4 03/14] genirq: Generic chip: Allow irqchip drivers to override irq_reg_{readl,writel} Kevin Cernekee
2014-11-07  6:44 ` [PATCH V4 04/14] genirq: Generic chip: Add big endian I/O accessors Kevin Cernekee
2014-11-10 22:00   ` Kevin Hilman
2014-11-10 22:11     ` Kevin Cernekee
2014-11-10 23:03       ` Alexandre Belloni
2014-11-11 10:03         ` Boris Brezillon
2014-11-11 13:33         ` [PATCH] irqchip: atmel-aic: fix irqdomain initialization Boris Brezillon
2014-11-11 15:45           ` Kevin Hilman
2014-11-11 22:58           ` Jason Cooper
     [not found]             ` <20141111225800.GE3698-u4khhh1J0LxI1Ri9qeTfzeTW4wlIGRCZ@public.gmane.org>
2014-11-12  9:43               ` Boris Brezillon
2014-11-07  6:44 ` [PATCH V4 05/14] irqchip: brcmstb-l2: Eliminate dependency on ARM code Kevin Cernekee
2014-11-07  6:44 ` Kevin Cernekee [this message]
2014-11-07  6:44 ` [PATCH V4 07/14] irqchip: bcm7120-l2, brcmstb-l2: Remove ARM Kconfig dependency Kevin Cernekee
2014-11-07  6:44 ` [PATCH V4 08/14] irqchip: bcm7120-l2: Make sure all register accesses use base+offset Kevin Cernekee
2014-11-07  6:44 ` [PATCH V4 09/14] irqchip: bcm7120-l2: Fix missing nibble in gc->unused mask Kevin Cernekee
     [not found] ` <1415342669-30640-1-git-send-email-cernekee-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
2014-11-07  6:44   ` [PATCH V4 10/14] irqchip: bcm7120-l2: Use gc->mask_cache to simplify suspend/resume functions Kevin Cernekee
2014-11-07  6:44   ` [PATCH V4 14/14] irqchip: brcmstb-l2: Convert driver to use irq_reg_{readl,writel} Kevin Cernekee
2014-11-07  6:44 ` [PATCH V4 11/14] irqchip: bcm7120-l2: Extend driver to support 64+ bit controllers Kevin Cernekee
2014-11-07  6:44 ` [PATCH V4 12/14] irqchip: bcm7120-l2: Decouple driver from brcmstb-l2 Kevin Cernekee
2014-11-07  6:44 ` [PATCH V4 13/14] irqchip: bcm7120-l2: Convert driver to use irq_reg_{readl,writel} Kevin Cernekee
2014-11-07 12:27 ` [PATCH V4 00/14] genirq endian fixes; bcm7120/brcmstb IRQ updates Jason Cooper
     [not found]   ` <20141107122745.GJ3698-u4khhh1J0LxI1Ri9qeTfzeTW4wlIGRCZ@public.gmane.org>
2014-11-09  4:30     ` Jason Cooper

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