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authorBoris BREZILLON <boris.brezillon@free-electrons.com>2014-06-07 01:36:11 +0400
committerLinus Torvalds <torvalds@linux-foundation.org>2014-06-07 03:08:08 +0400
commit9dcc87fec8947308e0111c65dcd881e6aa5b1673 (patch)
tree6bcbad03da392aea8b11dcf4c4947744e6138698 /arch/arm
parent2fe121e1f5aa3bf31b418a9790db6c400e922291 (diff)
downloadlinux-9dcc87fec8947308e0111c65dcd881e6aa5b1673.tar.xz
ARM: at91: fix at91_sysirq_mask_rtc for sam9x5 SoCs
sam9x5 SoCs have the following errata: "RTC: Interrupt Mask Register cannot be used Interrupt Mask Register read always returns 0." Hence we should not rely on what IMR claims about already masked IRQs and just disable all IRQs. Signed-off-by: Boris BREZILLON <boris.brezillon@free-electrons.com> Reported-by: Bryan Evenson <bevenson@melinkcorp.com> Reviewed-by: Johan Hovold <johan@hovold.com> Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com> Cc: Bryan Evenson <bevenson@melinkcorp.com> Cc: Andrew Victor <linux@maxim.org.za> Cc: Jean-Christophe Plagniol-Villard <plagnioj@jcrosoft.com> Cc: Alessandro Zummo <a.zummo@towertech.it> Cc: Mark Roszko <mark.roszko@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch/arm')
-rw-r--r--arch/arm/mach-at91/sysirq_mask.c22
1 files changed, 13 insertions, 9 deletions
diff --git a/arch/arm/mach-at91/sysirq_mask.c b/arch/arm/mach-at91/sysirq_mask.c
index 2ba694f9626b..f8bc3511a8c8 100644
--- a/arch/arm/mach-at91/sysirq_mask.c
+++ b/arch/arm/mach-at91/sysirq_mask.c
@@ -25,24 +25,28 @@
#include "generic.h"
-#define AT91_RTC_IDR 0x24 /* Interrupt Disable Register */
-#define AT91_RTC_IMR 0x28 /* Interrupt Mask Register */
+#define AT91_RTC_IDR 0x24 /* Interrupt Disable Register */
+#define AT91_RTC_IMR 0x28 /* Interrupt Mask Register */
+#define AT91_RTC_IRQ_MASK 0x1f /* Available IRQs mask */
void __init at91_sysirq_mask_rtc(u32 rtc_base)
{
void __iomem *base;
- u32 mask;
base = ioremap(rtc_base, 64);
if (!base)
return;
- mask = readl_relaxed(base + AT91_RTC_IMR);
- if (mask) {
- pr_info("AT91: Disabling rtc irq\n");
- writel_relaxed(mask, base + AT91_RTC_IDR);
- (void)readl_relaxed(base + AT91_RTC_IMR); /* flush */
- }
+ /*
+ * sam9x5 SoCs have the following errata:
+ * "RTC: Interrupt Mask Register cannot be used
+ * Interrupt Mask Register read always returns 0."
+ *
+ * Hence we're not relying on IMR values to disable
+ * interrupts.
+ */
+ writel_relaxed(AT91_RTC_IRQ_MASK, base + AT91_RTC_IDR);
+ (void)readl_relaxed(base + AT91_RTC_IMR); /* flush */
iounmap(base);
}