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authorJohan Hovold <jhovold@gmail.com>2013-10-16 11:56:15 +0200
committerNicolas Ferre <nicolas.ferre@atmel.com>2013-11-15 12:13:33 +0100
commit94c4c79f2f1acca6e69a50bff5a7d9027509c16b (patch)
tree85b5fdb02f99edb8b8f4368ea932c4d149fc9e1f /arch/arm
parent6de714c21a8ea315fffba6a93bbe537f4c1bf4f0 (diff)
downloadlinux-linaro-stable-94c4c79f2f1acca6e69a50bff5a7d9027509c16b.tar.gz
ARM: at91: fix hanged boot due to early rtt-interrupt
Make sure the RTT-interrupts are masked at boot by adding a new helper function to be used at SOC-init. This fixes hanged boot on all AT91 SOCs with an RTT, for example, if an RTT-alarm goes off after a non-clean shutdown (e.g. when using RTC wakeup). The RTC and RTT-peripherals are powered by backup power (VDDBU) (on all AT91 SOCs but RM9200) and are not reset on wake-up, user, watchdog or software reset. This means that their interrupts may be enabled during early boot if, for example, they where not disabled during a previous shutdown (e.g. due to a buggy driver or a non-clean shutdown such as a user reset). Furthermore, an RTC or RTT-alarm may also be active. The RTC and RTT-interrupts use the shared system-interrupt line, which is also used by the PIT, and if an interrupt occurs before a handler (e.g. RTC-driver) has been installed this leads to the system interrupt being disabled and prevents the system from booting. Note that when boot hangs due to an early RTC or RTT-interrupt, the only way to get the system to start again is to remove the backup power (e.g. battery) or to disable the interrupt manually from the bootloader. In particular, a user reset is not sufficient. Signed-off-by: Johan Hovold <jhovold@gmail.com> Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com> Cc: stable@vger.kernel.org # 3.11.x
Diffstat (limited to 'arch/arm')
-rw-r--r--arch/arm/mach-at91/at91sam9260.c2
-rw-r--r--arch/arm/mach-at91/at91sam9261.c2
-rw-r--r--arch/arm/mach-at91/at91sam9263.c3
-rw-r--r--arch/arm/mach-at91/at91sam9g45.c1
-rw-r--r--arch/arm/mach-at91/at91sam9rl.c1
-rw-r--r--arch/arm/mach-at91/generic.h1
-rw-r--r--arch/arm/mach-at91/sysirq_mask.c24
7 files changed, 34 insertions, 0 deletions
diff --git a/arch/arm/mach-at91/at91sam9260.c b/arch/arm/mach-at91/at91sam9260.c
index 5de6074b4f4f..ae10d14de700 100644
--- a/arch/arm/mach-at91/at91sam9260.c
+++ b/arch/arm/mach-at91/at91sam9260.c
@@ -349,6 +349,8 @@ static void __init at91sam9260_initialize(void)
arm_pm_idle = at91sam9_idle;
arm_pm_restart = at91sam9_alt_restart;
+ at91_sysirq_mask_rtt(AT91SAM9260_BASE_RTT);
+
/* Register GPIO subsystem */
at91_gpio_init(at91sam9260_gpio, 3);
}
diff --git a/arch/arm/mach-at91/at91sam9261.c b/arch/arm/mach-at91/at91sam9261.c
index 0e0793241ab7..e761e74ac64b 100644
--- a/arch/arm/mach-at91/at91sam9261.c
+++ b/arch/arm/mach-at91/at91sam9261.c
@@ -291,6 +291,8 @@ static void __init at91sam9261_initialize(void)
arm_pm_idle = at91sam9_idle;
arm_pm_restart = at91sam9_alt_restart;
+ at91_sysirq_mask_rtt(AT91SAM9261_BASE_RTT);
+
/* Register GPIO subsystem */
at91_gpio_init(at91sam9261_gpio, 3);
}
diff --git a/arch/arm/mach-at91/at91sam9263.c b/arch/arm/mach-at91/at91sam9263.c
index 6ce7d1850893..e6fed6253a7f 100644
--- a/arch/arm/mach-at91/at91sam9263.c
+++ b/arch/arm/mach-at91/at91sam9263.c
@@ -328,6 +328,9 @@ static void __init at91sam9263_initialize(void)
arm_pm_idle = at91sam9_idle;
arm_pm_restart = at91sam9_alt_restart;
+ at91_sysirq_mask_rtt(AT91SAM9263_BASE_RTT0);
+ at91_sysirq_mask_rtt(AT91SAM9263_BASE_RTT1);
+
/* Register GPIO subsystem */
at91_gpio_init(at91sam9263_gpio, 5);
}
diff --git a/arch/arm/mach-at91/at91sam9g45.c b/arch/arm/mach-at91/at91sam9g45.c
index ff662af77fee..9f7a97c84c12 100644
--- a/arch/arm/mach-at91/at91sam9g45.c
+++ b/arch/arm/mach-at91/at91sam9g45.c
@@ -378,6 +378,7 @@ static void __init at91sam9g45_initialize(void)
arm_pm_restart = at91sam9g45_restart;
at91_sysirq_mask_rtc(AT91SAM9G45_BASE_RTC);
+ at91_sysirq_mask_rtt(AT91SAM9G45_BASE_RTT);
/* Register GPIO subsystem */
at91_gpio_init(at91sam9g45_gpio, 5);
diff --git a/arch/arm/mach-at91/at91sam9rl.c b/arch/arm/mach-at91/at91sam9rl.c
index b5a8c9d81bc8..301e1728d353 100644
--- a/arch/arm/mach-at91/at91sam9rl.c
+++ b/arch/arm/mach-at91/at91sam9rl.c
@@ -295,6 +295,7 @@ static void __init at91sam9rl_initialize(void)
arm_pm_restart = at91sam9_alt_restart;
at91_sysirq_mask_rtc(AT91SAM9RL_BASE_RTC);
+ at91_sysirq_mask_rtt(AT91SAM9RL_BASE_RTT);
/* Register GPIO subsystem */
at91_gpio_init(at91sam9rl_gpio, 4);
diff --git a/arch/arm/mach-at91/generic.h b/arch/arm/mach-at91/generic.h
index 80269bda0dd7..26dee3ce9397 100644
--- a/arch/arm/mach-at91/generic.h
+++ b/arch/arm/mach-at91/generic.h
@@ -35,6 +35,7 @@ extern int __init at91_aic_of_init(struct device_node *node,
extern int __init at91_aic5_of_init(struct device_node *node,
struct device_node *parent);
extern void __init at91_sysirq_mask_rtc(u32 rtc_base);
+extern void __init at91_sysirq_mask_rtt(u32 rtt_base);
/* Timer */
diff --git a/arch/arm/mach-at91/sysirq_mask.c b/arch/arm/mach-at91/sysirq_mask.c
index ee3e22c66ce8..2ba694f9626b 100644
--- a/arch/arm/mach-at91/sysirq_mask.c
+++ b/arch/arm/mach-at91/sysirq_mask.c
@@ -21,6 +21,7 @@
*/
#include <linux/io.h>
+#include <mach/at91_rtt.h>
#include "generic.h"
@@ -45,3 +46,26 @@ void __init at91_sysirq_mask_rtc(u32 rtc_base)
iounmap(base);
}
+
+void __init at91_sysirq_mask_rtt(u32 rtt_base)
+{
+ void __iomem *base;
+ void __iomem *reg;
+ u32 mode;
+
+ base = ioremap(rtt_base, 16);
+ if (!base)
+ return;
+
+ reg = base + AT91_RTT_MR;
+
+ mode = readl_relaxed(reg);
+ if (mode & (AT91_RTT_ALMIEN | AT91_RTT_RTTINCIEN)) {
+ pr_info("AT91: Disabling rtt irq\n");
+ mode &= ~(AT91_RTT_ALMIEN | AT91_RTT_RTTINCIEN);
+ writel_relaxed(mode, reg);
+ (void)readl_relaxed(reg); /* flush */
+ }
+
+ iounmap(base);
+}