commit
94c4c79f2f1acca6e69a50bff5a7d9027509c16b upstream.
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
at91_extern_irq = (1 << AT91SAM9260_ID_IRQ0) | (1 << AT91SAM9260_ID_IRQ1)
| (1 << AT91SAM9260_ID_IRQ2);
+ at91_sysirq_mask_rtt(AT91SAM9260_BASE_RTT);
+
/* Register GPIO subsystem */
at91_gpio_init(at91sam9260_gpio, 3);
}
at91_extern_irq = (1 << AT91SAM9261_ID_IRQ0) | (1 << AT91SAM9261_ID_IRQ1)
| (1 << AT91SAM9261_ID_IRQ2);
+ at91_sysirq_mask_rtt(AT91SAM9261_BASE_RTT);
+
/* Register GPIO subsystem */
at91_gpio_init(at91sam9261_gpio, 3);
}
arm_pm_restart = at91sam9_alt_restart;
at91_extern_irq = (1 << AT91SAM9263_ID_IRQ0) | (1 << AT91SAM9263_ID_IRQ1);
+ at91_sysirq_mask_rtt(AT91SAM9263_BASE_RTT0);
+ at91_sysirq_mask_rtt(AT91SAM9263_BASE_RTT1);
+
/* Register GPIO subsystem */
at91_gpio_init(at91sam9263_gpio, 5);
}
at91_extern_irq = (1 << AT91SAM9G45_ID_IRQ0);
at91_sysirq_mask_rtc(AT91SAM9G45_BASE_RTC);
+ at91_sysirq_mask_rtt(AT91SAM9G45_BASE_RTT);
/* Register GPIO subsystem */
at91_gpio_init(at91sam9g45_gpio, 5);
at91_extern_irq = (1 << AT91SAM9RL_ID_IRQ0);
at91_sysirq_mask_rtc(AT91SAM9RL_BASE_RTC);
+ at91_sysirq_mask_rtt(AT91SAM9RL_BASE_RTT);
/* Register GPIO subsystem */
at91_gpio_init(at91sam9rl_gpio, 4);
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 */
*/
#include <linux/io.h>
+#include <mach/at91_rtt.h>
#include "generic.h"
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);
+}