From 6de714c21a8ea315fffba6a93bbe537f4c1bf4f0 Mon Sep 17 00:00:00 2001 From: Johan Hovold Date: Wed, 16 Oct 2013 11:56:14 +0200 Subject: ARM: at91: fix hanged boot due to early rtc-interrupt Make sure the RTC-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 RTC (but RM9200), for example, after a reset during an RTC-update or if an RTC-alarm goes off after 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 Signed-off-by: Nicolas Ferre Cc: stable@vger.kernel.org # 3.11.x --- arch/arm/mach-at91/include/mach/at91sam9n12.h | 5 +++++ arch/arm/mach-at91/include/mach/at91sam9x5.h | 5 +++++ arch/arm/mach-at91/include/mach/sama5d3.h | 5 +++++ 3 files changed, 15 insertions(+) (limited to 'arch/arm/mach-at91/include/mach') diff --git a/arch/arm/mach-at91/include/mach/at91sam9n12.h b/arch/arm/mach-at91/include/mach/at91sam9n12.h index d374b87c0459..0151bcf6163c 100644 --- a/arch/arm/mach-at91/include/mach/at91sam9n12.h +++ b/arch/arm/mach-at91/include/mach/at91sam9n12.h @@ -48,6 +48,11 @@ #define AT91SAM9N12_BASE_USART2 0xf8024000 #define AT91SAM9N12_BASE_USART3 0xf8028000 +/* + * System Peripherals + */ +#define AT91SAM9N12_BASE_RTC 0xfffffeb0 + /* * Internal Memory. */ diff --git a/arch/arm/mach-at91/include/mach/at91sam9x5.h b/arch/arm/mach-at91/include/mach/at91sam9x5.h index c75ee19b58d3..2fc76c49e97c 100644 --- a/arch/arm/mach-at91/include/mach/at91sam9x5.h +++ b/arch/arm/mach-at91/include/mach/at91sam9x5.h @@ -54,6 +54,11 @@ #define AT91SAM9X5_BASE_USART1 0xf8020000 #define AT91SAM9X5_BASE_USART2 0xf8024000 +/* + * System Peripherals + */ +#define AT91SAM9X5_BASE_RTC 0xfffffeb0 + /* * Internal Memory. */ diff --git a/arch/arm/mach-at91/include/mach/sama5d3.h b/arch/arm/mach-at91/include/mach/sama5d3.h index 31096a8aaf1d..25613d8c6dcd 100644 --- a/arch/arm/mach-at91/include/mach/sama5d3.h +++ b/arch/arm/mach-at91/include/mach/sama5d3.h @@ -72,6 +72,11 @@ #define SAMA5D3_BASE_USART2 0xf8020000 #define SAMA5D3_BASE_USART3 0xf8024000 +/* + * System Peripherals + */ +#define SAMA5D3_BASE_RTC 0xfffffeb0 + /* * Internal Memory */ -- cgit