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/sama5d3.c | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'arch/arm/mach-at91/sama5d3.c') diff --git a/arch/arm/mach-at91/sama5d3.c b/arch/arm/mach-at91/sama5d3.c index 401279715ab1..3ea86428ee09 100644 --- a/arch/arm/mach-at91/sama5d3.c +++ b/arch/arm/mach-at91/sama5d3.c @@ -371,7 +371,13 @@ static void __init sama5d3_map_io(void) at91_init_sram(0, SAMA5D3_SRAM_BASE, SAMA5D3_SRAM_SIZE); } +static void __init sama5d3_initialize(void) +{ + at91_sysirq_mask_rtc(SAMA5D3_BASE_RTC); +} + AT91_SOC_START(sama5d3) .map_io = sama5d3_map_io, .register_clocks = sama5d3_register_clocks, + .init = sama5d3_initialize, AT91_SOC_END -- cgit v1.2.1