| Message ID | 1381917376-21107-2-git-send-email-jhovold@gmail.com |
|---|---|
| State | Accepted |
| Headers | show |
On 16/10/2013 11:56, Johan Hovold : > 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 <jhovold@gmail.com> Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com> and added to the at91-3.13-fixes-non-critical branch with the "stable" tag: Cc: stable@vger.kernel.org # 3.11.x Thanks a lot Johan. > --- > arch/arm/mach-at91/Makefile | 2 +- > arch/arm/mach-at91/at91sam9g45.c | 2 ++ > arch/arm/mach-at91/at91sam9n12.c | 6 ++++ > arch/arm/mach-at91/at91sam9rl.c | 2 ++ > arch/arm/mach-at91/at91sam9x5.c | 6 ++++ > arch/arm/mach-at91/generic.h | 1 + > 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 +++ > arch/arm/mach-at91/sama5d3.c | 6 ++++ > arch/arm/mach-at91/sysirq_mask.c | 47 +++++++++++++++++++++++++++ > 11 files changed, 86 insertions(+), 1 deletion(-) > create mode 100644 arch/arm/mach-at91/sysirq_mask.c > > diff --git a/arch/arm/mach-at91/Makefile b/arch/arm/mach-at91/Makefile > index aa33b0f..8879a41 100644 > --- a/arch/arm/mach-at91/Makefile > +++ b/arch/arm/mach-at91/Makefile > @@ -2,7 +2,7 @@ > # Makefile for the linux kernel. > # > > -obj-y := irq.o gpio.o setup.o > +obj-y := irq.o gpio.o setup.o sysirq_mask.o > obj-m := > obj-n := > obj- := > diff --git a/arch/arm/mach-at91/at91sam9g45.c b/arch/arm/mach-at91/at91sam9g45.c > index b9fe138..8d4da6d 100644 > --- a/arch/arm/mach-at91/at91sam9g45.c > +++ b/arch/arm/mach-at91/at91sam9g45.c > @@ -379,6 +379,8 @@ static void __init at91sam9g45_initialize(void) > arm_pm_idle = at91sam9_idle; > arm_pm_restart = at91sam9g45_restart; > > + at91_sysirq_mask_rtc(AT91SAM9G45_BASE_RTC); > + > /* Register GPIO subsystem */ > at91_gpio_init(at91sam9g45_gpio, 5); > } > diff --git a/arch/arm/mach-at91/at91sam9n12.c b/arch/arm/mach-at91/at91sam9n12.c > index c7d670d..4d6001c 100644 > --- a/arch/arm/mach-at91/at91sam9n12.c > +++ b/arch/arm/mach-at91/at91sam9n12.c > @@ -223,7 +223,13 @@ static void __init at91sam9n12_map_io(void) > at91_init_sram(0, AT91SAM9N12_SRAM_BASE, AT91SAM9N12_SRAM_SIZE); > } > > +static void __init at91sam9n12_initialize(void) > +{ > + at91_sysirq_mask_rtc(AT91SAM9N12_BASE_RTC); > +} > + > AT91_SOC_START(at91sam9n12) > .map_io = at91sam9n12_map_io, > .register_clocks = at91sam9n12_register_clocks, > + .init = at91sam9n12_initialize, > AT91_SOC_END > diff --git a/arch/arm/mach-at91/at91sam9rl.c b/arch/arm/mach-at91/at91sam9rl.c > index d4ec0d9..b5a8c9d 100644 > --- a/arch/arm/mach-at91/at91sam9rl.c > +++ b/arch/arm/mach-at91/at91sam9rl.c > @@ -294,6 +294,8 @@ static void __init at91sam9rl_initialize(void) > arm_pm_idle = at91sam9_idle; > arm_pm_restart = at91sam9_alt_restart; > > + at91_sysirq_mask_rtc(AT91SAM9RL_BASE_RTC); > + > /* Register GPIO subsystem */ > at91_gpio_init(at91sam9rl_gpio, 4); > } > diff --git a/arch/arm/mach-at91/at91sam9x5.c b/arch/arm/mach-at91/at91sam9x5.c > index 916e5a1..e8a2e07 100644 > --- a/arch/arm/mach-at91/at91sam9x5.c > +++ b/arch/arm/mach-at91/at91sam9x5.c > @@ -322,6 +322,11 @@ static void __init at91sam9x5_map_io(void) > at91_init_sram(0, AT91SAM9X5_SRAM_BASE, AT91SAM9X5_SRAM_SIZE); > } > > +static void __init at91sam9x5_initialize(void) > +{ > + at91_sysirq_mask_rtc(AT91SAM9X5_BASE_RTC); > +} > + > /* -------------------------------------------------------------------- > * Interrupt initialization > * -------------------------------------------------------------------- */ > @@ -329,4 +334,5 @@ static void __init at91sam9x5_map_io(void) > AT91_SOC_START(at91sam9x5) > .map_io = at91sam9x5_map_io, > .register_clocks = at91sam9x5_register_clocks, > + .init = at91sam9x5_initialize, > AT91_SOC_END > diff --git a/arch/arm/mach-at91/generic.h b/arch/arm/mach-at91/generic.h > index dc6e2f5..80269bd 100644 > --- a/arch/arm/mach-at91/generic.h > +++ b/arch/arm/mach-at91/generic.h > @@ -34,6 +34,7 @@ extern int __init at91_aic_of_init(struct device_node *node, > struct device_node *parent); > 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); > > > /* Timer */ > diff --git a/arch/arm/mach-at91/include/mach/at91sam9n12.h b/arch/arm/mach-at91/include/mach/at91sam9n12.h > index d374b87..0151bcf 100644 > --- a/arch/arm/mach-at91/include/mach/at91sam9n12.h > +++ b/arch/arm/mach-at91/include/mach/at91sam9n12.h > @@ -49,6 +49,11 @@ > #define AT91SAM9N12_BASE_USART3 0xf8028000 > > /* > + * System Peripherals > + */ > +#define AT91SAM9N12_BASE_RTC 0xfffffeb0 > + > +/* > * Internal Memory. > */ > #define AT91SAM9N12_SRAM_BASE 0x00300000 /* Internal SRAM base address */ > diff --git a/arch/arm/mach-at91/include/mach/at91sam9x5.h b/arch/arm/mach-at91/include/mach/at91sam9x5.h > index c75ee19..2fc76c4 100644 > --- a/arch/arm/mach-at91/include/mach/at91sam9x5.h > +++ b/arch/arm/mach-at91/include/mach/at91sam9x5.h > @@ -55,6 +55,11 @@ > #define AT91SAM9X5_BASE_USART2 0xf8024000 > > /* > + * System Peripherals > + */ > +#define AT91SAM9X5_BASE_RTC 0xfffffeb0 > + > +/* > * Internal Memory. > */ > #define AT91SAM9X5_SRAM_BASE 0x00300000 /* Internal SRAM base address */ > diff --git a/arch/arm/mach-at91/include/mach/sama5d3.h b/arch/arm/mach-at91/include/mach/sama5d3.h > index 31096a8..25613d8 100644 > --- a/arch/arm/mach-at91/include/mach/sama5d3.h > +++ b/arch/arm/mach-at91/include/mach/sama5d3.h > @@ -73,6 +73,11 @@ > #define SAMA5D3_BASE_USART3 0xf8024000 > > /* > + * System Peripherals > + */ > +#define SAMA5D3_BASE_RTC 0xfffffeb0 > + > +/* > * Internal Memory > */ > #define SAMA5D3_SRAM_BASE 0x00300000 /* Internal SRAM base address */ > diff --git a/arch/arm/mach-at91/sama5d3.c b/arch/arm/mach-at91/sama5d3.c > index 4012797..3ea8642 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 > diff --git a/arch/arm/mach-at91/sysirq_mask.c b/arch/arm/mach-at91/sysirq_mask.c > new file mode 100644 > index 0000000..ee3e22c > --- /dev/null > +++ b/arch/arm/mach-at91/sysirq_mask.c > @@ -0,0 +1,47 @@ > +/* > + * sysirq_mask.c - System-interrupt masking > + * > + * Copyright (C) 2013 Johan Hovold <jhovold@gmail.com> > + * > + * Functions to disable system interrupts from backup-powered peripherals. > + * > + * The RTC and RTT-peripherals are generally powered by backup power (VDDBU) > + * and are not reset on wake-up, user, watchdog or software reset. This means > + * that their interrupts may be enabled during early boot (e.g. after a user > + * reset). > + * > + * As the RTC and RTT share the system-interrupt line with the PIT, an > + * interrupt occurring before a handler has been installed would lead to the > + * system interrupt being disabled and prevent the system from booting. > + * > + * This program is free software; you can redistribute it and/or modify > + * it under the terms of the GNU General Public License as published by > + * the Free Software Foundation; either version 2 of the License, or > + * (at your option) any later version. > + */ > + > +#include <linux/io.h> > + > +#include "generic.h" > + > +#define AT91_RTC_IDR 0x24 /* Interrupt Disable Register */ > +#define AT91_RTC_IMR 0x28 /* Interrupt Mask Register */ > + > +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 */ > + } > + > + iounmap(base); > +} >
diff --git a/arch/arm/mach-at91/Makefile b/arch/arm/mach-at91/Makefile index aa33b0f..8879a41 100644 --- a/arch/arm/mach-at91/Makefile +++ b/arch/arm/mach-at91/Makefile @@ -2,7 +2,7 @@ # Makefile for the linux kernel. # -obj-y := irq.o gpio.o setup.o +obj-y := irq.o gpio.o setup.o sysirq_mask.o obj-m := obj-n := obj- := diff --git a/arch/arm/mach-at91/at91sam9g45.c b/arch/arm/mach-at91/at91sam9g45.c index b9fe138..8d4da6d 100644 --- a/arch/arm/mach-at91/at91sam9g45.c +++ b/arch/arm/mach-at91/at91sam9g45.c @@ -379,6 +379,8 @@ static void __init at91sam9g45_initialize(void) arm_pm_idle = at91sam9_idle; arm_pm_restart = at91sam9g45_restart; + at91_sysirq_mask_rtc(AT91SAM9G45_BASE_RTC); + /* Register GPIO subsystem */ at91_gpio_init(at91sam9g45_gpio, 5); } diff --git a/arch/arm/mach-at91/at91sam9n12.c b/arch/arm/mach-at91/at91sam9n12.c index c7d670d..4d6001c 100644 --- a/arch/arm/mach-at91/at91sam9n12.c +++ b/arch/arm/mach-at91/at91sam9n12.c @@ -223,7 +223,13 @@ static void __init at91sam9n12_map_io(void) at91_init_sram(0, AT91SAM9N12_SRAM_BASE, AT91SAM9N12_SRAM_SIZE); } +static void __init at91sam9n12_initialize(void) +{ + at91_sysirq_mask_rtc(AT91SAM9N12_BASE_RTC); +} + AT91_SOC_START(at91sam9n12) .map_io = at91sam9n12_map_io, .register_clocks = at91sam9n12_register_clocks, + .init = at91sam9n12_initialize, AT91_SOC_END diff --git a/arch/arm/mach-at91/at91sam9rl.c b/arch/arm/mach-at91/at91sam9rl.c index d4ec0d9..b5a8c9d 100644 --- a/arch/arm/mach-at91/at91sam9rl.c +++ b/arch/arm/mach-at91/at91sam9rl.c @@ -294,6 +294,8 @@ static void __init at91sam9rl_initialize(void) arm_pm_idle = at91sam9_idle; arm_pm_restart = at91sam9_alt_restart; + at91_sysirq_mask_rtc(AT91SAM9RL_BASE_RTC); + /* Register GPIO subsystem */ at91_gpio_init(at91sam9rl_gpio, 4); } diff --git a/arch/arm/mach-at91/at91sam9x5.c b/arch/arm/mach-at91/at91sam9x5.c index 916e5a1..e8a2e07 100644 --- a/arch/arm/mach-at91/at91sam9x5.c +++ b/arch/arm/mach-at91/at91sam9x5.c @@ -322,6 +322,11 @@ static void __init at91sam9x5_map_io(void) at91_init_sram(0, AT91SAM9X5_SRAM_BASE, AT91SAM9X5_SRAM_SIZE); } +static void __init at91sam9x5_initialize(void) +{ + at91_sysirq_mask_rtc(AT91SAM9X5_BASE_RTC); +} + /* -------------------------------------------------------------------- * Interrupt initialization * -------------------------------------------------------------------- */ @@ -329,4 +334,5 @@ static void __init at91sam9x5_map_io(void) AT91_SOC_START(at91sam9x5) .map_io = at91sam9x5_map_io, .register_clocks = at91sam9x5_register_clocks, + .init = at91sam9x5_initialize, AT91_SOC_END diff --git a/arch/arm/mach-at91/generic.h b/arch/arm/mach-at91/generic.h index dc6e2f5..80269bd 100644 --- a/arch/arm/mach-at91/generic.h +++ b/arch/arm/mach-at91/generic.h @@ -34,6 +34,7 @@ extern int __init at91_aic_of_init(struct device_node *node, struct device_node *parent); 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); /* Timer */ diff --git a/arch/arm/mach-at91/include/mach/at91sam9n12.h b/arch/arm/mach-at91/include/mach/at91sam9n12.h index d374b87..0151bcf 100644 --- a/arch/arm/mach-at91/include/mach/at91sam9n12.h +++ b/arch/arm/mach-at91/include/mach/at91sam9n12.h @@ -49,6 +49,11 @@ #define AT91SAM9N12_BASE_USART3 0xf8028000 /* + * System Peripherals + */ +#define AT91SAM9N12_BASE_RTC 0xfffffeb0 + +/* * Internal Memory. */ #define AT91SAM9N12_SRAM_BASE 0x00300000 /* Internal SRAM base address */ diff --git a/arch/arm/mach-at91/include/mach/at91sam9x5.h b/arch/arm/mach-at91/include/mach/at91sam9x5.h index c75ee19..2fc76c4 100644 --- a/arch/arm/mach-at91/include/mach/at91sam9x5.h +++ b/arch/arm/mach-at91/include/mach/at91sam9x5.h @@ -55,6 +55,11 @@ #define AT91SAM9X5_BASE_USART2 0xf8024000 /* + * System Peripherals + */ +#define AT91SAM9X5_BASE_RTC 0xfffffeb0 + +/* * Internal Memory. */ #define AT91SAM9X5_SRAM_BASE 0x00300000 /* Internal SRAM base address */ diff --git a/arch/arm/mach-at91/include/mach/sama5d3.h b/arch/arm/mach-at91/include/mach/sama5d3.h index 31096a8..25613d8 100644 --- a/arch/arm/mach-at91/include/mach/sama5d3.h +++ b/arch/arm/mach-at91/include/mach/sama5d3.h @@ -73,6 +73,11 @@ #define SAMA5D3_BASE_USART3 0xf8024000 /* + * System Peripherals + */ +#define SAMA5D3_BASE_RTC 0xfffffeb0 + +/* * Internal Memory */ #define SAMA5D3_SRAM_BASE 0x00300000 /* Internal SRAM base address */ diff --git a/arch/arm/mach-at91/sama5d3.c b/arch/arm/mach-at91/sama5d3.c index 4012797..3ea8642 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 diff --git a/arch/arm/mach-at91/sysirq_mask.c b/arch/arm/mach-at91/sysirq_mask.c new file mode 100644 index 0000000..ee3e22c --- /dev/null +++ b/arch/arm/mach-at91/sysirq_mask.c @@ -0,0 +1,47 @@ +/* + * sysirq_mask.c - System-interrupt masking + * + * Copyright (C) 2013 Johan Hovold <jhovold@gmail.com> + * + * Functions to disable system interrupts from backup-powered peripherals. + * + * The RTC and RTT-peripherals are generally powered by backup power (VDDBU) + * and are not reset on wake-up, user, watchdog or software reset. This means + * that their interrupts may be enabled during early boot (e.g. after a user + * reset). + * + * As the RTC and RTT share the system-interrupt line with the PIT, an + * interrupt occurring before a handler has been installed would lead to the + * system interrupt being disabled and prevent the system from booting. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + */ + +#include <linux/io.h> + +#include "generic.h" + +#define AT91_RTC_IDR 0x24 /* Interrupt Disable Register */ +#define AT91_RTC_IMR 0x28 /* Interrupt Mask Register */ + +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 */ + } + + iounmap(base); +}
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 <jhovold@gmail.com> --- arch/arm/mach-at91/Makefile | 2 +- arch/arm/mach-at91/at91sam9g45.c | 2 ++ arch/arm/mach-at91/at91sam9n12.c | 6 ++++ arch/arm/mach-at91/at91sam9rl.c | 2 ++ arch/arm/mach-at91/at91sam9x5.c | 6 ++++ arch/arm/mach-at91/generic.h | 1 + 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 +++ arch/arm/mach-at91/sama5d3.c | 6 ++++ arch/arm/mach-at91/sysirq_mask.c | 47 +++++++++++++++++++++++++++ 11 files changed, 86 insertions(+), 1 deletion(-) create mode 100644 arch/arm/mach-at91/sysirq_mask.c