| Message ID | 1381917376-21107-3-git-send-email-jhovold@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 16/10/2013 11:56, Johan Hovold : > 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> 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 for your patience, bye, > --- > arch/arm/mach-at91/at91sam9260.c | 2 ++ > arch/arm/mach-at91/at91sam9261.c | 2 ++ > arch/arm/mach-at91/at91sam9263.c | 3 +++ > arch/arm/mach-at91/at91sam9g45.c | 1 + > arch/arm/mach-at91/at91sam9rl.c | 1 + > arch/arm/mach-at91/generic.h | 1 + > arch/arm/mach-at91/sysirq_mask.c | 24 ++++++++++++++++++++++++ > 7 files changed, 34 insertions(+) > > diff --git a/arch/arm/mach-at91/at91sam9260.c b/arch/arm/mach-at91/at91sam9260.c > index 5de6074..ae10d14 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 0e07932..e761e74 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 962768b..ad02281 100644 > --- a/arch/arm/mach-at91/at91sam9263.c > +++ b/arch/arm/mach-at91/at91sam9263.c > @@ -330,6 +330,9 @@ 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 8d4da6d..88e6f7b 100644 > --- a/arch/arm/mach-at91/at91sam9g45.c > +++ b/arch/arm/mach-at91/at91sam9g45.c > @@ -380,6 +380,7 @@ 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 b5a8c9d..301e172 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 80269bd..26dee3c 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 ee3e22c..2ba694f 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); > +} >
diff --git a/arch/arm/mach-at91/at91sam9260.c b/arch/arm/mach-at91/at91sam9260.c index 5de6074..ae10d14 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 0e07932..e761e74 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 962768b..ad02281 100644 --- a/arch/arm/mach-at91/at91sam9263.c +++ b/arch/arm/mach-at91/at91sam9263.c @@ -330,6 +330,9 @@ 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 8d4da6d..88e6f7b 100644 --- a/arch/arm/mach-at91/at91sam9g45.c +++ b/arch/arm/mach-at91/at91sam9g45.c @@ -380,6 +380,7 @@ 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 b5a8c9d..301e172 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 80269bd..26dee3c 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 ee3e22c..2ba694f 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); +}
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> --- arch/arm/mach-at91/at91sam9260.c | 2 ++ arch/arm/mach-at91/at91sam9261.c | 2 ++ arch/arm/mach-at91/at91sam9263.c | 3 +++ arch/arm/mach-at91/at91sam9g45.c | 1 + arch/arm/mach-at91/at91sam9rl.c | 1 + arch/arm/mach-at91/generic.h | 1 + arch/arm/mach-at91/sysirq_mask.c | 24 ++++++++++++++++++++++++ 7 files changed, 34 insertions(+)