From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758534Ab3KOLK7 (ORCPT ); Fri, 15 Nov 2013 06:10:59 -0500 Received: from eusmtp01.atmel.com ([212.144.249.242]:36575 "EHLO eusmtp01.atmel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757286Ab3KOLKv (ORCPT ); Fri, 15 Nov 2013 06:10:51 -0500 Message-ID: <52860135.3030409@atmel.com> Date: Fri, 15 Nov 2013 12:10:45 +0100 From: Nicolas Ferre Organization: atmel User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.1.0 MIME-Version: 1.0 To: Johan Hovold CC: Jean-Christophe Plagniol-Villard , Andrew Victor , Alessandro Zummo , , , Subject: Re: [PATCH v3 2/3] ARM: at91: fix hanged boot due to early rtt-interrupt References: <1363025279-17615-1-git-send-email-jhovold@gmail.com> <1381917376-21107-1-git-send-email-jhovold@gmail.com> <1381917376-21107-3-git-send-email-jhovold@gmail.com> In-Reply-To: <1381917376-21107-3-git-send-email-jhovold@gmail.com> Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit X-Originating-IP: [10.161.30.18] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 Acked-by: Nicolas Ferre 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 > +#include > > #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); > +} > -- Nicolas Ferre