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* [patch added to 3.12-stable] clocksource/drivers/sun4i: Clear interrupts after stopping timer in probe function
@ 2016-09-29  9:06 Jiri Slaby
  2016-09-29  9:06 ` [patch added to 3.12-stable] powerpc/mm: Don't alias user region to other regions below PAGE_OFFSET Jiri Slaby
                   ` (41 more replies)
  0 siblings, 42 replies; 44+ messages in thread
From: Jiri Slaby @ 2016-09-29  9:06 UTC (permalink / raw)
  To: stable; +Cc: Chen-Yu Tsai, Daniel Lezcano, Jiri Slaby

From: Chen-Yu Tsai <wens@csie.org>

This patch has been added to the 3.12 stable tree. If you have any
objections, please let us know.

===============

commit b53e7d000d9e6e9fd2c6eb6b82d2783c67fd599e upstream.

The bootloader (U-boot) sometimes uses this timer for various delays.
It uses it as a ongoing counter, and does comparisons on the current
counter value. The timer counter is never stopped.

In some cases when the user interacts with the bootloader, or lets
it idle for some time before loading Linux, the timer may expire,
and an interrupt will be pending. This results in an unexpected
interrupt when the timer interrupt is enabled by the kernel, at
which point the event_handler isn't set yet. This results in a NULL
pointer dereference exception, panic, and no way to reboot.

Clear any pending interrupts after we stop the timer in the probe
function to avoid this.

Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
---
 drivers/clocksource/sun4i_timer.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/drivers/clocksource/sun4i_timer.c b/drivers/clocksource/sun4i_timer.c
index 4fe6ac85ea1d..b4b0c6a2a00d 100644
--- a/drivers/clocksource/sun4i_timer.c
+++ b/drivers/clocksource/sun4i_timer.c
@@ -118,12 +118,16 @@ static struct clock_event_device sun4i_clockevent = {
 	.set_next_event = sun4i_clkevt_next_event,
 };
 
+static void sun4i_timer_clear_interrupt(void)
+{
+	writel(TIMER_IRQ_EN(0), timer_base + TIMER_IRQ_ST_REG);
+}
 
 static irqreturn_t sun4i_timer_interrupt(int irq, void *dev_id)
 {
 	struct clock_event_device *evt = (struct clock_event_device *)dev_id;
 
-	writel(0x1, timer_base + TIMER_IRQ_ST_REG);
+	sun4i_timer_clear_interrupt();
 	evt->event_handler(evt);
 
 	return IRQ_HANDLED;
@@ -177,6 +181,9 @@ static void __init sun4i_timer_init(struct device_node *node)
 	writel(TIMER_CTL_CLK_SRC(TIMER_CTL_CLK_SRC_OSC24M),
 	       timer_base + TIMER_CTL_REG(0));
 
+	/* clear timer0 interrupt */
+	sun4i_timer_clear_interrupt();
+
 	sun4i_clockevent.cpumask = cpumask_of(0);
 
 	clockevents_config_and_register(&sun4i_clockevent, rate, 0x1,
-- 
2.10.0


^ permalink raw reply related	[flat|nested] 44+ messages in thread

end of thread, other threads:[~2016-09-29  9:07 UTC | newest]

Thread overview: 44+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2016-09-29  9:06 [patch added to 3.12-stable] clocksource/drivers/sun4i: Clear interrupts after stopping timer in probe function Jiri Slaby
2016-09-29  9:06 ` [patch added to 3.12-stable] powerpc/mm: Don't alias user region to other regions below PAGE_OFFSET Jiri Slaby
2016-09-29  9:06 ` [patch added to 3.12-stable] NFSv4.x: Fix a refcount leak in nfs_callback_up_net Jiri Slaby
2016-09-29  9:06 ` [patch added to 3.12-stable] dm flakey: fix reads to be issued if drop_writes configured Jiri Slaby
2016-09-29  9:06 ` [patch added to 3.12-stable] x86/paravirt: Do not trace _paravirt_ident_*() functions Jiri Slaby
2016-09-29  9:06 ` [patch added to 3.12-stable] kvm-arm: Unmap shadow pagetables properly Jiri Slaby
2016-09-29  9:06 ` [patch added to 3.12-stable] iio: accel: kxsd9: Fix raw read return Jiri Slaby
2016-09-29  9:06 ` [patch added to 3.12-stable] iio: accel: kxsd9: Fix scaling bug Jiri Slaby
2016-09-29  9:06 ` [patch added to 3.12-stable] USB: serial: simple: add support for another Infineon flashloader Jiri Slaby
2016-09-29  9:06 ` [patch added to 3.12-stable] usb: renesas_usbhs: fix clearing the {BRDY,BEMP}STS condition Jiri Slaby
2016-09-29  9:06 ` [patch added to 3.12-stable] USB: change bInterval default to 10 ms Jiri Slaby
2016-09-29  9:06 ` [patch added to 3.12-stable] ARM: OMAP3: hwmod data: Add sysc information for DSI Jiri Slaby
2016-09-29  9:06 ` [patch added to 3.12-stable] arm64: spinlocks: implement smp_mb__before_spinlock() as smp_mb() Jiri Slaby
2016-09-29  9:06 ` [patch added to 3.12-stable] crypto: cryptd - initialize child shash_desc on import Jiri Slaby
2016-09-29  9:06 ` [patch added to 3.12-stable] microblaze: fix __get_user() Jiri Slaby
2016-09-29  9:06 ` [patch added to 3.12-stable] avr32: fix copy_from_user() Jiri Slaby
2016-09-29  9:06 ` [patch added to 3.12-stable] microblaze: " Jiri Slaby
2016-09-29  9:06 ` [patch added to 3.12-stable] fix minor infoleak in get_user_ex() Jiri Slaby
2016-09-29  9:06 ` [patch added to 3.12-stable] mn10300: failing __get_user() and get_user() should zero Jiri Slaby
2016-09-29  9:06 ` [patch added to 3.12-stable] m32r: fix __get_user() Jiri Slaby
2016-09-29  9:06 ` [patch added to 3.12-stable] sh64: failing __get_user() should zero Jiri Slaby
2016-09-29  9:06 ` [patch added to 3.12-stable] score: fix __get_user/get_user Jiri Slaby
2016-09-29  9:06 ` [patch added to 3.12-stable] s390: get_user() should zero on failure Jiri Slaby
2016-09-29  9:06 ` [patch added to 3.12-stable] ARC: uaccess: get_user to zero out dest in cause of fault Jiri Slaby
2016-09-29  9:06   ` Jiri Slaby
2016-09-29  9:06 ` [patch added to 3.12-stable] asm-generic: make get_user() clear the destination on errors Jiri Slaby
2016-09-29  9:06 ` [patch added to 3.12-stable] frv: fix clear_user() Jiri Slaby
2016-09-29  9:06 ` [patch added to 3.12-stable] cris: buggered copy_from_user/copy_to_user/clear_user Jiri Slaby
2016-09-29  9:06 ` [patch added to 3.12-stable] blackfin: fix copy_from_user() Jiri Slaby
2016-09-29  9:06 ` [patch added to 3.12-stable] score: fix copy_from_user() and friends Jiri Slaby
2016-09-29  9:06 ` [patch added to 3.12-stable] sh: fix copy_from_user() Jiri Slaby
2016-09-29  9:06 ` [patch added to 3.12-stable] hexagon: fix strncpy_from_user() error return Jiri Slaby
2016-09-29  9:06 ` [patch added to 3.12-stable] mips: copy_from_user() must zero the destination on access_ok() failure Jiri Slaby
2016-09-29  9:06 ` [patch added to 3.12-stable] asm-generic: make copy_from_user() zero the destination properly Jiri Slaby
2016-09-29  9:06 ` [patch added to 3.12-stable] alpha: fix copy_from_user() Jiri Slaby
2016-09-29  9:06 ` [patch added to 3.12-stable] metag: copy_from_user() should zero the destination on access_ok() failure Jiri Slaby
2016-09-29  9:06 ` [patch added to 3.12-stable] parisc: fix copy_from_user() Jiri Slaby
2016-09-29  9:06 ` [patch added to 3.12-stable] openrisc: " Jiri Slaby
2016-09-29  9:06 ` [patch added to 3.12-stable] mn10300: copy_from_user() should zero on access_ok() failure Jiri Slaby
2016-09-29  9:06 ` [patch added to 3.12-stable] sparc32: fix copy_from_user() Jiri Slaby
2016-09-29  9:06 ` [patch added to 3.12-stable] ppc32: " Jiri Slaby
2016-09-29  9:06 ` [patch added to 3.12-stable] ia64: copy_from_user() should zero the destination on access_ok() failure Jiri Slaby
2016-09-29  9:06 ` [patch added to 3.12-stable] avr32: fix 'undefined reference to `___copy_from_user' Jiri Slaby
2016-09-29  9:06 ` [patch added to 3.12-stable] openrisc: fix the fix of copy_from_user() Jiri Slaby

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