3.18-stable patches

added patches:
	arm-imx6q-cpuidle-fix-bug-that-cpu-might-not-wake-up-at-expected-time.patch

diff --git a/queue-3.18/arm-imx6q-cpuidle-fix-bug-that-cpu-might-not-wake-up-at-expected-time.patch b/queue-3.18/arm-imx6q-cpuidle-fix-bug-that-cpu-might-not-wake-up-at-expected-time.patch
new file mode 100644 (file)
index 0000000..3d74f44
--- /dev/null
+++ b/queue-3.18/arm-imx6q-cpuidle-fix-bug-that-cpu-might-not-wake-up-at-expected-time.patch
@@ -0,0 +1,77 @@
+From 91740fc8242b4f260cfa4d4536d8551804777fae Mon Sep 17 00:00:00 2001
+From: Kohji Okuno <okuno.kohji@jp.panasonic.com>
+Date: Tue, 26 Feb 2019 11:34:13 +0900
+Subject: ARM: imx6q: cpuidle: fix bug that CPU might not wake up at expected time
+
+From: Kohji Okuno <okuno.kohji@jp.panasonic.com>
+
+commit 91740fc8242b4f260cfa4d4536d8551804777fae upstream.
+
+In the current cpuidle implementation for i.MX6q, the CPU that sets
+'WAIT_UNCLOCKED' and the CPU that returns to 'WAIT_CLOCKED' are always
+the same. While the CPU that sets 'WAIT_UNCLOCKED' is in IDLE state of
+"WAIT", if the other CPU wakes up and enters IDLE state of "WFI"
+istead of "WAIT", this CPU can not wake up at expired time.
+ Because, in the case of "WFI", the CPU must be waked up by the local
+timer interrupt. But, while 'WAIT_UNCLOCKED' is set, the local timer
+is stopped, when all CPUs execute "wfi" instruction. As a result, the
+local timer interrupt is not fired.
+ In this situation, this CPU will wake up by IRQ different from local
+timer. (e.g. broacast timer)
+
+So, this fix changes CPU to return to 'WAIT_CLOCKED'.
+
+Signed-off-by: Kohji Okuno <okuno.kohji@jp.panasonic.com>
+Fixes: e5f9dec8ff5f ("ARM: imx6q: support WAIT mode using cpuidle")
+Cc: <stable@vger.kernel.org>
+Signed-off-by: Shawn Guo <shawnguo@kernel.org>
+Signed-off-by: Kohji Okuno <okuno.kohji@jp.panasonic.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+---
+ arch/arm/mach-imx/cpuidle-imx6q.c |   27 ++++++++++-----------------
+ 1 file changed, 10 insertions(+), 17 deletions(-)
+
+--- a/arch/arm/mach-imx/cpuidle-imx6q.c
++++ b/arch/arm/mach-imx/cpuidle-imx6q.c
+@@ -15,30 +15,23 @@
+ #include "cpuidle.h"
+ #include "hardware.h"
+ 
+-static atomic_t master = ATOMIC_INIT(0);
+-static DEFINE_SPINLOCK(master_lock);
++static int num_idle_cpus = 0;
++static DEFINE_SPINLOCK(cpuidle_lock);
+ 
+ static int imx6q_enter_wait(struct cpuidle_device *dev,
+                           struct cpuidle_driver *drv, int index)
+ {
+-      if (atomic_inc_return(&master) == num_online_cpus()) {
+-              /*
+-               * With this lock, we prevent other cpu to exit and enter
+-               * this function again and become the master.
+-               */
+-              if (!spin_trylock(&master_lock))
+-                      goto idle;
++      spin_lock(&cpuidle_lock);
++      if (++num_idle_cpus == num_online_cpus())
+               imx6q_set_lpm(WAIT_UNCLOCKED);
+-              cpu_do_idle();
+-              imx6q_set_lpm(WAIT_CLOCKED);
+-              spin_unlock(&master_lock);
+-              goto done;
+-      }
++      spin_unlock(&cpuidle_lock);
+ 
+-idle:
+       cpu_do_idle();
+-done:
+-      atomic_dec(&master);
++
++      spin_lock(&cpuidle_lock);
++      if (num_idle_cpus-- == num_online_cpus())
++              imx6q_set_lpm(WAIT_CLOCKED);
++      spin_unlock(&cpuidle_lock);
+ 
+       return index;
+ }

diff --git a/queue-3.18/series b/queue-3.18/series
index 01e90f8119bfc188fb5a8a92a28e28ccf7772dc7..e4609a9be23297ade38a6eed6c450eb682260cf7 100644 (file)
--- a/queue-3.18/series
+++ b/queue-3.18/series
@@ -46,3 +46,4 @@ fs-proc-proc_sysctl.c-fix-null-pointer-dereference-in-put_links.patch
 gpio-adnp-fix-testing-wrong-value-in-adnp_gpio_direction_input.patch
 kvm-reject-device-ioctls-from-processes-other-than-the-vm-s-creator.patch
 xhci-fix-port-resume-done-detection-for-ss-ports-with-lpm-enabled.patch
+arm-imx6q-cpuidle-fix-bug-that-cpu-might-not-wake-up-at-expected-time.patch