Some hwmods may be idled/enabled directly from within the core
idle/suspend path. Since interrupts are already disabled here,
the mutex-based locking in hwmod can sleep and will cause
potential deadlocks.
To fix, add a hwmod flag HWMOD_NO_IDLE_LOCKING which indicates to the
hwmod core that no locking should be done during the idle/enable
paths for this hwmod.
Signed-off-by: Kevin Hilman <khil...@deeprootsystems.com>
---
arch/arm/mach-omap2/omap_hwmod.c | 16 ++++++++++++----
arch/arm/plat-omap/include/plat/omap_hwmod.h | 1 +
2 files changed, 13 insertions(+), 4 deletions(-)
diff --git a/arch/arm/mach-omap2/omap_hwmod.c b/arch/arm/mach-omap2/omap_hwmod.c
index 77fef90..1ee2fb2 100644
--- a/arch/arm/mach-omap2/omap_hwmod.c
+++ b/arch/arm/mach-omap2/omap_hwmod.c
@@ -1304,9 +1304,13 @@ int omap_hwmod_enable(struct omap_hwmod *oh)
if (!oh)
return -EINVAL;
- mutex_lock(&omap_hwmod_mutex);
+ if (!(oh->flags & HWMOD_NO_IDLE_LOCKING))
+ mutex_lock(&omap_hwmod_mutex);
+
r = _enable(oh);
- mutex_unlock(&omap_hwmod_mutex);
+
+ if (!(oh->flags & HWMOD_NO_IDLE_LOCKING))
+ mutex_unlock(&omap_hwmod_mutex);
return r;
}
@@ -1323,9 +1327,13 @@ int omap_hwmod_idle(struct omap_hwmod *oh)
if (!oh)
return -EINVAL;
- mutex_lock(&omap_hwmod_mutex);
+ if (!(oh->flags & HWMOD_NO_IDLE_LOCKING))
+ mutex_lock(&omap_hwmod_mutex);
+
_idle(oh);
- mutex_unlock(&omap_hwmod_mutex);
+
+ if (!(oh->flags & HWMOD_NO_IDLE_LOCKING))
+ mutex_unlock(&omap_hwmod_mutex);
return 0;
}
diff --git a/arch/arm/plat-omap/include/plat/omap_hwmod.h
b/arch/arm/plat-omap/include/plat/omap_hwmod.h
index 0eccc09..cc3f9a7 100644
--- a/arch/arm/plat-omap/include/plat/omap_hwmod.h
+++ b/arch/arm/plat-omap/include/plat/omap_hwmod.h
@@ -360,6 +360,7 @@ struct omap_hwmod_omap4_prcm {
#define HWMOD_NO_OCP_AUTOIDLE (1 << 4)
#define HWMOD_SET_DEFAULT_CLOCKACT (1 << 5)
#define HWMOD_NO_IDLEST (1 << 6)
+#define HWMOD_NO_IDLE_LOCKING (1 << 7)
/*
* omap_hwmod._int_flags definitions
--
1.7.0.2
--
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