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| author | Colin Cross <ccross@android.com> | 2012-07-20 02:03:42 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2012-08-15 08:10:06 -0700 |
| commit | f95f7ae189b51123becde905e934954c86c8a0e2 (patch) | |
| tree | 4d799ea5e9df97b7b90ce238cf476f829443c13e | |
| parent | ea2ebaa71c978254c2a93bf561236aec8a167166 (diff) | |
| download | parrot-f95f7ae189b51123becde905e934954c86c8a0e2.tar.gz | |
ARM: 7477/1: vfp: Always save VFP state in vfp_pm_suspend on UP
commit 24b35521b8ddf088531258f06f681bb7b227bf47 upstream.
vfp_pm_suspend should save the VFP state in suspend after
any lazy context switch. If it only saves when the VFP is enabled,
the state can get lost when, on a UP system:
Thread 1 uses the VFP
Context switch occurs to thread 2, VFP is disabled but the
VFP context is not saved
Thread 2 initiates suspend
vfp_pm_suspend is called with the VFP disabled, and the unsaved
VFP context of Thread 1 in the registers
Modify vfp_pm_suspend to save the VFP context whenever
vfp_current_hw_state is not NULL.
Includes a fix from Ido Yariv <ido@wizery.com>, who pointed out that on
SMP systems, the state pointer can be pointing to a freed task struct if
a task exited on another cpu, fixed by using #ifndef CONFIG_SMP in the
new if clause.
Signed-off-by: Colin Cross <ccross@android.com>
Cc: Barry Song <bs14@csr.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Ido Yariv <ido@wizery.com>
Cc: Daniel Drake <dsd@laptop.org>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | arch/arm/vfp/vfpmodule.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/arch/arm/vfp/vfpmodule.c b/arch/arm/vfp/vfpmodule.c index da3b9292f9f0e..1ef803aa7a5c3 100644 --- a/arch/arm/vfp/vfpmodule.c +++ b/arch/arm/vfp/vfpmodule.c @@ -457,6 +457,12 @@ static int vfp_pm_suspend(void) /* disable, just in case */ fmxr(FPEXC, fmrx(FPEXC) & ~FPEXC_EN); + } else if (vfp_current_hw_state[ti->cpu]) { +#ifndef CONFIG_SMP + fmxr(FPEXC, fpexc | FPEXC_EN); + vfp_save_state(vfp_current_hw_state[ti->cpu], fpexc); + fmxr(FPEXC, fpexc); +#endif } /* clear any information we had about last context state */ |