diff options
author | Colin Cross <ccross@android.com> | 2012-07-20 02:03:42 +0100 |
---|---|---|
committer | Ben Hutchings <ben@decadent.org.uk> | 2012-08-10 00:25:05 +0100 |
commit | cdab6eed39be615703f582831765e14fb0452842 (patch) | |
tree | 6343f638b4c32fb76b90dd7b29acef476e6d1ba5 /arch | |
parent | fc257bc543a3b08545e2332574a12893f0e54c85 (diff) |
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.
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: Colin Cross <ccross@android.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Diffstat (limited to 'arch')
-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 61e11cea9f75..ad83dadd151d 100644 --- a/arch/arm/vfp/vfpmodule.c +++ b/arch/arm/vfp/vfpmodule.c @@ -453,6 +453,12 @@ 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 */ |