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authorColin Cross <ccross@android.com>2012-07-20 02:03:42 +0100
committerRussell King <rmk+kernel@arm.linux.org.uk>2012-07-31 10:30:43 +0100
commit24b35521b8ddf088531258f06f681bb7b227bf47 (patch)
tree3edada314d07fb2d02dbda510ef0aeddf1e77733 /arch/arm/vfp
parenta84b895a2348f0dbff31b71ddf954f70a6cde368 (diff)
ARM: 7477/1: vfp: Always save VFP state in vfp_pm_suspend on UP
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> Cc: stable@vger.kernel.org Signed-off-by: Colin Cross <ccross@android.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm/vfp')
-rw-r--r--arch/arm/vfp/vfpmodule.c6
1 files changed, 6 insertions, 0 deletions
diff --git a/arch/arm/vfp/vfpmodule.c b/arch/arm/vfp/vfpmodule.c
index 9428006728f..fb849d044bd 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 */