• Colin Cross's avatar
    ARM: 7477/1: vfp: Always save VFP state in vfp_pm_suspend on UP · 24b35521
    Colin Cross authored
    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: default avatarColin Cross <ccross@android.com>
    Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
    24b35521
vfpmodule.c 18.3 KB