[PATCH v3] ARM: vfp: Always save VFP state in vfp_pm_suspend

[Catalin Marinas]

On 4 May 2011 07:16, Barry Song <bs14 at csr.com> wrote:
> From: Colin Cross <ccross at android.com>
>
> vfp_pm_suspend should save the VFP state any time there is
> a last_VFP_context.  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 to allow lazy save and restore
>   Thread 2 initiates suspend
>   vfp_pm_suspend is called with the VFP disabled, but the
>      context has not been saved.
>
> Modify vfp_pm_suspend to save the VFP context whenever
> last_VFP_context is set.
>
> Signed-off-by: Colin Cross <ccross at android.com>
> Cc: Catalin Marinas <catalin.marinas at arm.com>
> Cc: Binghua Duan <binghua.duan at csr.com>
> Signed-off-by: Rongjun Ying <rongjun.ying at csr.com>
> Signed-off-by: Barry Song <21cnbao at gmail.com>
> ---
>  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 bbf3da0..a54c4d6 100644
> --- a/arch/arm/vfp/vfpmodule.c
> +++ b/arch/arm/vfp/vfpmodule.c
> @@ -392,6 +392,12 @@ static int vfp_pm_suspend(struct sys_device *dev, pm_message_t state)
>
>                /* disable, just in case */
>                fmxr(FPEXC, fmrx(FPEXC) & ~FPEXC_EN);
> +       } else {
> +               if (last_VFP_context[ti->cpu]) {
> +                       fmxr(FPEXC, fpexc | FPEXC_EN);
> +                       vfp_save_state(last_VFP_context[ti->cpu], fpexc);
> +                       fmxr(FPEXC, fpexc);
> +               }
>        }

I would use

        } else if () {

        }

to avoid another level of indentation.

Otherwise the patch looks fine to me (I haven't tested it).

Reviewed-by: Catalin Marinas <catalin.marinas at arm.com>