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    SubjectRe: [PATCH v3 4/4] OMAP3/4: iommu: adapt to runtime pm
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    Hi MyungJoo,

    On Wed, Nov 2, 2011 at 5:16 AM, MyungJoo Ham <myungjoo.ham@gmail.com> wrote:
    > On Wed, Nov 2, 2011 at 7:15 AM, Omar Ramirez Luna <omar.ramirez@ti.com> wrote:
    >> Use runtime PM functionality interfaced with hwmod enable/idle
    >> functions, to replace direct clock operations, reset and sysconfig
    >> handling.
    >>
    >> Tidspbridge uses a macro removed with this patch, for now the value
    >> is hardcoded to avoid breaking compilation.
    >>
    >> Signed-off-by: Omar Ramirez Luna <omar.ramirez@ti.com>
    >> ---
    >>  arch/arm/mach-omap2/iommu2.c                      |   17 --------
    >>  arch/arm/mach-omap2/omap-iommu.c                  |    1 -
    >>  arch/arm/plat-omap/include/plat/iommu.h           |    2 -
    >>  arch/arm/plat-omap/include/plat/iommu2.h          |    2 -
    >>  drivers/iommu/omap-iommu.c                        |   46 ++++++++-------------
    >>  drivers/staging/tidspbridge/core/tiomap3430_pwr.c |    2 +-
    >>  6 files changed, 19 insertions(+), 51 deletions(-)
    >>
    >> diff --git a/drivers/iommu/omap-iommu.c b/drivers/iommu/omap-iommu.c
    >> index bbbf747..3c55be0 100644
    >> --- a/drivers/iommu/omap-iommu.c
    >> +++ b/drivers/iommu/omap-iommu.c
    >> @@ -123,11 +123,11 @@ static int iommu_enable(struct omap_iommu *obj)
    >>        if (!arch_iommu)
    >>                return -ENODEV;
    >>
    >> -       clk_enable(obj->clk);
    >> +       pm_runtime_enable(obj->dev);
    >> +       pm_runtime_get_sync(obj->dev);
    >>
    >>        err = arch_iommu->enable(obj);
    >>
    >> -       clk_disable(obj->clk);
    >>        return err;
    >>  }
    >>
    >> @@ -136,11 +136,10 @@ static void iommu_disable(struct omap_iommu *obj)
    >>        if (!obj)
    >>                return;
    >>
    >> -       clk_enable(obj->clk);
    >> -
    >>        arch_iommu->disable(obj);
    >>
    >> -       clk_disable(obj->clk);
    >> +       pm_runtime_put_sync(obj->dev);
    >> +       pm_runtime_disable(obj->dev);
    >>  }
    > I'm just curious here... Is there any reason to do
    > pm_runtime_enable/disable at iommu_enable/iommu_disable which are
    > called by iommu_attach/detach?
    > I thought that normally, ideal locations of pm_runtime_enable/disable
    > for such devices are in probe/remove() because it assures that the
    > device is suspended after the probe.
    > It seems that the device might be kept on after probe and before the
    > first iommu_attach if it is default-on.

    The default state of these MMUs is on reset and needs to be deasserted
    to be used, but you're right, it makes more sense to move
    pm_runtime_enable/disable calls to probe/remove. I'll wait a bit, do
    this change and resubmit.

    Thanks for the comment,

    Omar
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