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 <20180830144541.17740-3-vivek.gautam@codeaurora.org> <20181001125854.GB31488@arm.com>
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From:   Vivek Gautam <vivek.gautam@codeaurora.org>
Date:   Tue, 2 Oct 2018 09:44:54 +0530
Message-ID: <CAFp+6iGkudBtZFfk4ST+k9OMRSGgU=pzVGC4QaSmPb+Xkdp3Xw@mail.gmail.com>
Subject: Re: [PATCH v16 2/5] iommu/arm-smmu: Invoke pm_runtime during probe,
 add/remove device
To:     Will Deacon <will.deacon@arm.com>
Cc:     Joerg Roedel <joro@8bytes.org>, "robh+dt" <robh+dt@kernel.org>,
        Robin Murphy <robin.murphy@arm.com>,
        "list@263.net:IOMMU DRIVERS <iommu@lists.linux-foundation.org>, Joerg
        Roedel <joro@8bytes.org>," <iommu@lists.linux-foundation.org>,
        "open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" 
        <devicetree@vger.kernel.org>,
        open list <linux-kernel@vger.kernel.org>,
        alex.williamson@redhat.com, Mark Rutland <mark.rutland@arm.com>,
        "Rafael J. Wysocki" <rjw@rjwysocki.net>,
        Rob Clark <robdclark@gmail.com>,
        Linux PM <linux-pm@vger.kernel.org>,
        freedreno <freedreno@lists.freedesktop.org>, sboyd@kernel.org,
        Tomasz Figa <tfiga@chromium.org>,
        Jordan Crouse <jcrouse@codeaurora.org>,
        Sricharan R <sricharan@codeaurora.org>,
        Marek Szyprowski <m.szyprowski@samsung.com>,
        Archit Taneja <architt@codeaurora.org>,
        linux-arm-msm <linux-arm-msm@vger.kernel.org>
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Hi Will,

On Mon, Oct 1, 2018 at 6:29 PM Will Deacon <will.deacon@arm.com> wrote:
>
> Hi Vivek,
>
> On Thu, Aug 30, 2018 at 08:15:38PM +0530, Vivek Gautam wrote:
> > From: Sricharan R <sricharan@codeaurora.org>
> >
> > The smmu device probe/remove and add/remove master device callbacks
> > gets called when the smmu is not linked to its master, that is without
> > the context of the master device. So calling runtime apis in those places
> > separately.
> > Global locks are also initialized before enabling runtime pm as the
> > runtime_resume() calls device_reset() which does tlb_sync_global()
> > that ultimately requires locks to be initialized.
> >
> > Signed-off-by: Sricharan R <sricharan@codeaurora.org>
> > [vivek: Cleanup pm runtime calls]
> > Signed-off-by: Vivek Gautam <vivek.gautam@codeaurora.org>
> > Reviewed-by: Tomasz Figa <tfiga@chromium.org>
> > Tested-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
> > ---
> >  drivers/iommu/arm-smmu.c | 89 +++++++++++++++++++++++++++++++++++++++++++-----
> >  1 file changed, 81 insertions(+), 8 deletions(-)
>
> This doesn't apply on my tree[1], possibly because I've got Robin's non-strict
> invalidation queued there. However, that got me thinking -- how does this
> work in conjunction with the timer-based TLB invalidation? Do we need to
> rpm_{get,put} around flush_iotlb_all()? If so, do we still need the calls
> in map/unmap when non-strict mode is in use?

I haven't tested things with flush queues, but from what it looks like
both .flush_iotlb_all, and .iotlb_sync callbacks need rpm_get/put().
I will respin the patches.

Thanks
Vivek
>
> Will
>
> [1] https://git.kernel.org/pub/scm/linux/kernel/git/will/linux.git/log/?h=for-joerg/arm-smmu/updates


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