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Date:   Mon, 1 Oct 2018 13:58:55 +0100
From:   Will Deacon <will.deacon@arm.com>
To:     Vivek Gautam <vivek.gautam@codeaurora.org>
Cc:     joro@8bytes.org, robh+dt@kernel.org, robin.murphy@arm.com,
        iommu@lists.linux-foundation.org, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org, alex.williamson@redhat.com,
        mark.rutland@arm.com, rjw@rjwysocki.net, robdclark@gmail.com,
        linux-pm@vger.kernel.org, freedreno@lists.freedesktop.org,
        sboyd@kernel.org, tfiga@chromium.org, jcrouse@codeaurora.org,
        sricharan@codeaurora.org, m.szyprowski@samsung.com,
        architt@codeaurora.org, linux-arm-msm@vger.kernel.org
Subject: Re: [PATCH v16 2/5] iommu/arm-smmu: Invoke pm_runtime during probe,
 add/remove device
Message-ID: <20181001125854.GB31488@arm.com>
References: <20180830144541.17740-1-vivek.gautam@codeaurora.org>
 <20180830144541.17740-3-vivek.gautam@codeaurora.org>
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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?

Will

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