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From:   John Stultz <john.stultz@linaro.org>
Date:   Mon, 26 Jul 2021 12:03:30 -0700
Message-ID: <CALAqxLVLV8cLVTOFPZmzKeDaG0qFoQ6H=+2a8LaAvgs+4EYMfw@mail.gmail.com>
Subject: Re: [PATCH] drm/msm: Fix display fault handling
To:     Rob Clark <robdclark@gmail.com>
Cc:     dri-devel <dri-devel@lists.freedesktop.org>,
        Rob Clark <robdclark@chromium.org>,
        Dmitry Baryshkov <dmitry.baryshkov@linaro.org>,
        Yassine Oudjana <y.oudjana@protonmail.com>,
        Sean Paul <sean@poorly.run>, David Airlie <airlied@linux.ie>,
        Daniel Vetter <daniel@ffwll.ch>,
        Bjorn Andersson <bjorn.andersson@linaro.org>,
        Jordan Crouse <jordan@cosmicpenguin.net>,
        "open list:DRM DRIVER FOR MSM ADRENO GPU" 
        <linux-arm-msm@vger.kernel.org>,
        "open list:DRM DRIVER FOR MSM ADRENO GPU" 
        <freedreno@lists.freedesktop.org>,
        open list <linux-kernel@vger.kernel.org>
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On Wed, Jul 7, 2021 at 10:57 AM Rob Clark <robdclark@gmail.com> wrote:
>
> From: Rob Clark <robdclark@chromium.org>
>
> It turns out that when the display is enabled by the bootloader, we can
> get some transient iommu faults from the display.  Which doesn't go over
> too well when we install a fault handler that is gpu specific.  To avoid
> this, defer installing the fault handler until we get around to setting
> up per-process pgtables (which is adreno_smmu specific).  The arm-smmu
> fallback error reporting is sufficient for reporting display related
> faults (and in fact was all we had prior to f8f934c180f629bb927a04fd90d)
>
> Reported-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
> Reported-by: Yassine Oudjana <y.oudjana@protonmail.com>
> Fixes: 2a574cc05d38 ("drm/msm: Improve the a6xx page fault handler")
> Signed-off-by: Rob Clark <robdclark@chromium.org>
> Tested-by: John Stultz <john.stultz@linaro.org>
> ---

Hey folks!
  Just wanted to follow up on this, as it's still missing from
5.14-rc3 and is critical for resolving a boot regression on db845c. Is
there anything keeping this from heading upstream?

thanks
-john