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References: <20210330013408.2532048-1-john.stultz@linaro.org>
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From:   Doug Anderson <dianders@chromium.org>
Date:   Tue, 30 Mar 2021 08:14:51 -0700
Message-ID: <CAD=FV=XbwNmmeoZOSso3Kz1mP40ONo0hDvn6KP8zZsdg9uPcNg@mail.gmail.com>
Subject: Re: [PATCH] drm/msm: Fix removal of valid error case when checking speed_bin
To:     John Stultz <john.stultz@linaro.org>
Cc:     lkml <linux-kernel@vger.kernel.org>,
        Rob Clark <robdclark@gmail.com>, Sean Paul <sean@poorly.run>,
        Jordan Crouse <jcrouse@codeaurora.org>,
        Eric Anholt <eric@anholt.net>,
        linux-arm-msm <linux-arm-msm@vger.kernel.org>,
        freedreno <freedreno@lists.freedesktop.org>,
        Bjorn Andersson <bjorn.andersson@linaro.org>,
        YongQin Liu <yongqin.liu@linaro.org>
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Precedence: bulk

Hi,

On Mon, Mar 29, 2021 at 6:34 PM John Stultz <john.stultz@linaro.org> wrote:
>
> Commit 7bf168c8fe8c  ("drm/msm: Fix speed-bin support not to
> access outside valid memory"), reworked the nvmem reading of
> "speed_bin", but in doing so dropped handling of the -ENOENT
> case which was previously documented as "fine".
>
> That change resulted in the db845c board display to fail to
> start, with the following error:
>
> adreno 5000000.gpu: [drm:a6xx_gpu_init] *ERROR* failed to read speed-bin (-2). Some OPPs may not be supported by hardware
>
> Thus, this patch simply re-adds the ENOENT handling so the lack
> of the speed_bin entry isn't fatal for display, and gets things
> working on db845c.
>
> Cc: Rob Clark <robdclark@gmail.com>
> Cc: Sean Paul <sean@poorly.run>
> Cc: Jordan Crouse <jcrouse@codeaurora.org>
> Cc: Eric Anholt <eric@anholt.net>
> Cc: Douglas Anderson <dianders@chromium.org>
> Cc: linux-arm-msm@vger.kernel.org
> Cc: freedreno@lists.freedesktop.org
> Cc: Bjorn Andersson <bjorn.andersson@linaro.org>
> Cc: YongQin Liu <yongqin.liu@linaro.org>
> Reported-by: YongQin Liu <yongqin.liu@linaro.org>
> Fixes: 7bf168c8fe8c  ("drm/msm: Fix speed-bin support not to access outside valid memory")
> Signed-off-by: John Stultz <john.stultz@linaro.org>
> ---
>  drivers/gpu/drm/msm/adreno/a6xx_gpu.c | 8 +++++++-
>  1 file changed, 7 insertions(+), 1 deletion(-)

Reviewed-by: Douglas Anderson <dianders@chromium.org>