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Date:   Tue, 18 Apr 2023 09:54:30 +0200
From:   Marijn Suijten <marijn.suijten@somainline.org>
To:     Abhinav Kumar <quic_abhinavk@quicinc.com>
Cc:     Rob Clark <robdclark@gmail.com>,
        Dmitry Baryshkov <dmitry.baryshkov@linaro.org>,
        Sean Paul <sean@poorly.run>, David Airlie <airlied@gmail.com>,
        Daniel Vetter <daniel@ffwll.ch>,
        ~postmarketos/upstreaming@lists.sr.ht,
        AngeloGioacchino Del Regno 
        <angelogioacchino.delregno@somainline.org>,
        Konrad Dybcio <konrad.dybcio@linaro.org>,
        Martin Botka <martin.botka@somainline.org>,
        Jami Kettunen <jami.kettunen@somainline.org>,
        Jordan Crouse <jordan@cosmicpenguin.net>,
        linux-arm-msm@vger.kernel.org, dri-devel@lists.freedesktop.org,
        freedreno@lists.freedesktop.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/3] drm/msm/dpu: Drop unused members from HW structs
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References: <20230418-dpu-drop-useless-for-lookup-v1-0-b9897ceb6f3e@somainline.org>
 <20230418-dpu-drop-useless-for-lookup-v1-1-b9897ceb6f3e@somainline.org>
 <bb229562-b0af-88f4-1207-ac23a6076dff@quicinc.com>
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On 2023-04-17 18:54:18, Abhinav Kumar wrote:
> 
> On 4/17/2023 4:14 PM, Marijn Suijten wrote:
> > Some of these members were initialized while never read, while others
> > were not even assigned any value at all.  Drop them to save some space,
> > and above all confusion when looking at these members.
> > 
> > Fixes: 25fdd5933e4c ("drm/msm: Add SDM845 DPU support")
> > Fixes: 84a33d0fd921 ("drm/msm/dpu: add dpu_hw_wb abstraction for writeback blocks")
> > Signed-off-by: Marijn Suijten <marijn.suijten@somainline.org>
> > ---
> 
> It seems like WB UBWC formats are not supported today. Because otherwise 
> ctx->mdp would be used for writeback. I guess we can add a ubwc member 
> similar to hw_sspp, when we do add the support for this. Hence this is,

That seems preferable to me.  SSPP does the same in patch 3/3, and I
have been thinking to replace the dpu_mdss_cfg *catalog parameter in
dpu_hw_sspp_init with just the ubwc cfg pointer.  Likewise
dpu_hw_ctl_init also takes the full dpu_mdss_cfg only to take out the
mixers.

- Marijn

> Reviewed-by: Abhinav Kumar <quic_abhinavk@quicinc.com>