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From:   Doug Anderson <dianders@chromium.org>
Date:   Thu, 28 Jul 2022 17:22:18 -0700
Message-ID: <CAD=FV=U_GStziLOCVLs_FC_2Vr=ykGfbb4ZtUp79iV8V=B0cEA@mail.gmail.com>
Subject: Re: [PATCH v6 00/10] Add PSR support for eDP
To:     Vinod Polimera <quic_vpolimer@quicinc.com>
Cc:     dri-devel <dri-devel@lists.freedesktop.org>,
        linux-arm-msm <linux-arm-msm@vger.kernel.org>,
        freedreno <freedreno@lists.freedesktop.org>,
        "open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" 
        <devicetree@vger.kernel.org>, LKML <linux-kernel@vger.kernel.org>,
        Rob Clark <robdclark@gmail.com>,
        Stephen Boyd <swboyd@chromium.org>,
        quic_kalyant <quic_kalyant@quicinc.com>,
        Dmitry Baryshkov <dmitry.baryshkov@linaro.org>,
        "Kuogee Hsieh (QUIC)" <quic_khsieh@quicinc.com>,
        quic_vproddut <quic_vproddut@quicinc.com>,
        Bjorn Andersson <bjorn.andersson@linaro.org>,
        "Aravind Venkateswaran (QUIC)" <quic_aravindh@quicinc.com>,
        "Abhinav Kumar (QUIC)" <quic_abhinavk@quicinc.com>,
        Sankeerth Billakanti <quic_sbillaka@quicinc.com>
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Hi,

On Mon, Jul 11, 2022 at 5:57 AM Vinod Polimera
<quic_vpolimer@quicinc.com> wrote:
>
> Changes in v2:
>   - Use dp bridge to set psr entry/exit instead of dpu_enocder.
>   - Don't modify whitespaces.
>   - Set self refresh aware from atomic_check.
>   - Set self refresh aware only if psr is supported.
>   - Provide a stub for msm_dp_display_set_psr.
>   - Move dp functions to bridge code.
>
> Changes in v3:
>   - Change callback names to reflect atomic interfaces.
>   - Move bridge callback change to separate patch as suggested by Dmitry.
>   - Remove psr function declaration from msm_drv.h.
>   - Set self_refresh_aware flag only if psr is supported.
>   - Modify the variable names to simpler form.
>   - Define bit fields for PSR settings.
>   - Add comments explaining the steps to enter/exit psr.
>   - Change DRM_INFO to drm_dbg_db.
>
> Changes in v4:
>   - Move the get crtc functions to drm_atomic.
>   - Add atomic functions for DP bridge too.
>   - Add ternary operator to choose eDP or DP ops.
>   - Return true/false instead of 1/0.
>   - mode_valid missing in the eDP bridge ops.
>   - Move the functions to get crtc into drm_atomic.c.
>   - Fix compilation issues.
>   - Remove dpu_assign_crtc and get crtc from drm_enc instead of dpu_enc.
>   - Check for crtc state enable while reserving resources.
>
> Changes in v5:
>   - Move the mode_valid changes into a different patch.
>   - Complete psr_op_comp only when isr is set.
>   - Move the DP atomic callback changes to a different patch.
>   - Get crtc from drm connector state crtc.
>   - Move to separate patch for check for crtc state enable while
> reserving resources.
>
> Changes in v6:
>   - Remove crtc from dpu_encoder_virt struct.
>   - fix crtc check during vblank toggle crtc.
>   - Misc changes.
>
> Signed-off-by: Sankeerth Billakanti <quic_sbillaka@quicinc.com>
> Signed-off-by: Kalyan Thota <quic_kalyant@quicinc.com>
> Signed-off-by: Vinod Polimera <quic_vpolimer@quicinc.com>
>
> Vinod Polimera (10):
>   drm/msm/disp/dpu: clear dpu_assign_crtc and get crtc from connector
>     state instead of dpu_enc
>   drm: add helper functions to retrieve old and new crtc
>   drm/msm/dp: use atomic callbacks for DP bridge ops
>   drm/msm/dp: Add basic PSR support for eDP
>   drm/msm/dp: use the eDP bridge ops to validate eDP modes
>   drm/bridge: use atomic enable/disable callbacks for panel bridge
>   drm/bridge: add psr support for panel bridge callbacks
>   drm/msm/disp/dpu: use atomic enable/disable callbacks for encoder
>     functions
>   drm/msm/disp/dpu: add PSR support for eDP interface in dpu driver
>   drm/msm/disp/dpu: check for crtc enable rather than crtc active to
>     release shared resources
>
>  drivers/gpu/drm/bridge/panel.c              |  68 ++++++++--
>  drivers/gpu/drm/drm_atomic.c                |  60 +++++++++
>  drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c    |  17 ++-
>  drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c |  56 +++++----
>  drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.h |   8 --
>  drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c     |   2 +-
>  drivers/gpu/drm/msm/dp/dp_catalog.c         |  81 ++++++++++++
>  drivers/gpu/drm/msm/dp/dp_catalog.h         |   4 +
>  drivers/gpu/drm/msm/dp/dp_ctrl.c            |  73 +++++++++++
>  drivers/gpu/drm/msm/dp/dp_ctrl.h            |   3 +
>  drivers/gpu/drm/msm/dp/dp_display.c         |  31 +++--
>  drivers/gpu/drm/msm/dp/dp_display.h         |   2 +
>  drivers/gpu/drm/msm/dp/dp_drm.c             | 184 ++++++++++++++++++++++++++--
>  drivers/gpu/drm/msm/dp/dp_drm.h             |   9 +-
>  drivers/gpu/drm/msm/dp/dp_link.c            |  36 ++++++
>  drivers/gpu/drm/msm/dp/dp_panel.c           |  22 ++++
>  drivers/gpu/drm/msm/dp/dp_panel.h           |   6 +
>  drivers/gpu/drm/msm/dp/dp_reg.h             |  27 ++++
>  include/drm/drm_atomic.h                    |   7 ++
>  19 files changed, 631 insertions(+), 65 deletions(-)

I spent some time looking at the first few patches. I can try to look
at more later this week, though (as you've noticed) many of my reviews
are more nit-picks because I don't really have experience with PSR and
my overall knowledge of the Qualcomm DP driver is pretty weak.

I tried to at least pick to give a Tested-by, but when I did that it
didn't work flawlessly. I picked this series to the chromeos-5.15
tree, which is pretty close to mainline right now. I left it sitting
at a screen with a blinking cursor which pretty much means it's always
transitioning into and out of PSR. I've seen several glitches on the
screen with the series applied. :( No idea what's wrong--that's just
me black-box testing. I did try to add debug printouts to see if we
were hitting "PSR_UPDATE_ERROR_INT | PSR_WAKE_ERROR_INT" but I didn't
see my printouts...

FWIW: I'm running with KASAN enabled which could affect timings...
Glitches happen every few minutes or so for me and so far I haven't
see any glitches without KASAN, but that could just be chance...

-Doug