[PATCH v2 16/19] drm/msm/dpu: modify encoder programming for CDM over DP

Dmitry Baryshkov dmitry.baryshkov at linaro.org
Tue Feb 13 19:31:00 UTC 2024


On Tue, 13 Feb 2024 at 20:46, Abhinav Kumar <quic_abhinavk at quicinc.com> wrote:
>
>
>
> On 2/13/2024 10:23 AM, Dmitry Baryshkov wrote:
> > On Tue, 13 Feb 2024 at 19:32, Abhinav Kumar <quic_abhinavk at quicinc.com> wrote:
> >>
> >>
> >>
> >> On 2/13/2024 3:18 AM, Dmitry Baryshkov wrote:
> >>> On Sat, 10 Feb 2024 at 03:53, Paloma Arellano <quic_parellan at quicinc.com> wrote:
> >>>>
> >>>> Adjust the encoder format programming in the case of video mode for DP
> >>>> to accommodate CDM related changes.
> >>>>
> >>>> Changes in v2:
> >>>>           - Move timing engine programming to a separate patch from this
> >>>>             one
> >>>>           - Move update_pending_flush_periph() invocation completely to
> >>>>             this patch
> >>>>           - Change the logic of dpu_encoder_get_drm_fmt() so that it only
> >>>>             calls drm_mode_is_420_only() instead of doing additional
> >>>>             unnecessary checks
> >>>>           - Create new functions msm_dp_needs_periph_flush() and it's
> >>>>             supporting function dpu_encoder_needs_periph_flush() to check
> >>>>             if the mode is YUV420 and VSC SDP is enabled before doing a
> >>>>             peripheral flush
> >>>>
> >>>> Signed-off-by: Paloma Arellano <quic_parellan at quicinc.com>
> >>>> ---
> >>>>    drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c   | 35 +++++++++++++++++++
> >>>>    .../gpu/drm/msm/disp/dpu1/dpu_encoder_phys.h  | 13 +++++++
> >>>>    .../drm/msm/disp/dpu1/dpu_encoder_phys_vid.c  | 19 ++++++++++
> >>>>    drivers/gpu/drm/msm/dp/dp_display.c           | 18 ++++++++++
> >>>>    drivers/gpu/drm/msm/msm_drv.h                 | 17 ++++++++-
> >>>>    5 files changed, 101 insertions(+), 1 deletion(-)
> >>>>
> >>>> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
> >>>> index 7e7796561009a..6280c6be6dca9 100644
> >>>> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
> >>>> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
> >>>> @@ -222,6 +222,41 @@ static u32 dither_matrix[DITHER_MATRIX_SZ] = {
> >>>>           15, 7, 13, 5, 3, 11, 1, 9, 12, 4, 14, 6, 0, 8, 2, 10
> >>>>    };
> >>>>
> >>>> +u32 dpu_encoder_get_drm_fmt(struct dpu_encoder_phys *phys_enc)
> >>>> +{
> >>>> +       struct drm_encoder *drm_enc;
> >>>> +       struct dpu_encoder_virt *dpu_enc;
> >>>> +       struct drm_display_info *info;
> >>>> +       struct drm_display_mode *mode;
> >>>> +
> >>>> +       drm_enc = phys_enc->parent;
> >>>> +       dpu_enc = to_dpu_encoder_virt(drm_enc);
> >>>> +       info = &dpu_enc->connector->display_info;
> >>>> +       mode = &phys_enc->cached_mode;
> >>>> +
> >>>> +       if (drm_mode_is_420_only(info, mode))
> >>>> +               return DRM_FORMAT_YUV420;
> >>>> +
> >>>> +       return DRM_FORMAT_RGB888;
> >>>> +}
> >>>> +
> >>>> +bool dpu_encoder_needs_periph_flush(struct dpu_encoder_phys *phys_enc)
> >>>> +{
> >>>> +       struct drm_encoder *drm_enc;
> >>>> +       struct dpu_encoder_virt *dpu_enc;
> >>>> +       struct msm_display_info *disp_info;
> >>>> +       struct msm_drm_private *priv;
> >>>> +       struct drm_display_mode *mode;
> >>>> +
> >>>> +       drm_enc = phys_enc->parent;
> >>>> +       dpu_enc = to_dpu_encoder_virt(drm_enc);
> >>>> +       disp_info = &dpu_enc->disp_info;
> >>>> +       priv = drm_enc->dev->dev_private;
> >>>> +       mode = &phys_enc->cached_mode;
> >>>> +
> >>>> +       return phys_enc->hw_intf->cap->type == INTF_DP && phys_enc->hw_cdm &&
> >>>
> >>> Do we really need to check for phys_enc->hw_cdm here?
> >>>
> >>
> >> hmmm I dont think so. If CDM was not there, then after the last patch,
> >> YUV420 removes will not be present at all.
> >>
> >> The only other case I could think of was, if for some reason CDM was
> >> used by some other interface such as WB, then hw_cdm will not be assigned.
> >>
> >> But, I think even for that msm_dp_needs_periph_flush() will take care of
> >> it because we use the cached_mode which is assigned only in mode_set().
> >>
> >>>> +              msm_dp_needs_periph_flush(priv->dp[disp_info->h_tile_instance[0]], mode);
> >>>> +}
> >>>>
> >>>>    bool dpu_encoder_is_widebus_enabled(const struct drm_encoder *drm_enc)
> >>>>    {
> >>>> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys.h b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys.h
> >>>> index f43d57d9c74e1..211a3d90eb690 100644
> >>>> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys.h
> >>>> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys.h
> >>>> @@ -341,6 +341,19 @@ static inline enum dpu_3d_blend_mode dpu_encoder_helper_get_3d_blend_mode(
> >>>>     */
> >>>>    unsigned int dpu_encoder_helper_get_dsc(struct dpu_encoder_phys *phys_enc);
> >>>>
> >>>> +/**
> >>>> + * dpu_encoder_get_drm_fmt - return DRM fourcc format
> >>>> + * @phys_enc: Pointer to physical encoder structure
> >>>> + */
> >>>> +u32 dpu_encoder_get_drm_fmt(struct dpu_encoder_phys *phys_enc);
> >>>> +
> >>>> +/**
> >>>> + * dpu_encoder_needs_periph_flush - return true if physical encoder requires
> >>>> + *     peripheral flush
> >>>> + * @phys_enc: Pointer to physical encoder structure
> >>>> + */
> >>>> +bool dpu_encoder_needs_periph_flush(struct dpu_encoder_phys *phys_enc);
> >>>> +
> >>>>    /**
> >>>>     * dpu_encoder_helper_split_config - split display configuration helper function
> >>>>     *     This helper function may be used by physical encoders to configure
> >>>> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_vid.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_vid.c
> >>>> index f562beb6f7971..3f102b2813ca8 100644
> >>>> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_vid.c
> >>>> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_vid.c
> >>>> @@ -413,8 +413,15 @@ static int dpu_encoder_phys_vid_control_vblank_irq(
> >>>>    static void dpu_encoder_phys_vid_enable(struct dpu_encoder_phys *phys_enc)
> >>>>    {
> >>>>           struct dpu_hw_ctl *ctl;
> >>>> +       struct dpu_hw_cdm *hw_cdm;
> >>>> +       const struct dpu_format *fmt = NULL;
> >>>> +       u32 fmt_fourcc = DRM_FORMAT_RGB888;
> >>>>
> >>>>           ctl = phys_enc->hw_ctl;
> >>>> +       hw_cdm = phys_enc->hw_cdm;
> >>>> +       if (hw_cdm)
> >>>> +               fmt_fourcc = dpu_encoder_get_drm_fmt(phys_enc);
> >>>
> >>> Please move if(hw_cdm) inside dpu_encoder_get_drm_fmt().
> >>>
> >>
> >> I think we dont need to check for if (hw_cdm) at all.
> >> dpu_encoder_get_drm_fmt() was just supposed to be a helper which returns
> >> the fourcc code based on the mode. It doesnt need to know if there is
> >> cdm or not.
> >>
> >> We cannot move it inside dpu_encoder_helper_phys_setup_cdm() because for
> >> WB, we do not change the fourcc based on the mode. Its specific to video
> >> mode.
> >
> > Wait... In the case of the WB we use the fourcc + modifier from the
> > framebuffer. Ok, this looks fine then.
> >
> >
> >>
> >>>> +       fmt = dpu_get_dpu_format(fmt_fourcc);
> >>>
> >>> Can this be moved into dpu_encoder_helper_phys_setup_cdm() ? Or maybe
> >>> we can move both calls into the helper? I mean, fmt_fourcc is not used
> >>> at all if the CDM is not used.
> >>>
> >>
> >> fourcc is always used to get the fmt to setup the timing engine params.
> >> Its just that it was always hard-coded to RGB. With CDM, it can change
> >> based on the mode. Thats why this utility was introduced to return the
> >> fourcc from the mode information.
> >
> > Yes, I perfectly understand that. I just disliked the idea of calling
> > dpu_get_dpu_format() if the result gets unused.
> > What about passing fourcc + modifier to
> > dpu_encoder_helper_phys_setup_cdm() instead?
> >
>
> Why would it be unused? Its returning YUV420 if the mode is YUV420 and
> RGB otherwise.

I thought about it being unused if there is no CDM in play.

>
> We need fourcc + modifier for video mode timing engine setup. I didnt
> quite follow your suggestion of passing these to
> dpu_encoder_helper_phys_setup_cdm().

Ah, this is modified in the next patch...

Maybe passing fmt_fourcc from this function to setup_timing_engine
will solve my troubles.

>
>
> >>
> >>>>
> >>>>           DPU_DEBUG_VIDENC(phys_enc, "\n");
> >>>>
> >>>> @@ -423,6 +430,8 @@ static void dpu_encoder_phys_vid_enable(struct dpu_encoder_phys *phys_enc)
> >>>>
> >>>>           dpu_encoder_helper_split_config(phys_enc, phys_enc->hw_intf->idx);
> >>>>
> >>>> +       dpu_encoder_helper_phys_setup_cdm(phys_enc, fmt, CDM_CDWN_OUTPUT_HDMI);
> >>>> +
> >>>>           dpu_encoder_phys_vid_setup_timing_engine(phys_enc);
> >>>>
> >>>>           /*
> >>>> @@ -438,6 +447,16 @@ static void dpu_encoder_phys_vid_enable(struct dpu_encoder_phys *phys_enc)
> >>>>           if (ctl->ops.update_pending_flush_merge_3d && phys_enc->hw_pp->merge_3d)
> >>>>                   ctl->ops.update_pending_flush_merge_3d(ctl, phys_enc->hw_pp->merge_3d->idx);
> >>>>
> >>>> +       if (ctl->ops.update_pending_flush_cdm && phys_enc->hw_cdm)
> >>>> +               ctl->ops.update_pending_flush_cdm(ctl, hw_cdm->idx);
> >>>> +
> >>>> +       /*
> >>>> +        * Peripheral flush must be updated whenever flushing SDP packets is needed.
> >>>> +        * SDP packets are required for any YUV format (YUV420, YUV422, YUV444).
> >>>> +        */
> >>>> +       if (ctl->ops.update_pending_flush_periph && dpu_encoder_needs_periph_flush(phys_enc))
> >>>> +               ctl->ops.update_pending_flush_periph(ctl, phys_enc->hw_intf->idx);
> >>>> +
> >>>>    skip_flush:
> >>>>           DPU_DEBUG_VIDENC(phys_enc,
> >>>>                   "update pending flush ctl %d intf %d\n",
> >>>> diff --git a/drivers/gpu/drm/msm/dp/dp_display.c b/drivers/gpu/drm/msm/dp/dp_display.c
> >>>> index 4b04388719363..ebcc76ef1d590 100644
> >>>> --- a/drivers/gpu/drm/msm/dp/dp_display.c
> >>>> +++ b/drivers/gpu/drm/msm/dp/dp_display.c
> >>>> @@ -1397,6 +1397,24 @@ void __exit msm_dp_unregister(void)
> >>>>           platform_driver_unregister(&dp_display_driver);
> >>>>    }
> >>>>
> >>>> +bool msm_dp_is_yuv_420_enabled(const struct msm_dp *dp_display,
> >>>> +                              const struct drm_display_mode *mode)
> >>>> +{
> >>>> +       struct dp_display_private *dp;
> >>>> +       const struct drm_display_info *info;
> >>>> +
> >>>> +       dp = container_of(dp_display, struct dp_display_private, dp_display);
> >>>> +       info = &dp_display->connector->display_info;
> >>>> +
> >>>> +       return dp->panel->vsc_sdp_supported && drm_mode_is_420_only(info, mode);
> >>>> +}
> >>>> +
> >>>> +bool msm_dp_needs_periph_flush(const struct msm_dp *dp_display,
> >>>> +                              const struct drm_display_mode *mode)
> >>>> +{
> >>>> +       return msm_dp_is_yuv_420_enabled(dp_display, mode);
> >>>> +}
> >>>> +
> >>>>    bool msm_dp_wide_bus_available(const struct msm_dp *dp_display)
> >>>>    {
> >>>>           struct dp_display_private *dp;
> >>>> diff --git a/drivers/gpu/drm/msm/msm_drv.h b/drivers/gpu/drm/msm/msm_drv.h
> >>>> index 16a7cbc0b7dd8..b876ebd48effe 100644
> >>>> --- a/drivers/gpu/drm/msm/msm_drv.h
> >>>> +++ b/drivers/gpu/drm/msm/msm_drv.h
> >>>> @@ -387,7 +387,10 @@ void __exit msm_dp_unregister(void);
> >>>>    int msm_dp_modeset_init(struct msm_dp *dp_display, struct drm_device *dev,
> >>>>                            struct drm_encoder *encoder);
> >>>>    void msm_dp_snapshot(struct msm_disp_state *disp_state, struct msm_dp *dp_display);
> >>>> -
> >>>> +bool msm_dp_is_yuv_420_enabled(const struct msm_dp *dp_display,
> >>>> +                              const struct drm_display_mode *mode);
> >>>> +bool msm_dp_needs_periph_flush(const struct msm_dp *dp_display,
> >>>> +                              const struct drm_display_mode *mode);
> >>>>    bool msm_dp_wide_bus_available(const struct msm_dp *dp_display);
> >>>>
> >>>>    #else
> >>>> @@ -409,6 +412,18 @@ static inline void msm_dp_snapshot(struct msm_disp_state *disp_state, struct msm
> >>>>    {
> >>>>    }
> >>>>
> >>>> +static inline bool msm_dp_is_yuv_420_enabled(const struct msm_dp *dp_display,
> >>>> +                                            const struct drm_display_mode *mode)
> >>>> +{
> >>>> +       return false;
> >>>> +}
> >>>> +
> >>>> +static inline bool msm_dp_needs_periph_flush(const struct msm_dp *dp_display,
> >>>> +                                            const struct drm_display_mode *mode)
> >>>> +{
> >>>> +       return false;
> >>>> +}
> >>>> +
> >>>>    static inline bool msm_dp_wide_bus_available(const struct msm_dp *dp_display)
> >>>>    {
> >>>>           return false;
> >>>> --
> >>>> 2.39.2
> >>>>
> >>>
> >>>
> >
> >
> >



-- 
With best wishes
Dmitry


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