[PATCH 14/17] drm/msm/dpu: modify encoder programming for CDM over DP

Dmitry Baryshkov dmitry.baryshkov at linaro.org
Mon Jan 29 06:12:44 UTC 2024


On Mon, 29 Jan 2024 at 07:03, Abhinav Kumar <quic_abhinavk at quicinc.com> wrote:
>
>
>
> On 1/28/2024 7:42 PM, Dmitry Baryshkov wrote:
> > On Mon, 29 Jan 2024 at 04:58, Abhinav Kumar <quic_abhinavk at quicinc.com> wrote:
> >>
> >>
> >>
> >> On 1/27/2024 9:55 PM, Dmitry Baryshkov wrote:
> >>> On Sun, 28 Jan 2024 at 07:48, Paloma Arellano <quic_parellan at quicinc.com> wrote:
> >>>>
> >>>>
> >>>> On 1/25/2024 1:57 PM, Dmitry Baryshkov wrote:
> >>>>> On 25/01/2024 21:38, Paloma Arellano wrote:
> >>>>>> Adjust the encoder format programming in the case of video mode for DP
> >>>>>> to accommodate CDM related changes.
> >>>>>>
> >>>>>> Signed-off-by: Paloma Arellano <quic_parellan at quicinc.com>
> >>>>>> ---
> >>>>>>     drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c   | 16 +++++++++
> >>>>>>     drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.h   |  8 +++++
> >>>>>>     .../drm/msm/disp/dpu1/dpu_encoder_phys_vid.c  | 35 ++++++++++++++++---
> >>>>>>     drivers/gpu/drm/msm/dp/dp_display.c           | 12 +++++++
> >>>>>>     drivers/gpu/drm/msm/msm_drv.h                 |  9 ++++-
> >>>>>>     5 files changed, 75 insertions(+), 5 deletions(-)
> >>>>>>
> >>>>>> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
> >>>>>> b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
> >>>>>> index b0896814c1562..99ec53446ad21 100644
> >>>>>> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
> >>>>>> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
> >>>>>> @@ -222,6 +222,22 @@ 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(const struct drm_encoder *drm_enc,
> >>>>>> const struct drm_display_mode *mode)
> >>>>>> +{
> >>>>>> +    const struct dpu_encoder_virt *dpu_enc;
> >>>>>> +    const struct msm_display_info *disp_info;
> >>>>>> +    struct msm_drm_private *priv;
> >>>>>> +
> >>>>>> +    dpu_enc = to_dpu_encoder_virt(drm_enc);
> >>>>>> +    disp_info = &dpu_enc->disp_info;
> >>>>>> +    priv = drm_enc->dev->dev_private;
> >>>>>> +
> >>>>>> +    if (disp_info->intf_type == INTF_DP &&
> >>>>>> + msm_dp_is_yuv_420_enabled(priv->dp[disp_info->h_tile_instance[0]],
> >>>>>> mode))
> >>>>>
> >>>>> This should not require interacting with DP. If we got here, we must
> >>>>> be sure that 4:2:0 is supported and can be configured.
> >>>> Ack. Will drop this function and only check for if the mode is YUV420.
> >>>>>
> >>>>>> +        return DRM_FORMAT_YUV420;
> >>>>>> +
> >>>>>> +    return DRM_FORMAT_RGB888;
> >>>>>> +}
> >>>>>>       bool dpu_encoder_is_widebus_enabled(const struct drm_encoder
> >>>>>> *drm_enc)
> >>>>>>     {
> >>>>>> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.h
> >>>>>> b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.h
> >>>>>> index 7b4afa71f1f96..62255d0aa4487 100644
> >>>>>> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.h
> >>>>>> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.h
> >>>>>> @@ -162,6 +162,14 @@ int dpu_encoder_get_vsync_count(struct
> >>>>>> drm_encoder *drm_enc);
> >>>>>>      */
> >>>>>>     bool dpu_encoder_is_widebus_enabled(const struct drm_encoder
> >>>>>> *drm_enc);
> >>>>>>     +/**
> >>>>>> + * dpu_encoder_get_drm_fmt - return DRM fourcc format
> >>>>>> + * @drm_enc:    Pointer to previously created drm encoder structure
> >>>>>> + * @mode:    Corresponding drm_display_mode for dpu encoder
> >>>>>> + */
> >>>>>> +u32 dpu_encoder_get_drm_fmt(const struct drm_encoder *drm_enc,
> >>>>>> +                const struct drm_display_mode *mode);
> >>>>>> +
> >>>>>>     /**
> >>>>>>      * dpu_encoder_get_crc_values_cnt - get number of physical encoders
> >>>>>> contained
> >>>>>>      *    in virtual encoder that can collect CRC values
> >>>>>> 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 e284bf448bdda..a1dde0ff35dc8 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
> >>>>>> @@ -234,6 +234,7 @@ static void
> >>>>>> dpu_encoder_phys_vid_setup_timing_engine(
> >>>>>>     {
> >>>>>>         struct drm_display_mode mode;
> >>>>>>         struct dpu_hw_intf_timing_params timing_params = { 0 };
> >>>>>> +    struct dpu_hw_cdm *hw_cdm;
> >>>>>>         const struct dpu_format *fmt = NULL;
> >>>>>>         u32 fmt_fourcc = DRM_FORMAT_RGB888;
> >>>>>>         unsigned long lock_flags;
> >>>>>> @@ -254,17 +255,26 @@ static void
> >>>>>> dpu_encoder_phys_vid_setup_timing_engine(
> >>>>>>         DPU_DEBUG_VIDENC(phys_enc, "enabling mode:\n");
> >>>>>>         drm_mode_debug_printmodeline(&mode);
> >>>>>>     -    if (phys_enc->split_role != ENC_ROLE_SOLO) {
> >>>>>> +    hw_cdm = phys_enc->hw_cdm;
> >>>>>> +    if (hw_cdm) {
> >>>>>> +        intf_cfg.cdm = hw_cdm->idx;
> >>>>>> +        fmt_fourcc = dpu_encoder_get_drm_fmt(phys_enc->parent, &mode);
> >>>>>> +    }
> >>>>>> +
> >>>>>> +    if (phys_enc->split_role != ENC_ROLE_SOLO ||
> >>>>>> +        dpu_encoder_get_drm_fmt(phys_enc->parent, &mode) ==
> >>>>>> DRM_FORMAT_YUV420) {
> >>>>>>             mode.hdisplay >>= 1;
> >>>>>>             mode.htotal >>= 1;
> >>>>>>             mode.hsync_start >>= 1;
> >>>>>>             mode.hsync_end >>= 1;
> >>>>>> +        mode.hskew >>= 1;
> >>>>>
> >>>>> Separate patch.
> >>>> Ack.
> >>>>>
> >>>>>>               DPU_DEBUG_VIDENC(phys_enc,
> >>>>>> -            "split_role %d, halve horizontal %d %d %d %d\n",
> >>>>>> +            "split_role %d, halve horizontal %d %d %d %d %d\n",
> >>>>>>                 phys_enc->split_role,
> >>>>>>                 mode.hdisplay, mode.htotal,
> >>>>>> -            mode.hsync_start, mode.hsync_end);
> >>>>>> +            mode.hsync_start, mode.hsync_end,
> >>>>>> +            mode.hskew);
> >>>>>>         }
> >>>>>>           drm_mode_to_intf_timing_params(phys_enc, &mode, &timing_params);
> >>>>>> @@ -412,8 +422,15 @@ 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->parent,
> >>>>>> &phys_enc->cached_mode);
> >>>>>> +    fmt = dpu_get_dpu_format(fmt_fourcc);
> >>>>>>           DPU_DEBUG_VIDENC(phys_enc, "\n");
> >>>>>>     @@ -422,6 +439,8 @@ 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);
> >>>>>
> >>>>> If there is no CDM, why do we need to call this?
> >>>> Inside of dpu_encoder_helper_phys_setup_cdm(), there's a check to see if
> >>>> there is a hw_cdm. If there is not, then it immediately exits the function.
> >>>>>
> >>>>>> +
> >>>>>>         dpu_encoder_phys_vid_setup_timing_engine(phys_enc);
> >>>>>>           /*
> >>>>>> @@ -437,7 +456,15 @@ 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_periph &&
> >>>>>> phys_enc->hw_intf->cap->type == INTF_DP)
> >>>>>> +    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 &&
> >>>>>> phys_enc->hw_intf->cap->type == INTF_DP &&
> >>>>>> +        phys_enc->hw_cdm)
> >>>>>>             ctl->ops.update_pending_flush_periph(ctl,
> >>>>>> phys_enc->hw_intf->idx);
> >>>>>
> >>>>> Should there be a flush if we are switching from YUV 420 to RGB mode?
> >>>> We only need to flush for the sdp packet, but for msa we do not need to
> >>>> flush.
> >>>
> >>> What about having SDP with RGB as colorimetry? In other words, if
> >>> there is a decision point, this one looks incorrect.
> >>>
> >>
> >> There are two ways to do it:
> >>
> >> 1) Use SDP for both RGB and YUV as that supports both. If we implement
> >> this policy, then what you are asking for is correct that we will need
> >> SDP even to switch back to RGB. But to implement this we will also need
> >> to have some sort of state management in the encoder layer about what is
> >> the current encoder fmt Vs what is the prev fmt and then trigger
> >> peripheral flush only during transitions from RGB to YUV and vice-versa
> >>
> >> 2) Use SDP only for YUV because MSA does not support YUV formats and use
> >> MSA for RGB
> >>
> >> We decided to implement (2) and there is no significant impact of
> >> switching between MSA and SDPs but state management becomes easier.
> >
> > Yes. However as you wrote, there might be other usecases concerning
> > SDP. Having this in mind, it sounds like the driver should decide
> > whether to flush peripheral at a different place (when the SDP
> > infoframe is being updated?). And the dpu_encoder_phys_vid_enable()
> > should use this previous decision. Maybe this should be a part of
> > msm_dp_ API, something like msm_dp_needs_peripheral_flush()?
> >
>
> Correct. The decision to flush peripheral or not certainly comes from
> the peripheral itself . In this case its DP.
>
> I think perhaps the usage of hw_cdm here makes it hard to understand
> that but the idea behind this was that in the change "drm/msm/dpu:
> reserve CDM blocks for DP if mode is YUV420 ", hw_cdm is assigned only
> if msm_dp_is_yuv_420_enabled() returns true.

Yes.

>
> So in some sense, the API you are asking for is already
> msm_dp_is_yuv_420_enabled() but we can rename that to
> msm_dp_needs_periph_flush().

No. This leaks details. We might need peripheral flush for other
reasons. So this decision should be made inside the DP driver.
BTW, is there a need to flush-peripheral each time the INTF gets
enabled? When some bits of configuration were updated (like SDP
infoframe or CDM config)?

>
> The issue here is the phys layer cannot call msm_dp_is_yuv_420_enabled()
> so its kind of round-about by checking hw_cdm.

Which maybe means that I should finish phys / encoder rework.

>
> The check is not entirely wrong because for DP, we need hw_cdm for all
> YUV formats and not just 420 but the relationship is maybe not clear but
> I thought the comment above that would help a bit:
>
> /*
>          * Peripheral flush must be updated whenever flushing SDP packets is
> needed.
>          * SDP packets are required for any YUV format (YUV420, YUV422, YUV444).
>          */
>
> The only other way I can think of is maybe we need to introduce a new
> phys variable called phys_enc->needs_update_periph_flush and we can set
> that in dpu_encoder.c as that can call msm_dp_needs_periph_flush().
>
> What do you think of this way?

Let me understand first the requirements for peripheral flush (see the
questions above).

>
> >>
> >>>>>
> >>>>> Also, I'd say, we should move update_pending_flush_periph invocation
> >>>>> to this patch.
> >>>> Ack
> >>>>>
> >>>>>>       skip_flush:
> >>>>>> diff --git a/drivers/gpu/drm/msm/dp/dp_display.c
> >>>>>> b/drivers/gpu/drm/msm/dp/dp_display.c
> >>>>>> index 6d764f5b08727..4329435518351 100644
> >>>>>> --- a/drivers/gpu/drm/msm/dp/dp_display.c
> >>>>>> +++ b/drivers/gpu/drm/msm/dp/dp_display.c
> >>>>>> @@ -1399,6 +1399,18 @@ 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(dp->panel) &&
> >>>>>> drm_mode_is_420_only(info, mode);
> >>>>>
> >>>>> YUV 420 modes should be filtered out in mode_valid if VSC SDP is not
> >>>>> supported.
> >>>> Ack. Will change
> >>>>>
> >>>>>> +}
> >>>>>> +
> >>>>>>     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..b9581bd934e9e 100644
> >>>>>> --- a/drivers/gpu/drm/msm/msm_drv.h
> >>>>>> +++ b/drivers/gpu/drm/msm/msm_drv.h
> >>>>>> @@ -387,7 +387,8 @@ 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_wide_bus_available(const struct msm_dp *dp_display);
> >>>>>>       #else
> >>>>>> @@ -409,6 +410,12 @@ 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_wide_bus_available(const struct msm_dp
> >>>>>> *dp_display)
> >>>>>>     {
> >>>>>>         return false;
> >>>>>
> >>>
> >>>
> >>>
> >>> --
> >>> With best wishes
> >>> Dmitry
> >
> >
> >



-- 
With best wishes
Dmitry


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