[PATCH 14/17] drm/msm/dpu: modify encoder programming for CDM over DP
Dmitry Baryshkov
dmitry.baryshkov at linaro.org
Thu Feb 1 03:17:47 UTC 2024
On Thu, 1 Feb 2024 at 03:30, Abhinav Kumar <quic_abhinavk at quicinc.com> wrote:
>
>
>
> On 1/29/2024 3:44 PM, Dmitry Baryshkov wrote:
> > On Mon, 29 Jan 2024 at 09:08, Abhinav Kumar <quic_abhinavk at quicinc.com> wrote:
> >>
> >> On 1/28/2024 10:12 PM, Dmitry Baryshkov wrote:
> >>> 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)?
> >>>
> >>
> >> Not really leaking any details. Interface decides when DPU's flush bit
> >> needs to be invoked. All the conditions needing the flush can be
> >> absorbed within msm_dp_needs_periph_flush() which will be within DP
> >> driver. So I dont see any issue with that.
> >
> > As long as we have two distinct functions: msm_dp_needs_periph_flush()
> > and msm_dp_is_yuv420_enabled(), it's fine with me.
> >
>
> I am okay with it being distinct but in this series and till DP DSC is
> posted, we have only YUV420 SDP use-case for peripheral flush.
>
> So are you okay with the fact that the code will look something like
>
> bool msm_dp_needs_periph_flush() {
> return msm_dp_is_yuv420_enabled();
> }
Yes. The reason is that if at some point conditions for periph flush
get changed, you won't have to change the API between DPU and DP
drivers.
>
> >>
> >> The peripheral flush needs to be invoked whenever SDP/PPS packets need
> >> to be sent out at the very least. Those are the two main use-cases so far.
> >>
> >> Not necessarily each time the INTF is enabled.
> >>
> >> But ....
> >>
> >> For PPS, we would typically enable DSC from the first frame itself and
> >> we dont support dynamically turning DSC ON/OFF so its a fair assumption
> >> that we need to the peripheral flush for DSC only during enable.
> >>
> >> For SDP, so today we enforce a modeset when we switch from a case of
> >> needing cdm / not needing cdm and vice-versa. So even this use-case
> >> should be accompanied by a disable()/enable().
> >
> > My point was that there might be other changes to the SDP infoframe.
> >
> >>
> >> So are you suggesting that we unconditionally just do peripheral_flush
> >> from enable()?
> >>
> >> I need to do some checking but maybe ....
> >
> > This might be an option too. I don't know what delays / issues it can cause.
> >
>
> I will check this if the other option we discussed above does not work
> for you.
>
> >>
> >>>>
> >>>> 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.
> >>>
> >>
> >> Ugh no. Not another rework just for this.
> >
> > It is pending for the CTL flush story.
> >
> >>
> >>>>
> >>>> 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).
--
With best wishes
Dmitry
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