[Freedreno] [PATCH v9 01/15] drm/msm/disp/dpu: clear dpu_assign_crtc and get crtc from connector state instead of dpu_enc

Vinod Polimera vpolimer at qti.qualcomm.com
Wed Dec 21 14:10:05 UTC 2022



> -----Original Message-----
> From: Dmitry Baryshkov <dmitry.baryshkov at linaro.org>
> Sent: Wednesday, December 14, 2022 9:05 PM
> To: Vinod Polimera (QUIC) <quic_vpolimer at quicinc.com>; dri-
> devel at lists.freedesktop.org; linux-arm-msm at vger.kernel.org;
> freedreno at lists.freedesktop.org; devicetree at vger.kernel.org
> Cc: linux-kernel at vger.kernel.org; robdclark at gmail.com;
> dianders at chromium.org; swboyd at chromium.org; Kalyan Thota (QUIC)
> <quic_kalyant at quicinc.com>; Kuogee Hsieh (QUIC)
> <quic_khsieh at quicinc.com>; Vishnuvardhan Prodduturi (QUIC)
> <quic_vproddut at quicinc.com>; Bjorn Andersson (QUIC)
> <quic_bjorande at quicinc.com>; Aravind Venkateswaran (QUIC)
> <quic_aravindh at quicinc.com>; Abhinav Kumar (QUIC)
> <quic_abhinavk at quicinc.com>; Sankeerth Billakanti (QUIC)
> <quic_sbillaka at quicinc.com>
> Subject: Re: [PATCH v9 01/15] drm/msm/disp/dpu: clear dpu_assign_crtc and
> get crtc from connector state instead of dpu_enc
> 
> WARNING: This email originated from outside of Qualcomm. Please be wary
> of any links or attachments, and do not enable macros.
> 
> On 14/12/2022 12:05, Vinod Polimera wrote:
> > Update crtc retrieval from dpu_enc to dpu_enc connector state,
> > since new links get set as part of the dpu enc virt mode set.
> > The dpu_enc->crtc cache is no more needed, hence cleaning it as
> > part of this change.
> >
> > This patch is dependent on the series:
> > https://patchwork.freedesktop.org/series/110969/
> >
> > Signed-off-by: Vinod Polimera <quic_vpolimer at quicinc.com>
> > ---
> >   drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c    |  4 ---
> >   drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c | 42 +++++++++---------
> -----------
> >   drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.h |  8 ------
> >   3 files changed, 13 insertions(+), 41 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c
> b/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c
> > index 3f72d38..289d51e 100644
> > --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c
> > +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c
> > @@ -1029,7 +1029,6 @@ static void dpu_crtc_disable(struct drm_crtc *crtc,
> >                */
> >               if (dpu_encoder_get_intf_mode(encoder) == INTF_MODE_VIDEO)
> >                       release_bandwidth = true;
> > -             dpu_encoder_assign_crtc(encoder, NULL);
> >       }
> >
> >       /* wait for frame_event_done completion */
> > @@ -1099,9 +1098,6 @@ static void dpu_crtc_enable(struct drm_crtc *crtc,
> >       trace_dpu_crtc_enable(DRMID(crtc), true, dpu_crtc);
> >       dpu_crtc->enabled = true;
> >
> > -     drm_for_each_encoder_mask(encoder, crtc->dev, crtc->state-
> >encoder_mask)
> > -             dpu_encoder_assign_crtc(encoder, crtc);
> > -
> >       /* Enable/restore vblank irq handling */
> >       drm_crtc_vblank_on(crtc);
> >   }
> > diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
> b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
> > index a585036..b9b254d 100644
> > --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
> > +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
> > @@ -132,11 +132,6 @@ enum dpu_enc_rc_states {
> >    * @intfs_swapped:  Whether or not the phys_enc interfaces have been
> swapped
> >    *                  for partial update right-only cases, such as pingpong
> >    *                  split where virtual pingpong does not generate IRQs
> > - * @crtc:            Pointer to the currently assigned crtc. Normally you
> > - *                   would use crtc->state->encoder_mask to determine the
> > - *                   link between encoder/crtc. However in this case we need
> > - *                   to track crtc in the disable() hook which is called
> > - *                   _after_ encoder_mask is cleared.
> >    * @connector:              If a mode is set, cached pointer to the active
> connector
> >    * @crtc_kickoff_cb:                Callback into CRTC that will flush & start
> >    *                          all CTL paths
> > @@ -181,7 +176,6 @@ struct dpu_encoder_virt {
> >
> >       bool intfs_swapped;
> >
> > -     struct drm_crtc *crtc;
> >       struct drm_connector *connector;
> >
> >       struct dentry *debugfs_root;
> > @@ -1317,7 +1311,7 @@ static void dpu_encoder_vblank_callback(struct
> drm_encoder *drm_enc,
> >               struct dpu_encoder_phys *phy_enc)
> >   {
> >       struct dpu_encoder_virt *dpu_enc = NULL;
> > -     unsigned long lock_flags;
> > +     struct drm_crtc *crtc;
> >
> >       if (!drm_enc || !phy_enc)
> >               return;
> > @@ -1325,12 +1319,13 @@ static void dpu_encoder_vblank_callback(struct
> drm_encoder *drm_enc,
> >       DPU_ATRACE_BEGIN("encoder_vblank_callback");
> >       dpu_enc = to_dpu_encoder_virt(drm_enc);
> >
> > -     atomic_inc(&phy_enc->vsync_cnt);
> > +     if (!dpu_enc->connector || !dpu_enc->connector->state ||
> > +         !dpu_enc->connector->state->crtc)
> > +             return;
> >
> > -     spin_lock_irqsave(&dpu_enc->enc_spinlock, lock_flags);
> > -     if (dpu_enc->crtc)
> > -             dpu_crtc_vblank_callback(dpu_enc->crtc);
> > -     spin_unlock_irqrestore(&dpu_enc->enc_spinlock, lock_flags);
> > +     atomic_inc(&phy_enc->vsync_cnt);
> > +     crtc = dpu_enc->connector->state->crtc;
> > +     dpu_crtc_vblank_callback(crtc);
> >
> >       DPU_ATRACE_END("encoder_vblank_callback");
> >   }
> > @@ -1353,33 +1348,22 @@ static void
> dpu_encoder_underrun_callback(struct drm_encoder *drm_enc,
> >       DPU_ATRACE_END("encoder_underrun_callback");
> >   }
> >
> > -void dpu_encoder_assign_crtc(struct drm_encoder *drm_enc, struct
> drm_crtc *crtc)
> > -{
> > -     struct dpu_encoder_virt *dpu_enc = to_dpu_encoder_virt(drm_enc);
> > -     unsigned long lock_flags;
> > -
> > -     spin_lock_irqsave(&dpu_enc->enc_spinlock, lock_flags);
> > -     /* crtc should always be cleared before re-assigning */
> > -     WARN_ON(crtc && dpu_enc->crtc);
> > -     dpu_enc->crtc = crtc;
> > -     spin_unlock_irqrestore(&dpu_enc->enc_spinlock, lock_flags);
> > -}
> > -
> >   void dpu_encoder_toggle_vblank_for_crtc(struct drm_encoder
> *drm_enc,
> >                                       struct drm_crtc *crtc, bool enable)
> >   {
> >       struct dpu_encoder_virt *dpu_enc = to_dpu_encoder_virt(drm_enc);
> > -     unsigned long lock_flags;
> > +     struct drm_crtc *new_crtc;
> >       int i;
> >
> >       trace_dpu_enc_vblank_cb(DRMID(drm_enc), enable);
> >
> > -     spin_lock_irqsave(&dpu_enc->enc_spinlock, lock_flags);
> > -     if (dpu_enc->crtc != crtc) {
> > -             spin_unlock_irqrestore(&dpu_enc->enc_spinlock, lock_flags);
> > +     if (!dpu_enc->connector || !dpu_enc->connector->state)
> > +             return;
> > +
> > +     new_crtc = dpu_enc->connector->state->crtc;
> > +     if (!new_crtc || new_crtc != crtc) {
> 
> I don't like going through all the pointers and states without locks.
> The connector->state can potentially check. So, I'd propose even simpler
> solution: just store the crtc in the dpu_enc at the creation time. Then
> you can use the rest of the current dpu_enc->crtc as expected.

Can i do as below.
After encoder to crtc is pinned, i can update dpu_encoder structure that is attached with drm_enc with the crtc created during drm_obj_init

@@ -816,6 +816,7 @@ static int _dpu_kms_drm_obj_init(struct dpu_kms *dpu_kms)
                }
                priv->crtcs[priv->num_crtcs++] = crtc;
                encoder->possible_crtcs = 1 << drm_crtc_index(crtc);
              + dpu_encoder_assign_crtc(encoder, crtc);
                i++;
        }

Thanks,
Vinod P.
> 
> >               return;
> >       }
> > -     spin_unlock_irqrestore(&dpu_enc->enc_spinlock, lock_flags);
> >
> >       for (i = 0; i < dpu_enc->num_phys_encs; i++) {
> >               struct dpu_encoder_phys *phys = dpu_enc->phys_encs[i];
> > diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.h
> b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.h
> > index 7f3d823..eb9fc7c 100644
> > --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.h
> > +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.h
> > @@ -40,14 +40,6 @@ struct msm_display_info {
> >   };
> >
> >   /**
> > - * dpu_encoder_assign_crtc - Link the encoder to the crtc it's assigned to
> > - * @encoder: encoder pointer
> > - * @crtc:    crtc pointer
> > - */
> > -void dpu_encoder_assign_crtc(struct drm_encoder *encoder,
> > -                          struct drm_crtc *crtc);
> > -
> > -/**
> >    * dpu_encoder_toggle_vblank_for_crtc - Toggles vblank interrupts on or
> off if
> >    *  the encoder is assigned to the given crtc
> >    * @encoder:        encoder pointer
> 
> --
> With best wishes
> Dmitry



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