Re: [Freedreno] [PATCH 10/12] drm/msm/dpu: initialize dpu encoder and connector for writeback

[Abhinav Kumar <quic_abhinavk@xxxxxxxxxxx>]

On 2/4/2022 2:34 PM, Dmitry Baryshkov wrote:
> On 05/02/2022 00:17, Abhinav Kumar wrote:
> > Initialize dpu encoder and connector for writeback if the
> > target supports it in the catalog.
> >
> > Signed-off-by: Abhinav Kumar <quic_abhinavk@xxxxxxxxxxx>
> > ---
> >   drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c | 37 ++++++++++++-----
> >   drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c     | 62 
> > +++++++++++++++++++++++++++++
> >   2 files changed, 88 insertions(+), 11 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c 
> > b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
> > index b51a677..3746432 100644
> > --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
> > +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
> > @@ -2066,7 +2066,7 @@ static void dpu_encoder_early_unregister(struct 
> > drm_encoder *encoder)
> >   }
> >   static int dpu_encoder_virt_add_phys_encs(
> > -        u32 display_caps,
> > +        struct msm_display_info *disp_info,
> >           struct dpu_encoder_virt *dpu_enc,
> >           struct dpu_enc_phys_init_params *params)
> >   {
> > @@ -2085,7 +2085,7 @@ static int dpu_encoder_virt_add_phys_encs(
> >           return -EINVAL;
> >       }
> > -    if (display_caps & MSM_DISPLAY_CAP_VID_MODE) {
> > +    if (disp_info->capabilities & MSM_DISPLAY_CAP_VID_MODE) {
> >           enc = dpu_encoder_phys_vid_init(params);
> >           if (IS_ERR_OR_NULL(enc)) {
> > @@ -2098,7 +2098,7 @@ static int dpu_encoder_virt_add_phys_encs(
> >           ++dpu_enc->num_phys_encs;
> >       }
> > -    if (display_caps & MSM_DISPLAY_CAP_CMD_MODE) {
> > +    if (disp_info->capabilities & MSM_DISPLAY_CAP_CMD_MODE) {
> >           enc = dpu_encoder_phys_cmd_init(params);
> >           if (IS_ERR_OR_NULL(enc)) {
> > @@ -2111,6 +2111,19 @@ static int dpu_encoder_virt_add_phys_encs(
> >           ++dpu_enc->num_phys_encs;
> >       }
> > +    if (disp_info->intf_type == DRM_MODE_ENCODER_VIRTUAL) {
> > +        enc = dpu_encoder_phys_wb_init(params);
> > +
> > +        if (IS_ERR_OR_NULL(enc)) {
> > +            DPU_ERROR_ENC(dpu_enc, "failed to init wb enc: %ld\n",
> > +                    PTR_ERR(enc));
> > +            return enc == NULL ? -EINVAL : PTR_ERR(enc);
> > +        }
> > +
> > +        dpu_enc->phys_encs[dpu_enc->num_phys_encs] = enc;
> > +        ++dpu_enc->num_phys_encs;
> > +    }
> > +
> >       if (params->split_role == ENC_ROLE_SLAVE)
> >           dpu_enc->cur_slave = enc;
> >       else
> > @@ -2199,9 +2212,8 @@ static int dpu_encoder_setup_display(struct 
> > dpu_encoder_virt *dpu_enc,
> >           }
> >           if (!ret) {
> > -            ret = 
> > dpu_encoder_virt_add_phys_encs(disp_info->capabilities,
> > -                                                 dpu_enc,
> > -                                                 &phys_params);
> > +            ret = dpu_encoder_virt_add_phys_encs(disp_info,
> > +                    dpu_enc, &phys_params);
> >               if (ret)
> >                   DPU_ERROR_ENC(dpu_enc, "failed to add phys encs\n");
> >           }
> > @@ -2317,11 +2329,14 @@ struct drm_encoder *dpu_encoder_init(struct 
> > drm_device *dev,
> >       if (!dpu_enc)
> >           return ERR_PTR(-ENOMEM);
> > -    rc = drm_encoder_init(dev, &dpu_enc->base, &dpu_encoder_funcs,
> > -            drm_enc_mode, NULL);
> > -    if (rc) {
> > -        devm_kfree(dev->dev, dpu_enc);
> > -        return ERR_PTR(rc);
> > +    /* this is handled by drm_writeback_connector_init for virtual 
> > encoder */
> > +    if (drm_enc_mode != DRM_MODE_ENCODER_VIRTUAL) {
> > +        rc = drm_encoder_init(dev, &dpu_enc->base, &dpu_encoder_funcs,
> > +                              drm_enc_mode, NULL);
> > +        if (rc) {
> > +            devm_kfree(dev->dev, dpu_enc);
> > +            return ERR_PTR(rc);
> > +        }
> >       }
> >       drm_encoder_helper_add(&dpu_enc->base, &dpu_encoder_helper_funcs);
> > diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c 
> > b/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c
> > index 47fe11a..6327ba9 100644
> > --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c
> > +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c
> > @@ -1,5 +1,6 @@
> >   // SPDX-License-Identifier: GPL-2.0-only
> >   /*
> > + * Copyright (c) 2022 Qualcomm Innovation Center, Inc. All rights 
> > reserved.
> >    * Copyright (c) 2014-2018, The Linux Foundation. All rights reserved.
> >    * Copyright (C) 2013 Red Hat
> >    * Author: Rob Clark <robdclark@xxxxxxxxx>
> > @@ -15,6 +16,7 @@
> >   #include <drm/drm_crtc.h>
> >   #include <drm/drm_file.h>
> >   #include <drm/drm_vblank.h>
> > +#include <drm/drm_writeback.h>
> >   #include "msm_drv.h"
> >   #include "msm_mmu.h"
> > @@ -29,6 +31,7 @@
> >   #include "dpu_kms.h"
> >   #include "dpu_plane.h"
> >   #include "dpu_vbif.h"
> > +#include "dpu_writeback.h"
> >   #define CREATE_TRACE_POINTS
> >   #include "dpu_trace.h"
> > @@ -642,6 +645,56 @@ static int _dpu_kms_initialize_displayport(struct 
> > drm_device *dev,
> >       return 0;
> >   }
> > +static int _dpu_kms_initialize_writeback(struct drm_device *dev,
> > +        struct msm_drm_private *priv, struct dpu_kms *dpu_kms)
> > +{
> > +    struct drm_encoder *encoder = NULL;
> > +    struct msm_display_info info;
> > +    int rc, i;
> > +    const u32 *wb_formats;
> > +    int n_formats;
> > +
> > +    encoder = dpu_encoder_init(dev, DRM_MODE_ENCODER_VIRTUAL);
> > +    if (IS_ERR(encoder)) {
> > +        DPU_ERROR("encoder init failed for dsi display\n");
> > +        return PTR_ERR(encoder);
> > +    }
> > +
> > +    memset(&info, 0, sizeof(info));
> > +
> > +    for (i = 0; i < dpu_kms->catalog->wb_count; i++) {
> > +        if (dpu_kms->catalog->wb[i].id == WB_2) {
> > +            wb_formats = dpu_kms->catalog->wb[i].format_list;
> > +            n_formats = dpu_kms->catalog->wb[i].num_formats;
> > +        }
> > +    }
>
> If there is no WB_2 in the catalog, then both wb_formats and n_formats 
> would be unused. Also even if there is no WB_2 you'd still try creating 
> the writeback below.
>
> I'd suggest to move dpu_encoder_init() + dpu_writeback_init() + 
> dpu_encoder_setup() to the separate function. Then you can loop over the 
> catslog->wb[] and once WB_2 is found, call this new function.

Makes sense. Will do this.

> > +
> > +    rc = dpu_writeback_init(dev, encoder, encoder->helper_private, 
> > wb_formats,
> > +            n_formats);
> > +    if (rc) {
> > +        DPU_ERROR("dpu_writeback_init, rc = %d\n", rc);
> > +        drm_encoder_cleanup(encoder);
> > +        return rc;
> > +    }
> > +
> > +    priv->encoders[priv->num_encoders++] = encoder;
> > +
> > +    info.num_of_h_tiles = 1;
> > +    /* use only WB idx 2 instance for DPU */
> > +    info.h_tile_instance[0] = WB_2;
> > +    info.capabilities = MSM_DISPLAY_CAP_HOT_PLUG | MSM_DISPLAY_CAP_EDID;
>
> these two capabilities are unused in the code. I'd suggest to drop them 
> from msm_drv.h at all.

Let me push that as a separate change but will do it for sure as i dont 
see its usage either. Will drop this line from this patch.

> > +    info.intf_type = encoder->encoder_type;
> > +
> > +    rc = dpu_encoder_setup(dev, encoder, &info);
> > +    if (rc) {
> > +        DPU_ERROR("failed to setup DPU encoder %d: rc:%d\n",
> > +                  encoder->base.id, rc);
> > +        return rc;
> > +    }
> > +
> > +    return 0;
> > +}
> > +
> >   /**
> >    * _dpu_kms_setup_displays - create encoders, bridges and connectors
> >    *                           for underlying displays
> > @@ -668,6 +721,15 @@ static int _dpu_kms_setup_displays(struct 
> > drm_device *dev,
> >           return rc;
> >       }
> > +    /* Since WB isn't a driver check the catalog before initializing */
> > +    if (dpu_kms->catalog->wb_count) {
> > +        rc = _dpu_kms_initialize_writeback(dev, priv, dpu_kms);
> > +        if (rc) {
> > +            DPU_ERROR("initialize_WB failed, rc = %d\n", rc);
> > +            return rc;
> > +        }
> > +    }
> > +
> >       return rc;
> >   }