[v2,3/3] drm/msm/dpu: Add interface support for CRC debugfs

Add support for writing CRC values for the interface block to
the debugfs by calling the necessary MISR setup/collect methods.

Changes since V1:
- Set values_cnt to only include phys with backing hw_intf
- Loop over all drm_encs connected to crtc

Signed-off-by: Jessica Zhang <quic_jesszhan@quicinc.com>
---
 drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c    | 49 ++++++++++++++--
 drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.h    |  3 +
 drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c | 64 +++++++++++++++++++++
 drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.h | 22 +++++++
 4 files changed, 134 insertions(+), 4 deletions(-)

On Wed, 15 Jun 2022 at 00:13, Jessica Zhang <quic_jesszhan@quicinc.com> wrote:
>
> Add support for writing CRC values for the interface block to
> the debugfs by calling the necessary MISR setup/collect methods.
>
> Changes since V1:
> - Set values_cnt to only include phys with backing hw_intf
> - Loop over all drm_encs connected to crtc
>
> Signed-off-by: Jessica Zhang <quic_jesszhan@quicinc.com>
> ---
>  drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c    | 49 ++++++++++++++--
>  drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.h    |  3 +
>  drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c | 64 +++++++++++++++++++++
>  drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.h | 22 +++++++
>  4 files changed, 134 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c
> index 16742a66878e..8c9933b2337f 100644
> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c
> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c
> @@ -79,6 +79,8 @@ static enum dpu_crtc_crc_source dpu_crtc_parse_crc_source(const char *src_name)
>         if (!strcmp(src_name, "auto") ||
>             !strcmp(src_name, "lm"))
>                 return DPU_CRTC_CRC_SOURCE_LAYER_MIXER;
> +       if (!strcmp(src_name, "intf"))
> +               return DPU_CRTC_CRC_SOURCE_INTF;

What about "encoder" / DPU_CRTC_CRC_SOURCE_ENCODER? You basically
offload CRC generation/collection to the dpu_encoder, so I'd ignore
the fact that only INTF's support MISR generation and use a more
generic word here.

>
>         return DPU_CRTC_CRC_SOURCE_INVALID;
>  }
> @@ -99,8 +101,14 @@ static int dpu_crtc_verify_crc_source(struct drm_crtc *crtc,
>                 return -EINVAL;
>         }
>
> -       if (source == DPU_CRTC_CRC_SOURCE_LAYER_MIXER)
> +       if (source == DPU_CRTC_CRC_SOURCE_LAYER_MIXER) {
>                 *values_cnt = crtc_state->num_mixers;
> +       } else if (source == DPU_CRTC_CRC_SOURCE_INTF) {
> +               struct drm_encoder *drm_enc;

Zero values_cnt here.

> +
> +               drm_for_each_encoder_mask(drm_enc, crtc->dev, crtc->state->encoder_mask)
> +                       *values_cnt += dpu_encoder_get_num_phys(drm_enc);
> +       }
>
>         crtc_state->crcs = kcalloc(*values_cnt, sizeof(crtc_state->crcs), GFP_KERNEL);
>
> @@ -123,6 +131,14 @@ static void dpu_crtc_setup_lm_misr(struct dpu_crtc_state *crtc_state)
>         }
>  }
>
> +static void dpu_crtc_setup_encoder_misr(struct drm_crtc *crtc)
> +{
> +       struct drm_encoder *drm_enc;
> +
> +       drm_for_each_encoder_mask(drm_enc, crtc->dev, crtc->state->encoder_mask)
> +               dpu_encoder_setup_misr(drm_enc);
> +}
> +
>  static int dpu_crtc_set_crc_source(struct drm_crtc *crtc, const char *src_name)
>  {
>         enum dpu_crtc_crc_source source = dpu_crtc_parse_crc_source(src_name);
> @@ -175,6 +191,8 @@ static int dpu_crtc_set_crc_source(struct drm_crtc *crtc, const char *src_name)
>
>         if (source == DPU_CRTC_CRC_SOURCE_LAYER_MIXER)
>                 dpu_crtc_setup_lm_misr(crtc_state);
> +       else if (source == DPU_CRTC_CRC_SOURCE_INTF)
> +               dpu_crtc_setup_encoder_misr(crtc);

else?

>
>  cleanup:
>         drm_modeset_unlock(&crtc->mutex);
> @@ -220,11 +238,31 @@ static int dpu_crtc_get_lm_crc(struct drm_crtc *crtc, struct dpu_crtc_state *crt
>                         drm_crtc_accurate_vblank_count(crtc), crtc_state->crcs);
>  }
>
> -static int dpu_crtc_get_crc(struct drm_crtc *crtc)
> +static int dpu_crtc_get_encoder_crc(struct drm_crtc *crtc)
>  {
> -       struct dpu_crtc_state *crtc_state;
> +       struct drm_encoder *drm_enc;
> +       struct dpu_crtc_state *crtc_state = to_dpu_crtc_state(crtc->state);
> +       int rc, pos = 0;
>
> -       crtc_state = to_dpu_crtc_state(crtc->state);
> +       drm_for_each_encoder_mask(drm_enc, crtc->dev, crtc->state->encoder_mask) {
> +               rc = dpu_encoder_get_crc(drm_enc, crtc_state->crcs, pos);
> +               if (rc < 0) {
> +                       if (rc != -ENODATA)
> +                               DRM_DEBUG_DRIVER("MISR read failed\n");
> +
> +                       return rc;
> +               }
> +
> +               pos += rc;
> +       }
> +
> +       return drm_crtc_add_crc_entry(crtc, true,
> +                       drm_crtc_accurate_vblank_count(crtc), crtc_state->crcs);
> +}
> +
> +static int dpu_crtc_get_crc(struct drm_crtc *crtc)
> +{
> +       struct dpu_crtc_state *crtc_state = to_dpu_crtc_state(crtc->state);

Unnecessary change here. Please move it to the patch 1, which
refactors this function.

>
>         /* Skip first 2 frames in case of "uncooked" CRCs */
>         if (crtc_state->crc_frame_skip_count < 2) {
> @@ -235,6 +273,9 @@ static int dpu_crtc_get_crc(struct drm_crtc *crtc)
>         if (crtc_state->crc_source == DPU_CRTC_CRC_SOURCE_LAYER_MIXER)
>                 return dpu_crtc_get_lm_crc(crtc, crtc_state);
>
> +       if (crtc_state->crc_source == DPU_CRTC_CRC_SOURCE_INTF)
> +               return dpu_crtc_get_encoder_crc(crtc);
> +
>         return 0;
>  }
>
> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.h b/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.h
> index 4bf45e3343ef..5db84ea796db 100644
> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.h
> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.h
> @@ -1,5 +1,6 @@
>  /* SPDX-License-Identifier: GPL-2.0-only */
>  /*
> + * Copyright (c) 2022 Qualcomm Innovation Center, Inc. All rights reserved.
>   * Copyright (c) 2015-2021 The Linux Foundation. All rights reserved.
>   * Copyright (C) 2013 Red Hat
>   * Author: Rob Clark <robdclark@gmail.com>
> @@ -73,11 +74,13 @@ struct dpu_crtc_smmu_state_data {
>   * enum dpu_crtc_crc_source: CRC source
>   * @DPU_CRTC_CRC_SOURCE_NONE: no source set
>   * @DPU_CRTC_CRC_SOURCE_LAYER_MIXER: CRC in layer mixer
> + * @DPU_CRTC_CRC_SOURCE_INTF: CRC in phys interface
>   * @DPU_CRTC_CRC_SOURCE_INVALID: Invalid source
>   */
>  enum dpu_crtc_crc_source {
>         DPU_CRTC_CRC_SOURCE_NONE = 0,
>         DPU_CRTC_CRC_SOURCE_LAYER_MIXER,
> +       DPU_CRTC_CRC_SOURCE_INTF,
>         DPU_CRTC_CRC_SOURCE_MAX,
>         DPU_CRTC_CRC_SOURCE_INVALID = -1
>  };
> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
> index 52516eb20cb8..2cbfed5c627e 100644
> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
> @@ -14,6 +14,7 @@
>
>  #include <drm/drm_crtc.h>
>  #include <drm/drm_file.h>
> +#include <drm/drm_vblank.h>

Why?

>  #include <drm/drm_probe_helper.h>
>
>  #include "msm_drv.h"
> @@ -225,6 +226,69 @@ bool dpu_encoder_is_widebus_enabled(const struct drm_encoder *drm_enc)
>         return dpu_enc->wide_bus_en;
>  }
>
> +int dpu_encoder_get_num_phys(const struct drm_encoder *drm_enc)

The function name is misleading. It doesn't return the number of phys.
It returns a number of hw_intfs. And in reality you'd like to get the
number of crc entries supported. If at some point WB (or any other
possible dpu_encoder backend) gains support for CRC, we won't have to
change the name.  Please consider adjusting it.

> +{
> +       struct dpu_encoder_virt *dpu_enc;
> +       int i, num_intf = 0;
> +
> +       dpu_enc = to_dpu_encoder_virt(drm_enc);
> +
> +       for (i = 0; i < dpu_enc->num_phys_encs; i++) {
> +               struct dpu_encoder_phys *phys = dpu_enc->phys_encs[i];
> +
> +               if (phys->hw_intf)
> +                       num_intf++;

You have to check for hw_intf->ops.setup_misr too.

> +       }
> +
> +       return num_intf;
> +}
> +
> +void dpu_encoder_setup_misr(const struct drm_encoder *drm_enc)
> +{
> +       struct dpu_encoder_virt *dpu_enc;
> +
> +       int i;
> +
> +       dpu_enc = to_dpu_encoder_virt(drm_enc);
> +
> +       for (i = 0; i < dpu_enc->num_phys_encs; i++) {
> +               struct dpu_encoder_phys *phys = dpu_enc->phys_encs[i];
> +
> +               if (!phys->hw_intf || !phys->hw_intf->ops.setup_misr)
> +                       continue;
> +
> +               phys->hw_intf->ops.setup_misr(phys->hw_intf, true, 1);
> +       }
> +}
> +
> +int dpu_encoder_get_crc(const struct drm_encoder *drm_enc, u32 *crcs, int pos)
> +{
> +       struct dpu_encoder_virt *dpu_enc;
> +
> +       int i, rc = 0, entries_added = 0;
> +
> +       if (!drm_enc->crtc) {
> +               DRM_ERROR("no crtc found for encoder %d\n", drm_enc->index);
> +               return -EINVAL;
> +       }
> +
> +       dpu_enc = to_dpu_encoder_virt(drm_enc);
> +
> +       for (i = 0; i < dpu_enc->num_phys_encs; i++) {
> +               struct dpu_encoder_phys *phys = dpu_enc->phys_encs[i];
> +
> +               if (!phys->hw_intf || !phys->hw_intf->ops.collect_misr)
> +                       continue;
> +
> +               rc = phys->hw_intf->ops.collect_misr(phys->hw_intf, &crcs[pos + i]);

No, you should be indexing the crcs with entries_added rather than i.

> +               if (rc)
> +                       return rc;
> +               entries_added++;
> +       }
> +
> +       return entries_added;
> +}
> +
>  static void _dpu_encoder_setup_dither(struct dpu_hw_pingpong *hw_pp, unsigned bpc)
>  {
>         struct dpu_hw_dither_cfg dither_cfg = { 0 };
> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.h b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.h
> index 781d41c91994..375370029cb9 100644
> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.h
> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.h
> @@ -1,5 +1,6 @@
>  /* SPDX-License-Identifier: GPL-2.0-only */
>  /*
> + * Copyright (c) 2022 Qualcomm Innovation Center, Inc. All rights reserved.
>   * Copyright (c) 2015-2018, The Linux Foundation. All rights reserved.
>   * Copyright (C) 2013 Red Hat
>   * Author: Rob Clark <robdclark@gmail.com>
> @@ -174,6 +175,27 @@ 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_num_phys - get number of physical encoders contained in virtual
> + *                            encoder
> + * @drm_enc:    Pointer to previously created drm encoder structure
> + * Returns:     Number of physical encoders for given drm encoder
> + */
> +int dpu_encoder_get_num_phys(const struct drm_encoder *drm_enc);
> +
> +/**
> + * dpu_encoder_setup_misr - enable misr calculations
> + * @drm_enc:    Pointer to previously created drm encoder structure
> + */
> +void dpu_encoder_setup_misr(const struct drm_encoder *drm_encoder);
> +
> +/**
> + * dpu_encoder_get_crc - get the crc value from interface blocks
> + * @drm_enc:    Pointer to previously created drm encoder structure
> + * Returns:     0 on success, error otherwise
> + */
> +int dpu_encoder_get_crc(const struct drm_encoder *drm_enc, u32 *crcs, int pos);
> +
>  /**
>   * dpu_encoder_use_dsc_merge - returns true if the encoder uses DSC merge topology.
>   * @drm_enc:    Pointer to previously created drm encoder structure
> --
> 2.35.1
>