Re: [PATCH v3 2/4] drm/msm/dpu: Enable widebus for DSI INTF

From: Jessica Zhang
Date: Mon Aug 07 2023 - 18:21:59 EST




On 8/2/2023 12:39 PM, Marijn Suijten wrote:
On 2023-08-02 11:08:49, Jessica Zhang wrote:
DPU supports a data-bus widen mode for DSI INTF.

Enable this mode for all supported chipsets if widebus is enabled for DSI.

Signed-off-by: Jessica Zhang <quic_jesszhan@xxxxxxxxxxx>
---
drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c | 11 ++++++++---
drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_cmd.c | 4 +++-
drivers/gpu/drm/msm/disp/dpu1/dpu_hw_intf.c | 3 +++
drivers/gpu/drm/msm/disp/dpu1/dpu_hw_intf.h | 1 +
drivers/gpu/drm/msm/msm_drv.h | 6 +++++-
5 files changed, 20 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 3dcd37c48aac..de08aad39e15 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
@@ -1196,15 +1196,20 @@ static void dpu_encoder_virt_atomic_enable(struct drm_encoder *drm_enc,
struct drm_display_mode *cur_mode = NULL;
struct msm_drm_private *priv = drm_enc->dev->dev_private;
struct msm_display_info *disp_info;
+ int index;
dpu_enc = to_dpu_encoder_virt(drm_enc);
disp_info = &dpu_enc->disp_info;
+ disp_info = &dpu_enc->disp_info;
+ index = disp_info->h_tile_instance[0];
+
dpu_enc->dsc = dpu_encoder_get_dsc_config(drm_enc);
- if (disp_info->intf_type == INTF_DP)
- dpu_enc->wide_bus_en = msm_dp_wide_bus_available(
- priv->dp[disp_info->h_tile_instance[0]]);
+ if (disp_info->intf_type == INTF_DSI)
+ dpu_enc->wide_bus_en = msm_dsi_is_widebus_enabled(priv->dsi[index]);
+ else if (disp_info->intf_type == INTF_DP)
+ dpu_enc->wide_bus_en = msm_dp_wide_bus_available(priv->dp[index]);

This inconsistency really is killing. wide_bus vs widebus, and one
function has an is_ while the other does not.

Hi Marijn,

Acked. Will change the DSI function name to match DP.


mutex_lock(&dpu_enc->enc_lock);
cur_mode = &dpu_enc->base.crtc->state->adjusted_mode;
diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_cmd.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_cmd.c
index df88358e7037..dace6168be2d 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_cmd.c
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_cmd.c
@@ -69,8 +69,10 @@ static void _dpu_encoder_phys_cmd_update_intf_cfg(
phys_enc->hw_intf,
phys_enc->hw_pp->idx);
- if (intf_cfg.dsc != 0)
+ if (intf_cfg.dsc != 0) {
cmd_mode_cfg.data_compress = true;
+ cmd_mode_cfg.wide_bus_en = dpu_encoder_is_widebus_enabled(phys_enc->parent);
+ }
if (phys_enc->hw_intf->ops.program_intf_cmd_cfg)
phys_enc->hw_intf->ops.program_intf_cmd_cfg(phys_enc->hw_intf, &cmd_mode_cfg);
diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_intf.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_intf.c
index 8ec6505d9e78..dc6f3febb574 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_intf.c
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_intf.c
@@ -521,6 +521,9 @@ static void dpu_hw_intf_program_intf_cmd_cfg(struct dpu_hw_intf *ctx,
if (cmd_mode_cfg->data_compress)
intf_cfg2 |= INTF_CFG2_DCE_DATA_COMPRESS;
+ if (cmd_mode_cfg->wide_bus_en)
+ intf_cfg2 |= INTF_CFG2_DATABUS_WIDEN;
+
DPU_REG_WRITE(&ctx->hw, INTF_CONFIG2, intf_cfg2);
}
diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_intf.h b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_intf.h
index 77f80531782b..c539025c418b 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_intf.h
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_intf.h
@@ -50,6 +50,7 @@ struct dpu_hw_intf_status {
struct dpu_hw_intf_cmd_mode_cfg {
u8 data_compress; /* enable data compress between dpu and dsi */
+ u8 wide_bus_en; /* enable databus widen mode */

Any clue why these weren't just bool types? These suffix-comments also
aren't adhering to the kerneldoc format, or is there a different
variant?

It seems that the `u8` declaration and comment docs were meant to mirror the other dpu_hw_intf_* structs [1]

[1] https://elixir.bootlin.com/linux/v6.5-rc5/source/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_intf.h#L44


};
/**
diff --git a/drivers/gpu/drm/msm/msm_drv.h b/drivers/gpu/drm/msm/msm_drv.h
index 9d9d5e009163..e4f706b16aad 100644
--- a/drivers/gpu/drm/msm/msm_drv.h
+++ b/drivers/gpu/drm/msm/msm_drv.h
@@ -344,6 +344,7 @@ void msm_dsi_snapshot(struct msm_disp_state *disp_state, struct msm_dsi *msm_dsi
bool msm_dsi_is_cmd_mode(struct msm_dsi *msm_dsi);
bool msm_dsi_is_bonded_dsi(struct msm_dsi *msm_dsi);
bool msm_dsi_is_master_dsi(struct msm_dsi *msm_dsi);
+bool msm_dsi_is_widebus_enabled(struct msm_dsi *msm_dsi);
struct drm_dsc_config *msm_dsi_get_dsc_config(struct msm_dsi *msm_dsi);
#else
static inline void __init msm_dsi_register(void)
@@ -373,7 +374,10 @@ static inline bool msm_dsi_is_master_dsi(struct msm_dsi *msm_dsi)
{
return false;
}
-
+static inline bool msm_dsi_is_widebus_enabled(struct msm_dsi *msm_dsi)
+{
+ return false;
+}

Only this default inline implementation is defined, but the function is
declared in this commit. Since there's no real functional
implementation yet your commit should clarify that it comes later (in a
followup commit in the same series? I can't know because I am reviewing
this series linearly from start to finish...) or reorder the patches so
that this lack of clarity is circumvented entirely.

This was so that there wouldn't be a compiler error in cases where CONFIG_MSM_DSI=n (since DPU support is added before DSI support).

Thanks,

Jessica Zhang


- Marijn

static inline struct drm_dsc_config *msm_dsi_get_dsc_config(struct msm_dsi *msm_dsi)
{
return NULL;

--
2.41.0