Re: [PATCH] drm/msm/dpu: fix the programming of INTF_CFG2_DATA_HCTL_EN

From: Abhinav Kumar
Date: Wed Jan 31 2024 - 20:14:00 EST




On 1/31/2024 5:05 PM, Dmitry Baryshkov wrote:
On Thu, 1 Feb 2024 at 02:48, Abhinav Kumar <quic_abhinavk@xxxxxxxxxxx> wrote:

Currently INTF_CFG2_DATA_HCTL_EN is coupled with the enablement
of widebus but this is incorrect because we should be enabling
this bit independent of widebus except for cases where compression
is enabled in one pixel per clock mode.

Fix this by making the condition checks more explicit and enabling
INTF_CFG2_DATA_HCTL_EN for all other cases when supported by DPU.

Fixes: 3309a7563971 ("drm/msm/dpu: revise timing engine programming to support widebus feature")
Suggested-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>
Signed-off-by: Abhinav Kumar <quic_abhinavk@xxxxxxxxxxx>

Thank you!

Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>

For the reference: although it is marked as a fix, I'd prefer if this
patch undergoes a full cycle through msm-next rather than
fast-tracking through msm-fixes. This would allow us to catch possible
issues. WDYT?


Yes, I dont plan to take this in -fixes.

Even though this was tested with sc7280, sm8550 before posting, I would like to postpone it for a major release as no use-case other than YUV420 is broken without this.

This will be taken as part of CDM over DP series as we will backout the other change: https://patchwork.freedesktop.org/patch/575963/

---
drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c | 7 +++++++
drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.h | 7 +++++++
.../gpu/drm/msm/disp/dpu1/dpu_encoder_phys_vid.c | 1 +
drivers/gpu/drm/msm/disp/dpu1/dpu_hw_intf.c | 15 +++++++++------
drivers/gpu/drm/msm/disp/dpu1/dpu_hw_intf.h | 1 +
5 files changed, 25 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
index 83380bc92a00..467f874979d5 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
@@ -230,6 +230,13 @@ bool dpu_encoder_is_widebus_enabled(const struct drm_encoder *drm_enc)
return dpu_enc->wide_bus_en;
}

+bool dpu_encoder_is_dsc_enabled(const struct drm_encoder *drm_enc)
+{
+ const struct dpu_encoder_virt *dpu_enc = to_dpu_encoder_virt(drm_enc);
+
+ return dpu_enc->dsc ? true : false;
+}
+
int dpu_encoder_get_crc_values_cnt(const struct drm_encoder *drm_enc)
{
struct dpu_encoder_virt *dpu_enc;
diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.h b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.h
index 4c05fd5e9ed1..fe6b1d312a74 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.h
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.h
@@ -158,6 +158,13 @@ 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_is_dsc_enabled - indicate whether dsc is enabled
+ * for the encoder.
+ * @drm_enc: Pointer to previously created drm encoder structure
+ */
+bool dpu_encoder_is_dsc_enabled(const struct drm_encoder *drm_enc);
+
/**
* 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 d0f56c5c4cce..f562beb6f797 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
@@ -102,6 +102,7 @@ static void drm_mode_to_intf_timing_params(
}

timing->wide_bus_en = dpu_encoder_is_widebus_enabled(phys_enc->parent);
+ timing->compression_en = dpu_encoder_is_dsc_enabled(phys_enc->parent);

/*
* for DP, divide the horizonal parameters by 2 when
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 6bba531d6dc4..965692ef7892 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_intf.c
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_intf.c
@@ -163,13 +163,8 @@ static void dpu_hw_intf_setup_timing_engine(struct dpu_hw_intf *ctx,
hsync_ctl = (hsync_period << 16) | p->hsync_pulse_width;
display_hctl = (hsync_end_x << 16) | hsync_start_x;

- /*
- * DATA_HCTL_EN controls data timing which can be different from
- * video timing. It is recommended to enable it for all cases, except
- * if compression is enabled in 1 pixel per clock mode
- */
if (p->wide_bus_en)
- intf_cfg2 |= INTF_CFG2_DATABUS_WIDEN | INTF_CFG2_DATA_HCTL_EN;
+ intf_cfg2 |= INTF_CFG2_DATABUS_WIDEN;

data_width = p->width;

@@ -229,6 +224,14 @@ static void dpu_hw_intf_setup_timing_engine(struct dpu_hw_intf *ctx,
DPU_REG_WRITE(c, INTF_CONFIG, intf_cfg);
DPU_REG_WRITE(c, INTF_PANEL_FORMAT, panel_format);
if (ctx->cap->features & BIT(DPU_DATA_HCTL_EN)) {
+ /*
+ * DATA_HCTL_EN controls data timing which can be different from
+ * video timing. It is recommended to enable it for all cases, except
+ * if compression is enabled in 1 pixel per clock mode
+ */
+ if (!(p->compression_en && !p->wide_bus_en))
+ intf_cfg2 |= INTF_CFG2_DATA_HCTL_EN;
+
DPU_REG_WRITE(c, INTF_CONFIG2, intf_cfg2);
DPU_REG_WRITE(c, INTF_DISPLAY_DATA_HCTL, display_data_hctl);
DPU_REG_WRITE(c, INTF_ACTIVE_DATA_HCTL, active_data_hctl);
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 0bd57a32144a..6f4c87244f94 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_intf.h
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_intf.h
@@ -33,6 +33,7 @@ struct dpu_hw_intf_timing_params {
u32 hsync_skew;

bool wide_bus_en;
+ bool compression_en;
};

struct dpu_hw_intf_prog_fetch {
--
2.40.1