[PATCH] drm/msm/dpu: Add CRC support for DPU

[PATCH] drm/msm/dpu: Add CRC support for DPU

[Jessica Zhang]

Add CRC support to DPU, which is currently not supported by
this driver. Only supports CRC for CRTC for now, but will extend support
to other blocks later on.

Tested on Qualcomm RB3 (debian, sdm845)

Signed-off-by: Jessica Zhang <jesszhan@codeaurora.org>
---
 drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c    | 169 +++++++++++++++++++-
 drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.h    |  20 ++-
 drivers/gpu/drm/msm/disp/dpu1/dpu_hw_lm.c   |  46 +++++-
 drivers/gpu/drm/msm/disp/dpu1/dpu_hw_lm.h   |  13 +-
 drivers/gpu/drm/msm/disp/dpu1/dpu_hw_util.h |   9 +-
 5 files changed, 251 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c
index 768012243b44..6ebf989c4e67 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c
@@ -1,6 +1,6 @@
 // SPDX-License-Identifier: GPL-2.0-only
 /*
- * Copyright (c) 2014-2018 The Linux Foundation. All rights reserved.
+ * Copyright (c) 2014-2021 The Linux Foundation. All rights reserved.
  * Copyright (C) 2013 Red Hat
  * Author: Rob Clark <robdclark@gmail.com>
  */
@@ -70,6 +70,121 @@ static struct drm_encoder *get_encoder_from_crtc(struct drm_crtc *crtc)
 	return NULL;
 }
 
+static enum dpu_crtc_crc_source dpu_crtc_parse_crc_source(const char *src_name)
+{
+	if (!src_name || !strcmp(src_name, "none"))
+		return DPU_CRTC_CRC_SOURCE_NONE;
+	if (!strcmp(src_name, "auto") || !strcmp(src_name, "lm"))
+		return DPU_CRTC_CRC_SOURCE_LAYER_MIXER;
+
+	return DPU_CRTC_CRC_SOURCE_INVALID;
+}
+
+static bool dpu_crtc_is_valid_crc_source(enum dpu_crtc_crc_source source)
+{
+	return (source > DPU_CRTC_CRC_SOURCE_NONE &&
+		source < DPU_CRTC_CRC_SOURCE_MAX);
+}
+
+int dpu_crtc_verify_crc_source(struct drm_crtc *crtc, const char *src_name, size_t *values_cnt)
+{
+	enum dpu_crtc_crc_source source = dpu_crtc_parse_crc_source(src_name);
+	struct dpu_crtc_state *crtc_state = to_dpu_crtc_state(crtc->state);
+
+	if (source < 0) {
+		DRM_DEBUG_DRIVER("Invalid source %s for CRTC%d\n", src_name, crtc->index);
+		return -EINVAL;
+	}
+
+	if (source == DPU_CRTC_CRC_SOURCE_LAYER_MIXER)
+		*values_cnt = crtc_state->num_mixers;
+
+	return 0;
+}
+
+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);
+	enum dpu_crtc_crc_source current_source;
+	struct drm_crtc_commit *commit;
+	struct dpu_crtc_state *crtc_state;
+	struct drm_device *drm_dev = crtc->dev;
+	struct dpu_crtc *dpu_crtc = to_dpu_crtc(crtc);
+	struct dpu_crtc_mixer *m;
+
+	bool was_enabled;
+	bool enable = false;
+	int i, ret = 0;
+
+	if (source < 0) {
+		DRM_DEBUG_DRIVER("Invalid CRC source %s for CRTC%d\n", src_name, crtc->index);
+		return -EINVAL;
+	}
+
+	ret = drm_modeset_lock(&crtc->mutex, NULL);
+
+	if (ret)
+		return ret;
+
+	/* Wait for any pending commits to finish */
+	spin_lock(&crtc->commit_lock);
+	commit = list_first_entry_or_null(&crtc->commit_list, struct drm_crtc_commit, commit_entry);
+
+	if (commit)
+		drm_crtc_commit_get(commit);
+	spin_unlock(&crtc->commit_lock);
+
+	if (commit) {
+		ret = wait_for_completion_interruptible_timeout(&commit->hw_done, 10 * HZ);
+
+		if (ret)
+			goto cleanup;
+	}
+
+	enable = dpu_crtc_is_valid_crc_source(source);
+	crtc_state = to_dpu_crtc_state(crtc->state);
+
+	spin_lock_irq(&drm_dev->event_lock);
+	current_source = dpu_crtc->crc_source;
+	spin_unlock_irq(&drm_dev->event_lock);
+
+	was_enabled = !(current_source == DPU_CRTC_CRC_SOURCE_NONE);
+
+	if (!was_enabled && enable) {
+		ret = drm_crtc_vblank_get(crtc);
+
+		if (ret)
+			goto cleanup;
+
+	} else if (was_enabled && !enable) {
+		drm_crtc_vblank_put(crtc);
+	}
+
+	spin_lock_irq(&drm_dev->event_lock);
+	dpu_crtc->crc_source = source;
+	spin_unlock_irq(&drm_dev->event_lock);
+
+	crtc_state->skip_count = 0;
+
+	for (i = 0; i < crtc_state->num_mixers; ++i) {
+		m = &crtc_state->mixers[i];
+
+		if (!m->hw_lm || !m->hw_lm->ops.collect_misr || !m->hw_lm->ops.setup_misr)
+			continue;
+
+		/* Calculate MISR over 1 frame */
+		m->hw_lm->ops.setup_misr(m->hw_lm, true, 1);
+	}
+
+
+cleanup:
+	if (commit)
+		drm_crtc_commit_put(commit);
+	drm_modeset_unlock(&crtc->mutex);
+
+	return ret;
+}
+
 static u32 dpu_crtc_get_vblank_counter(struct drm_crtc *crtc)
 {
 	struct drm_encoder *encoder;
@@ -83,6 +198,52 @@ static u32 dpu_crtc_get_vblank_counter(struct drm_crtc *crtc)
 	return dpu_encoder_get_frame_count(encoder);
 }
 
+
+static void dpu_crtc_get_crc(struct drm_crtc *crtc)
+{
+	struct dpu_crtc *dpu_crtc;
+	struct dpu_crtc_state *crtc_state;
+	struct dpu_crtc_mixer *m;
+	u32 *crcs;
+
+	int i = 0;
+	int rc = 0;
+
+	if (!crtc) {
+		DPU_ERROR("Invalid crtc\n");
+		return;
+	}
+
+	crtc_state = to_dpu_crtc_state(crtc->state);
+	dpu_crtc = to_dpu_crtc(crtc);
+	crcs = kcalloc(crtc_state->num_mixers, sizeof(*crcs), GFP_KERNEL);
+
+	/* Skip first 2 frames in case of "uncooked" CRCs */
+	if (crtc_state->skip_count < 2) {
+		crtc_state->skip_count++;
+		return;
+	}
+
+	for (i = 0; i < crtc_state->num_mixers; ++i) {
+
+		m = &crtc_state->mixers[i];
+
+		if (!m->hw_lm || !m->hw_lm->ops.collect_misr
+			|| !m->hw_lm->ops.setup_misr)
+			continue;
+
+		rc = m->hw_lm->ops.collect_misr(m->hw_lm, &crcs[i]);
+
+		if (rc) {
+			DRM_DEBUG_DRIVER("MISR read failed\n");
+			return;
+		}
+	}
+
+	drm_crtc_add_crc_entry(crtc, true,
+			drm_crtc_accurate_vblank_count(crtc), crcs);
+}
+
 static bool dpu_crtc_get_scanout_position(struct drm_crtc *crtc,
 					   bool in_vblank_irq,
 					   int *vpos, int *hpos,
@@ -389,6 +550,10 @@ void dpu_crtc_vblank_callback(struct drm_crtc *crtc)
 		dpu_crtc->vblank_cb_time = ktime_get();
 	else
 		dpu_crtc->vblank_cb_count++;
+
+	if (dpu_crtc_is_valid_crc_source(dpu_crtc->crc_source))
+		dpu_crtc_get_crc(crtc);
+
 	drm_crtc_handle_vblank(crtc);
 	trace_dpu_crtc_vblank_cb(DRMID(crtc));
 }
@@ -1332,6 +1497,8 @@ static const struct drm_crtc_funcs dpu_crtc_funcs = {
 	.atomic_destroy_state = dpu_crtc_destroy_state,
 	.late_register = dpu_crtc_late_register,
 	.early_unregister = dpu_crtc_early_unregister,
+	.verify_crc_source = dpu_crtc_verify_crc_source,
+	.set_crc_source = dpu_crtc_set_crc_source,
 	.enable_vblank  = msm_crtc_enable_vblank,
 	.disable_vblank = msm_crtc_disable_vblank,
 	.get_vblank_timestamp = drm_crtc_vblank_helper_get_vblank_timestamp,
diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.h b/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.h
index cec3474340e8..e9940f1d5d15 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.h
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.h
@@ -1,6 +1,6 @@
 /* SPDX-License-Identifier: GPL-2.0-only */
 /*
- * Copyright (c) 2015-2018 The Linux Foundation. All rights reserved.
+ * Copyright (c) 2015-2021 The Linux Foundation. All rights reserved.
  * Copyright (C) 2013 Red Hat
  * Author: Rob Clark <robdclark@gmail.com>
  */
@@ -69,6 +69,19 @@ struct dpu_crtc_smmu_state_data {
 	uint32_t transition_error;
 };
 
+/**
+ * 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_INVALID: Invalid source
+ */
+enum dpu_crtc_crc_source {
+	DPU_CRTC_CRC_SOURCE_NONE = 0,
+	DPU_CRTC_CRC_SOURCE_LAYER_MIXER,
+	DPU_CRTC_CRC_SOURCE_MAX,
+	DPU_CRTC_CRC_SOURCE_INVALID = -1
+};
+
 /**
  * struct dpu_crtc_mixer: stores the map for each virtual pipeline in the CRTC
  * @hw_lm:	LM HW Driver context
@@ -139,6 +152,7 @@ struct dpu_crtc_frame_event {
  * @event_lock    : Spinlock around event handling code
  * @phandle: Pointer to power handler
  * @cur_perf      : current performance committed to clock/bandwidth driver
+ * @crc_source    : CRC source
  */
 struct dpu_crtc {
 	struct drm_crtc base;
@@ -171,8 +185,8 @@ struct dpu_crtc {
 	spinlock_t event_lock;
 
 	struct dpu_core_perf_params cur_perf;
-
 	struct dpu_crtc_smmu_state_data smmu_state;
+	enum dpu_crtc_crc_source crc_source;
 };
 
 #define to_dpu_crtc(x) container_of(x, struct dpu_crtc, base)
@@ -210,6 +224,8 @@ struct dpu_crtc_state {
 
 	u32 num_ctls;
 	struct dpu_hw_ctl *hw_ctls[CRTC_DUAL_MIXERS];
+
+	int skip_count;
 };
 
 #define to_dpu_crtc_state(x) \
diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_lm.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_lm.c
index cb6bb7a22c15..679b3728e891 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_lm.c
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_lm.c
@@ -1,5 +1,6 @@
 // SPDX-License-Identifier: GPL-2.0-only
-/* Copyright (c) 2015-2018, The Linux Foundation. All rights reserved.
+/*
+ * Copyright (c) 2015-2021, The Linux Foundation. All rights reserved.
  */
 
 #include "dpu_kms.h"
@@ -24,6 +25,9 @@
 #define LM_BLEND0_FG_ALPHA               0x04
 #define LM_BLEND0_BG_ALPHA               0x08
 
+#define LM_MISR_CTRL                     0x310
+#define LM_MISR_SIGNATURE                0x314
+
 static const struct dpu_lm_cfg *_lm_offset(enum dpu_lm mixer,
 		const struct dpu_mdss_cfg *m,
 		void __iomem *addr,
@@ -96,6 +100,44 @@ static void dpu_hw_lm_setup_border_color(struct dpu_hw_mixer *ctx,
 	}
 }
 
+static void dpu_hw_lm_setup_misr(struct dpu_hw_mixer *ctx, bool enable, u32 frame_count)
+{
+	struct dpu_hw_blk_reg_map *c = &ctx->hw;
+	u32 config = 0;
+
+	DPU_REG_WRITE(c, LM_MISR_CTRL, MISR_CTRL_STATUS_CLEAR);
+
+	/* Clear MISR data */
+	wmb();
+
+	if (enable)
+		config = (frame_count & MISR_FRAME_COUNT_MASK) |
+			MISR_CTRL_ENABLE | INTF_MISR_CTRL_FREE_RUN_MASK;
+
+	DPU_REG_WRITE(c, LM_MISR_CTRL, config);
+}
+
+static int dpu_hw_lm_collect_misr(struct dpu_hw_mixer *ctx, u32 *misr_value)
+{
+	struct dpu_hw_blk_reg_map *c = &ctx->hw;
+	u32 ctrl = 0;
+
+	if (!misr_value)
+		return -EINVAL;
+
+	ctrl = DPU_REG_READ(c, LM_MISR_CTRL);
+
+	if (!(ctrl & MISR_CTRL_ENABLE))
+		return -EINVAL;
+
+	if (!(ctrl & MISR_CTRL_STATUS))
+		return -EINVAL;
+
+	*misr_value = DPU_REG_READ(c, LM_MISR_SIGNATURE);
+
+	return 0;
+}
+
 static void dpu_hw_lm_setup_blend_config_sdm845(struct dpu_hw_mixer *ctx,
 	u32 stage, u32 fg_alpha, u32 bg_alpha, u32 blend_op)
 {
@@ -158,6 +200,8 @@ static void _setup_mixer_ops(const struct dpu_mdss_cfg *m,
 		ops->setup_blend_config = dpu_hw_lm_setup_blend_config;
 	ops->setup_alpha_out = dpu_hw_lm_setup_color3;
 	ops->setup_border_color = dpu_hw_lm_setup_border_color;
+	ops->setup_misr = dpu_hw_lm_setup_misr;
+	ops->collect_misr = dpu_hw_lm_collect_misr;
 }
 
 struct dpu_hw_mixer *dpu_hw_lm_init(enum dpu_lm idx,
diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_lm.h b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_lm.h
index 4a6b2de19ef6..d8052fb2d5da 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_lm.h
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_lm.h
@@ -1,5 +1,6 @@
 /* SPDX-License-Identifier: GPL-2.0-only */
-/* Copyright (c) 2015-2018, The Linux Foundation. All rights reserved.
+/*
+ * Copyright (c) 2015-2021, The Linux Foundation. All rights reserved.
  */
 
 #ifndef _DPU_HW_LM_H
@@ -53,6 +54,16 @@ struct dpu_hw_lm_ops {
 	void (*setup_border_color)(struct dpu_hw_mixer *ctx,
 		struct dpu_mdss_color *color,
 		u8 border_en);
+
+	/**
+	 * setup_misr: Enable/disable MISR
+	 */
+	void (*setup_misr)(struct dpu_hw_mixer *ctx, bool enable, u32 frame_count);
+
+	/**
+	 * collect_misr: Read MISR signature
+	 */
+	int (*collect_misr)(struct dpu_hw_mixer *ctx, u32 *misr_value);
 };
 
 struct dpu_hw_mixer {
diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_util.h b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_util.h
index ff3cffde84cd..506d4af7d018 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_util.h
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_util.h
@@ -1,5 +1,6 @@
 /* SPDX-License-Identifier: GPL-2.0-only */
-/* Copyright (c) 2015-2018, The Linux Foundation. All rights reserved.
+/*
+ * Copyright (c) 2015-2021, The Linux Foundation. All rights reserved.
  */
 
 #ifndef _DPU_HW_UTIL_H
@@ -309,6 +310,12 @@ int dpu_reg_read(struct dpu_hw_blk_reg_map *c, u32 reg_off);
 #define DPU_REG_WRITE(c, off, val) dpu_reg_write(c, off, val, #off)
 #define DPU_REG_READ(c, off) dpu_reg_read(c, off)
 
+#define MISR_FRAME_COUNT_MASK           0xFF
+#define MISR_CTRL_ENABLE                BIT(8)
+#define MISR_CTRL_STATUS                BIT(9)
+#define MISR_CTRL_STATUS_CLEAR          BIT(10)
+#define INTF_MISR_CTRL_FREE_RUN_MASK    BIT(31)
+
 void *dpu_hw_util_get_dir(void);
 
 void dpu_hw_setup_scaler3(struct dpu_hw_blk_reg_map *c,
-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project

Re: [PATCH] drm/msm/dpu: Add CRC support for DPU

[Dmitry Baryshkov]

On 12/10/2021 02:41, Jessica Zhang wrote:
> Add CRC support to DPU, which is currently not supported by
> this driver. Only supports CRC for CRTC for now, but will extend support
> to other blocks later on.
> 
> Tested on Qualcomm RB3 (debian, sdm845)
> 
> Signed-off-by: Jessica Zhang <jesszhan@codeaurora.org>
> ---
>   drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c    | 169 +++++++++++++++++++-
>   drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.h    |  20 ++-
>   drivers/gpu/drm/msm/disp/dpu1/dpu_hw_lm.c   |  46 +++++-
>   drivers/gpu/drm/msm/disp/dpu1/dpu_hw_lm.h   |  13 +-
>   drivers/gpu/drm/msm/disp/dpu1/dpu_hw_util.h |   9 +-
>   5 files changed, 251 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c
> index 768012243b44..6ebf989c4e67 100644
> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c
> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c
> @@ -1,6 +1,6 @@
>   // SPDX-License-Identifier: GPL-2.0-only
>   /*
> - * Copyright (c) 2014-2018 The Linux Foundation. All rights reserved.
> + * Copyright (c) 2014-2021 The Linux Foundation. All rights reserved.
>    * Copyright (C) 2013 Red Hat
>    * Author: Rob Clark <robdclark@gmail.com>
>    */
> @@ -70,6 +70,121 @@ static struct drm_encoder *get_encoder_from_crtc(struct drm_crtc *crtc)
>   	return NULL;
>   }
>   
> +static enum dpu_crtc_crc_source dpu_crtc_parse_crc_source(const char *src_name)
> +{
> +	if (!src_name || !strcmp(src_name, "none"))
> +		return DPU_CRTC_CRC_SOURCE_NONE;

Newlines after || please. this would improve readability.

> +	if (!strcmp(src_name, "auto") || !strcmp(src_name, "lm"))
> +		return DPU_CRTC_CRC_SOURCE_LAYER_MIXER;
> +
> +	return DPU_CRTC_CRC_SOURCE_INVALID;
> +}
> +
> +static bool dpu_crtc_is_valid_crc_source(enum dpu_crtc_crc_source source)
> +{
> +	return (source > DPU_CRTC_CRC_SOURCE_NONE &&
> +		source < DPU_CRTC_CRC_SOURCE_MAX);
> +}
> +
> +int dpu_crtc_verify_crc_source(struct drm_crtc *crtc, const char *src_name, size_t *values_cnt)
> +{
> +	enum dpu_crtc_crc_source source = dpu_crtc_parse_crc_source(src_name);
> +	struct dpu_crtc_state *crtc_state = to_dpu_crtc_state(crtc->state);
> +
> +	if (source < 0) {

Just use dpu_crtc_is_valid_crtc_source() here.

> +		DRM_DEBUG_DRIVER("Invalid source %s for CRTC%d\n", src_name, crtc->index);
> +		return -EINVAL;
> +	}
> +
> +	if (source == DPU_CRTC_CRC_SOURCE_LAYER_MIXER)
> +		*values_cnt = crtc_state->num_mixers;
> +
> +	return 0;
> +}
> +
> +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);
> +	enum dpu_crtc_crc_source current_source;
> +	struct drm_crtc_commit *commit;
> +	struct dpu_crtc_state *crtc_state;
> +	struct drm_device *drm_dev = crtc->dev;
> +	struct dpu_crtc *dpu_crtc = to_dpu_crtc(crtc);
> +	struct dpu_crtc_mixer *m;
> +
> +	bool was_enabled;
> +	bool enable = false;
> +	int i, ret = 0;
> +
> +	if (source < 0) {
> +		DRM_DEBUG_DRIVER("Invalid CRC source %s for CRTC%d\n", src_name, crtc->index);
> +		return -EINVAL;
> +	}
> +
> +	ret = drm_modeset_lock(&crtc->mutex, NULL);
> +
> +	if (ret)
> +		return ret;
> +
> +	/* Wait for any pending commits to finish */
> +	spin_lock(&crtc->commit_lock);
> +	commit = list_first_entry_or_null(&crtc->commit_list, struct drm_crtc_commit, commit_entry);
> +
> +	if (commit)
> +		drm_crtc_commit_get(commit);
> +	spin_unlock(&crtc->commit_lock);
> +
> +	if (commit) {
> +		ret = wait_for_completion_interruptible_timeout(&commit->hw_done, 10 * HZ);
> +
> +		if (ret)
> +			goto cleanup;
> +	}

AMD drivers waits for the commit to finish, because it's commit tail can 
modify CRC-related registers. It unique, no other drivers seem to do 
this kind of wait. Why do we need to do it? And if we really need, I'd 
prefer to have this code in some kind of DRM helper function.


> +	enable = dpu_crtc_is_valid_crc_source(source);
> +	crtc_state = to_dpu_crtc_state(crtc->state);
> +
> +	spin_lock_irq(&drm_dev->event_lock);
> +	current_source = dpu_crtc->crc_source;
> +	spin_unlock_irq(&drm_dev->event_lock);
> +
> +	was_enabled = !(current_source == DPU_CRTC_CRC_SOURCE_NONE);

current_source != DPU_CRTC_CRC_SOURCE_NONE would be easier.

> +
> +	if (!was_enabled && enable) {
> +		ret = drm_crtc_vblank_get(crtc);
> +
> +		if (ret)
> +			goto cleanup;
> +
> +	} else if (was_enabled && !enable) {
> +		drm_crtc_vblank_put(crtc);
> +	}
> +
> +	spin_lock_irq(&drm_dev->event_lock);
> +	dpu_crtc->crc_source = source;
> +	spin_unlock_irq(&drm_dev->event_lock);
> +
> +	crtc_state->skip_count = 0;
> +
> +	for (i = 0; i < crtc_state->num_mixers; ++i) {
> +		m = &crtc_state->mixers[i];
> +
> +		if (!m->hw_lm || !m->hw_lm->ops.collect_misr || !m->hw_lm->ops.setup_misr)
> +			continue;

No need to check for collect_misr here, it is not used.

> +
> +		/* Calculate MISR over 1 frame */
> +		m->hw_lm->ops.setup_misr(m->hw_lm, true, 1);
> +	}
> +
> +
> +cleanup:
> +	if (commit)
> +		drm_crtc_commit_put(commit);
> +	drm_modeset_unlock(&crtc->mutex);
> +
> +	return ret;
> +}
> +
>   static u32 dpu_crtc_get_vblank_counter(struct drm_crtc *crtc)
>   {
>   	struct drm_encoder *encoder;
> @@ -83,6 +198,52 @@ static u32 dpu_crtc_get_vblank_counter(struct drm_crtc *crtc)
>   	return dpu_encoder_get_frame_count(encoder);
>   }
>   
> +
> +static void dpu_crtc_get_crc(struct drm_crtc *crtc)
> +{
> +	struct dpu_crtc *dpu_crtc;
> +	struct dpu_crtc_state *crtc_state;
> +	struct dpu_crtc_mixer *m;
> +	u32 *crcs;
> +
> +	int i = 0;
> +	int rc = 0;
> +
> +	if (!crtc) {
> +		DPU_ERROR("Invalid crtc\n");
> +		return;
> +	}
> +
> +	crtc_state = to_dpu_crtc_state(crtc->state);
> +	dpu_crtc = to_dpu_crtc(crtc);
> +	crcs = kcalloc(crtc_state->num_mixers, sizeof(*crcs), GFP_KERNEL);

This would be constantly leaking the memory. You missed kfree in all 
return paths (both error and non-error). Since you are limited by the 
max amount of mixers in the crtc (which is 2 currently and can be 4 at 
max IIRC), I'd use the on-stack array rather than calling into memory 
allocator.

> +
> +	/* Skip first 2 frames in case of "uncooked" CRCs */
> +	if (crtc_state->skip_count < 2) {
> +		crtc_state->skip_count++;

You see, missing kfree() here.

> +		return;
> +	}
> +
> +	for (i = 0; i < crtc_state->num_mixers; ++i) {
> +
> +		m = &crtc_state->mixers[i];
> +
> +		if (!m->hw_lm || !m->hw_lm->ops.collect_misr
> +			|| !m->hw_lm->ops.setup_misr)

And here we do not use setup_misr, do we?

> +			continue;
> +
> +		rc = m->hw_lm->ops.collect_misr(m->hw_lm, &crcs[i]);
> +
> +		if (rc) {
> +			DRM_DEBUG_DRIVER("MISR read failed\n");

And here

> +			return;
> +		}
> +	}
> +
> +	drm_crtc_add_crc_entry(crtc, true,
> +			drm_crtc_accurate_vblank_count(crtc), crcs);

And even here.

Also I'd propagate the erorr code here. We might not care later, but 
let's not ignore it if we can.

> +}
> +
>   static bool dpu_crtc_get_scanout_position(struct drm_crtc *crtc,
>   					   bool in_vblank_irq,
>   					   int *vpos, int *hpos,
> @@ -389,6 +550,10 @@ void dpu_crtc_vblank_callback(struct drm_crtc *crtc)
>   		dpu_crtc->vblank_cb_time = ktime_get();
>   	else
>   		dpu_crtc->vblank_cb_count++;
> +
> +	if (dpu_crtc_is_valid_crc_source(dpu_crtc->crc_source))
> +		dpu_crtc_get_crc(crtc);
> +
>   	drm_crtc_handle_vblank(crtc);
>   	trace_dpu_crtc_vblank_cb(DRMID(crtc));
>   }
> @@ -1332,6 +1497,8 @@ static const struct drm_crtc_funcs dpu_crtc_funcs = {
>   	.atomic_destroy_state = dpu_crtc_destroy_state,
>   	.late_register = dpu_crtc_late_register,
>   	.early_unregister = dpu_crtc_early_unregister,
> +	.verify_crc_source = dpu_crtc_verify_crc_source,
> +	.set_crc_source = dpu_crtc_set_crc_source,
>   	.enable_vblank  = msm_crtc_enable_vblank,
>   	.disable_vblank = msm_crtc_disable_vblank,
>   	.get_vblank_timestamp = drm_crtc_vblank_helper_get_vblank_timestamp,
> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.h b/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.h
> index cec3474340e8..e9940f1d5d15 100644
> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.h
> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.h
> @@ -1,6 +1,6 @@
>   /* SPDX-License-Identifier: GPL-2.0-only */
>   /*
> - * Copyright (c) 2015-2018 The Linux Foundation. All rights reserved.
> + * Copyright (c) 2015-2021 The Linux Foundation. All rights reserved.
>    * Copyright (C) 2013 Red Hat
>    * Author: Rob Clark <robdclark@gmail.com>
>    */
> @@ -69,6 +69,19 @@ struct dpu_crtc_smmu_state_data {
>   	uint32_t transition_error;
>   };
>   
> +/**
> + * 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_INVALID: Invalid source
> + */
> +enum dpu_crtc_crc_source {
> +	DPU_CRTC_CRC_SOURCE_NONE = 0,
> +	DPU_CRTC_CRC_SOURCE_LAYER_MIXER,
> +	DPU_CRTC_CRC_SOURCE_MAX,
> +	DPU_CRTC_CRC_SOURCE_INVALID = -1
> +};
> +
>   /**
>    * struct dpu_crtc_mixer: stores the map for each virtual pipeline in the CRTC
>    * @hw_lm:	LM HW Driver context
> @@ -139,6 +152,7 @@ struct dpu_crtc_frame_event {
>    * @event_lock    : Spinlock around event handling code
>    * @phandle: Pointer to power handler
>    * @cur_perf      : current performance committed to clock/bandwidth driver
> + * @crc_source    : CRC source
>    */
>   struct dpu_crtc {
>   	struct drm_crtc base;
> @@ -171,8 +185,8 @@ struct dpu_crtc {
>   	spinlock_t event_lock;
>   
>   	struct dpu_core_perf_params cur_perf;
> -

Unrelated

>   	struct dpu_crtc_smmu_state_data smmu_state;
> +	enum dpu_crtc_crc_source crc_source;

I think it would find a better place at the dpu_crtc_state, wouldn't it?

>   };
>   
>   #define to_dpu_crtc(x) container_of(x, struct dpu_crtc, base)
> @@ -210,6 +224,8 @@ struct dpu_crtc_state {
>   
>   	u32 num_ctls;
>   	struct dpu_hw_ctl *hw_ctls[CRTC_DUAL_MIXERS];
> +
> +	int skip_count;

What are we skipping? Could you please rename it so that usage is clearer.

>   };
>   
>   #define to_dpu_crtc_state(x) \
> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_lm.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_lm.c
> index cb6bb7a22c15..679b3728e891 100644
> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_lm.c
> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_lm.c
> @@ -1,5 +1,6 @@
>   // SPDX-License-Identifier: GPL-2.0-only
> -/* Copyright (c) 2015-2018, The Linux Foundation. All rights reserved.
> +/*
> + * Copyright (c) 2015-2021, The Linux Foundation. All rights reserved.
>    */
>   
>   #include "dpu_kms.h"
> @@ -24,6 +25,9 @@
>   #define LM_BLEND0_FG_ALPHA               0x04
>   #define LM_BLEND0_BG_ALPHA               0x08
>   
> +#define LM_MISR_CTRL                     0x310
> +#define LM_MISR_SIGNATURE                0x314
> +
>   static const struct dpu_lm_cfg *_lm_offset(enum dpu_lm mixer,
>   		const struct dpu_mdss_cfg *m,
>   		void __iomem *addr,
> @@ -96,6 +100,44 @@ static void dpu_hw_lm_setup_border_color(struct dpu_hw_mixer *ctx,
>   	}
>   }
>   
> +static void dpu_hw_lm_setup_misr(struct dpu_hw_mixer *ctx, bool enable, u32 frame_count)
> +{
> +	struct dpu_hw_blk_reg_map *c = &ctx->hw;
> +	u32 config = 0;
> +
> +	DPU_REG_WRITE(c, LM_MISR_CTRL, MISR_CTRL_STATUS_CLEAR);
> +
> +	/* Clear MISR data */
> +	wmb();

Do we need wmb here? Maybe it would be more logical to setup 
LM_MISR_CTRL and clear the status afterwards?

> +
> +	if (enable)
> +		config = (frame_count & MISR_FRAME_COUNT_MASK) |
> +			MISR_CTRL_ENABLE | INTF_MISR_CTRL_FREE_RUN_MASK;
> +
> +	DPU_REG_WRITE(c, LM_MISR_CTRL, config);

I think the following might be better:

if (enable)
    DPU_REG_WRITE(c, LM_MISR_CTRL, config);
else
    DPU_REG_WRITE(c, LM_MISR_CTRL, 0);

> +}
> +
> +static int dpu_hw_lm_collect_misr(struct dpu_hw_mixer *ctx, u32 *misr_value)
> +{
> +	struct dpu_hw_blk_reg_map *c = &ctx->hw;
> +	u32 ctrl = 0;
> +
> +	if (!misr_value)
> +		return -EINVAL;
> +
> +	ctrl = DPU_REG_READ(c, LM_MISR_CTRL);
> +
> +	if (!(ctrl & MISR_CTRL_ENABLE))
> +		return -EINVAL;
> +
> +	if (!(ctrl & MISR_CTRL_STATUS))
> +		return -EINVAL;
> +
> +	*misr_value = DPU_REG_READ(c, LM_MISR_SIGNATURE);
> +
> +	return 0;
> +}
> +
>   static void dpu_hw_lm_setup_blend_config_sdm845(struct dpu_hw_mixer *ctx,
>   	u32 stage, u32 fg_alpha, u32 bg_alpha, u32 blend_op)
>   {
> @@ -158,6 +200,8 @@ static void _setup_mixer_ops(const struct dpu_mdss_cfg *m,
>   		ops->setup_blend_config = dpu_hw_lm_setup_blend_config;
>   	ops->setup_alpha_out = dpu_hw_lm_setup_color3;
>   	ops->setup_border_color = dpu_hw_lm_setup_border_color;
> +	ops->setup_misr = dpu_hw_lm_setup_misr;
> +	ops->collect_misr = dpu_hw_lm_collect_misr;
>   }
>   
>   struct dpu_hw_mixer *dpu_hw_lm_init(enum dpu_lm idx,
> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_lm.h b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_lm.h
> index 4a6b2de19ef6..d8052fb2d5da 100644
> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_lm.h
> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_lm.h
> @@ -1,5 +1,6 @@
>   /* SPDX-License-Identifier: GPL-2.0-only */
> -/* Copyright (c) 2015-2018, The Linux Foundation. All rights reserved.
> +/*
> + * Copyright (c) 2015-2021, The Linux Foundation. All rights reserved.
>    */
>   
>   #ifndef _DPU_HW_LM_H
> @@ -53,6 +54,16 @@ struct dpu_hw_lm_ops {
>   	void (*setup_border_color)(struct dpu_hw_mixer *ctx,
>   		struct dpu_mdss_color *color,
>   		u8 border_en);
> +
> +	/**
> +	 * setup_misr: Enable/disable MISR
> +	 */
> +	void (*setup_misr)(struct dpu_hw_mixer *ctx, bool enable, u32 frame_count);
> +
> +	/**
> +	 * collect_misr: Read MISR signature
> +	 */
> +	int (*collect_misr)(struct dpu_hw_mixer *ctx, u32 *misr_value);
>   };
>   
>   struct dpu_hw_mixer {
> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_util.h b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_util.h
> index ff3cffde84cd..506d4af7d018 100644
> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_util.h
> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_util.h
> @@ -1,5 +1,6 @@
>   /* SPDX-License-Identifier: GPL-2.0-only */
> -/* Copyright (c) 2015-2018, The Linux Foundation. All rights reserved.
> +/*
> + * Copyright (c) 2015-2021, The Linux Foundation. All rights reserved.
>    */
>   
>   #ifndef _DPU_HW_UTIL_H
> @@ -309,6 +310,12 @@ int dpu_reg_read(struct dpu_hw_blk_reg_map *c, u32 reg_off);
>   #define DPU_REG_WRITE(c, off, val) dpu_reg_write(c, off, val, #off)
>   #define DPU_REG_READ(c, off) dpu_reg_read(c, off)
>   
> +#define MISR_FRAME_COUNT_MASK           0xFF
> +#define MISR_CTRL_ENABLE                BIT(8)
> +#define MISR_CTRL_STATUS                BIT(9)
> +#define MISR_CTRL_STATUS_CLEAR          BIT(10)
> +#define INTF_MISR_CTRL_FREE_RUN_MASK    BIT(31)
> +

This seems totally unrelated to dpu_hw_util.h  Please move to 
dpu_hw_lm.c where they belong. And please fix the prefixes.

>   void *dpu_hw_util_get_dir(void);
>   
>   void dpu_hw_setup_scaler3(struct dpu_hw_blk_reg_map *c,
> 


-- 
With best wishes
Dmitry

Re: [PATCH] drm/msm/dpu: Add CRC support for DPU

[kernel test robot]

[-- Attachment #1: Type: text/plain, Size: 5616 bytes --]

Hi Jessica,

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on linus/master]
[also build test WARNING on v5.15-rc5 next-20211011]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]

url:    https://github.com/0day-ci/linux/commits/Jessica-Zhang/drm-msm-dpu-Add-CRC-support-for-DPU/20211012-074357
base:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 64570fbc14f8d7cb3fe3995f20e26bc25ce4b2cc
config: arm-qcom_defconfig (attached as .config)
compiler: arm-linux-gnueabi-gcc (GCC) 11.2.0
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # https://github.com/0day-ci/linux/commit/5260fd396b774196018bdb110b213ce9abde8853
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Jessica-Zhang/drm-msm-dpu-Add-CRC-support-for-DPU/20211012-074357
        git checkout 5260fd396b774196018bdb110b213ce9abde8853
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.2.0 make.cross ARCH=arm 

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All warnings (new ones prefixed by >>):

>> drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c:89:5: warning: no previous prototype for 'dpu_crtc_verify_crc_source' [-Wmissing-prototypes]
      89 | int dpu_crtc_verify_crc_source(struct drm_crtc *crtc, const char *src_name, size_t *values_cnt)
         |     ^~~~~~~~~~~~~~~~~~~~~~~~~~
>> drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c:105:5: warning: no previous prototype for 'dpu_crtc_set_crc_source' [-Wmissing-prototypes]
     105 | int dpu_crtc_set_crc_source(struct drm_crtc *crtc, const char *src_name)
         |     ^~~~~~~~~~~~~~~~~~~~~~~
   drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c: In function 'dpu_crtc_get_crc':
   drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c:204:26: warning: variable 'dpu_crtc' set but not used [-Wunused-but-set-variable]
     204 |         struct dpu_crtc *dpu_crtc;
         |                          ^~~~~~~~


vim +/dpu_crtc_verify_crc_source +89 drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c

    88	
  > 89	int dpu_crtc_verify_crc_source(struct drm_crtc *crtc, const char *src_name, size_t *values_cnt)
    90	{
    91		enum dpu_crtc_crc_source source = dpu_crtc_parse_crc_source(src_name);
    92		struct dpu_crtc_state *crtc_state = to_dpu_crtc_state(crtc->state);
    93	
    94		if (source < 0) {
    95			DRM_DEBUG_DRIVER("Invalid source %s for CRTC%d\n", src_name, crtc->index);
    96			return -EINVAL;
    97		}
    98	
    99		if (source == DPU_CRTC_CRC_SOURCE_LAYER_MIXER)
   100			*values_cnt = crtc_state->num_mixers;
   101	
   102		return 0;
   103	}
   104	
 > 105	int dpu_crtc_set_crc_source(struct drm_crtc *crtc, const char *src_name)
   106	{
   107		enum dpu_crtc_crc_source source = dpu_crtc_parse_crc_source(src_name);
   108		enum dpu_crtc_crc_source current_source;
   109		struct drm_crtc_commit *commit;
   110		struct dpu_crtc_state *crtc_state;
   111		struct drm_device *drm_dev = crtc->dev;
   112		struct dpu_crtc *dpu_crtc = to_dpu_crtc(crtc);
   113		struct dpu_crtc_mixer *m;
   114	
   115		bool was_enabled;
   116		bool enable = false;
   117		int i, ret = 0;
   118	
   119		if (source < 0) {
   120			DRM_DEBUG_DRIVER("Invalid CRC source %s for CRTC%d\n", src_name, crtc->index);
   121			return -EINVAL;
   122		}
   123	
   124		ret = drm_modeset_lock(&crtc->mutex, NULL);
   125	
   126		if (ret)
   127			return ret;
   128	
   129		/* Wait for any pending commits to finish */
   130		spin_lock(&crtc->commit_lock);
   131		commit = list_first_entry_or_null(&crtc->commit_list, struct drm_crtc_commit, commit_entry);
   132	
   133		if (commit)
   134			drm_crtc_commit_get(commit);
   135		spin_unlock(&crtc->commit_lock);
   136	
   137		if (commit) {
   138			ret = wait_for_completion_interruptible_timeout(&commit->hw_done, 10 * HZ);
   139	
   140			if (ret)
   141				goto cleanup;
   142		}
   143	
   144		enable = dpu_crtc_is_valid_crc_source(source);
   145		crtc_state = to_dpu_crtc_state(crtc->state);
   146	
   147		spin_lock_irq(&drm_dev->event_lock);
   148		current_source = dpu_crtc->crc_source;
   149		spin_unlock_irq(&drm_dev->event_lock);
   150	
   151		was_enabled = !(current_source == DPU_CRTC_CRC_SOURCE_NONE);
   152	
   153		if (!was_enabled && enable) {
   154			ret = drm_crtc_vblank_get(crtc);
   155	
   156			if (ret)
   157				goto cleanup;
   158	
   159		} else if (was_enabled && !enable) {
   160			drm_crtc_vblank_put(crtc);
   161		}
   162	
   163		spin_lock_irq(&drm_dev->event_lock);
   164		dpu_crtc->crc_source = source;
   165		spin_unlock_irq(&drm_dev->event_lock);
   166	
   167		crtc_state->skip_count = 0;
   168	
   169		for (i = 0; i < crtc_state->num_mixers; ++i) {
   170			m = &crtc_state->mixers[i];
   171	
   172			if (!m->hw_lm || !m->hw_lm->ops.collect_misr || !m->hw_lm->ops.setup_misr)
   173				continue;
   174	
   175			/* Calculate MISR over 1 frame */
   176			m->hw_lm->ops.setup_misr(m->hw_lm, true, 1);
   177		}
   178	
   179	
   180	cleanup:
   181		if (commit)
   182			drm_crtc_commit_put(commit);
   183		drm_modeset_unlock(&crtc->mutex);
   184	
   185		return ret;
   186	}
   187	

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org

[-- Attachment #2: .config.gz --]
[-- Type: application/gzip, Size: 39887 bytes --]

Re: [PATCH] drm/msm/dpu: Add CRC support for DPU

[Jessica Zhang]

On 10/11/2021 7:01 PM, Dmitry Baryshkov wrote:
> On 12/10/2021 02:41, Jessica Zhang wrote:
>> Add CRC support to DPU, which is currently not supported by
>> this driver. Only supports CRC for CRTC for now, but will extend support
>> to other blocks later on.
>>
>> Tested on Qualcomm RB3 (debian, sdm845)
>>
>> Signed-off-by: Jessica Zhang <jesszhan@codeaurora.org>
>> ---
>>   drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c    | 169 +++++++++++++++++++-
>>   drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.h    |  20 ++-
>>   drivers/gpu/drm/msm/disp/dpu1/dpu_hw_lm.c   |  46 +++++-
>>   drivers/gpu/drm/msm/disp/dpu1/dpu_hw_lm.h   |  13 +-
>>   drivers/gpu/drm/msm/disp/dpu1/dpu_hw_util.h |   9 +-
>>   5 files changed, 251 insertions(+), 6 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c 
>> b/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c
>> index 768012243b44..6ebf989c4e67 100644
>> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c
>> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c
>> @@ -1,6 +1,6 @@
>>   // SPDX-License-Identifier: GPL-2.0-only
>>   /*
>> - * Copyright (c) 2014-2018 The Linux Foundation. All rights reserved.
>> + * Copyright (c) 2014-2021 The Linux Foundation. All rights reserved.
>>    * Copyright (C) 2013 Red Hat
>>    * Author: Rob Clark <robdclark@gmail.com>
>>    */
>> @@ -70,6 +70,121 @@ static struct drm_encoder 
>> *get_encoder_from_crtc(struct drm_crtc *crtc)
>>       return NULL;
>>   }
>>   +static enum dpu_crtc_crc_source dpu_crtc_parse_crc_source(const 
>> char *src_name)
>> +{
>> +    if (!src_name || !strcmp(src_name, "none"))
>> +        return DPU_CRTC_CRC_SOURCE_NONE;
>
> Newlines after || please. this would improve readability.
Noted.
>
>> +    if (!strcmp(src_name, "auto") || !strcmp(src_name, "lm"))
>> +        return DPU_CRTC_CRC_SOURCE_LAYER_MIXER;
>> +
>> +    return DPU_CRTC_CRC_SOURCE_INVALID;
>> +}
>> +
>> +static bool dpu_crtc_is_valid_crc_source(enum dpu_crtc_crc_source 
>> source)
>> +{
>> +    return (source > DPU_CRTC_CRC_SOURCE_NONE &&
>> +        source < DPU_CRTC_CRC_SOURCE_MAX);
>> +}
>> +
>> +int dpu_crtc_verify_crc_source(struct drm_crtc *crtc, const char 
>> *src_name, size_t *values_cnt)
>> +{
>> +    enum dpu_crtc_crc_source source = 
>> dpu_crtc_parse_crc_source(src_name);
>> +    struct dpu_crtc_state *crtc_state = to_dpu_crtc_state(crtc->state);
>> +
>> +    if (source < 0) {
>
> Just use dpu_crtc_is_valid_crtc_source() here.

dpu_crtc_is_valid_crc_source() is not exactly the same as checking if 
the source *name* is valid, as "none" is a valid source name (e.g. would 
pass the `source < 0` check), but 
dpu_crtc_is_valid_crc_source(DPU_CRTC_CRC_SOURCE_NONE) would return 
false as DPU_CRTC_CRC_SOURCE_NONE represents when the CRC source is set 
to nothing. The general purpose of dpu_crc_is_valid_crtc_source() is to 
check that the source specified is able to return a CRC value, so a 
source set to "none" would return false, even though "none" is a 
technically valid source name.

Seems like the root issue is that the name 
"dpu_crtc_is_valid_crc_source" is misleading and it would be better to 
rename the helper method to something clearer. Or replace the 
dpu_crtc_is_valid_crc_source() checks with a check against 
DPU_CRTC_CRC_SOURCE_NONE instead.

>
>> +        DRM_DEBUG_DRIVER("Invalid source %s for CRTC%d\n", src_name, 
>> crtc->index);
>> +        return -EINVAL;
>> +    }
>> +
>> +    if (source == DPU_CRTC_CRC_SOURCE_LAYER_MIXER)
>> +        *values_cnt = crtc_state->num_mixers;
>> +
>> +    return 0;
>> +}
>> +
>> +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);
>> +    enum dpu_crtc_crc_source current_source;
>> +    struct drm_crtc_commit *commit;
>> +    struct dpu_crtc_state *crtc_state;
>> +    struct drm_device *drm_dev = crtc->dev;
>> +    struct dpu_crtc *dpu_crtc = to_dpu_crtc(crtc);
>> +    struct dpu_crtc_mixer *m;
>> +
>> +    bool was_enabled;
>> +    bool enable = false;
>> +    int i, ret = 0;
>> +
>> +    if (source < 0) {
>> +        DRM_DEBUG_DRIVER("Invalid CRC source %s for CRTC%d\n", 
>> src_name, crtc->index);
>> +        return -EINVAL;
>> +    }
>> +
>> +    ret = drm_modeset_lock(&crtc->mutex, NULL);
>> +
>> +    if (ret)
>> +        return ret;
>> +
>> +    /* Wait for any pending commits to finish */
>> +    spin_lock(&crtc->commit_lock);
>> +    commit = list_first_entry_or_null(&crtc->commit_list, struct 
>> drm_crtc_commit, commit_entry);
>> +
>> +    if (commit)
>> +        drm_crtc_commit_get(commit);
>> +    spin_unlock(&crtc->commit_lock);
>> +
>> +    if (commit) {
>> +        ret = 
>> wait_for_completion_interruptible_timeout(&commit->hw_done, 10 * HZ);
>> +
>> +        if (ret)
>> +            goto cleanup;
>> +    }
>
> AMD drivers waits for the commit to finish, because it's commit tail 
> can modify CRC-related registers. It unique, no other drivers seem to 
> do this kind of wait. Why do we need to do it? And if we really need, 
> I'd prefer to have this code in some kind of DRM helper function.
>
Makes sense. I wanted to include it to be safe, but as far as I know 
nothing that happens during a commit will affect reading the CRC for 
this driver. I've also tested without the wait for commit and it doesn't 
seem to affect the CRC read, so I'll remove it.
>
>> +    enable = dpu_crtc_is_valid_crc_source(source);
>> +    crtc_state = to_dpu_crtc_state(crtc->state);
>> +
>> +    spin_lock_irq(&drm_dev->event_lock);
>> +    current_source = dpu_crtc->crc_source;
>> +    spin_unlock_irq(&drm_dev->event_lock);
>> +
>> +    was_enabled = !(current_source == DPU_CRTC_CRC_SOURCE_NONE);
>
> current_source != DPU_CRTC_CRC_SOURCE_NONE would be easier.
>
Noted.
>> +
>> +    if (!was_enabled && enable) {
>> +        ret = drm_crtc_vblank_get(crtc);
>> +
>> +        if (ret)
>> +            goto cleanup;
>> +
>> +    } else if (was_enabled && !enable) {
>> +        drm_crtc_vblank_put(crtc);
>> +    }
>> +
>> +    spin_lock_irq(&drm_dev->event_lock);
>> +    dpu_crtc->crc_source = source;
>> +    spin_unlock_irq(&drm_dev->event_lock);
>> +
>> +    crtc_state->skip_count = 0;
>> +
>> +    for (i = 0; i < crtc_state->num_mixers; ++i) {
>> +        m = &crtc_state->mixers[i];
>> +
>> +        if (!m->hw_lm || !m->hw_lm->ops.collect_misr || 
>> !m->hw_lm->ops.setup_misr)
>> +            continue;
>
> No need to check for collect_misr here, it is not used.
>
Noted.
>> +
>> +        /* Calculate MISR over 1 frame */
>> +        m->hw_lm->ops.setup_misr(m->hw_lm, true, 1);
>> +    }
>> +
>> +
>> +cleanup:
>> +    if (commit)
>> +        drm_crtc_commit_put(commit);
>> +    drm_modeset_unlock(&crtc->mutex);
>> +
>> +    return ret;
>> +}
>> +
>>   static u32 dpu_crtc_get_vblank_counter(struct drm_crtc *crtc)
>>   {
>>       struct drm_encoder *encoder;
>> @@ -83,6 +198,52 @@ static u32 dpu_crtc_get_vblank_counter(struct 
>> drm_crtc *crtc)
>>       return dpu_encoder_get_frame_count(encoder);
>>   }
>>   +
>> +static void dpu_crtc_get_crc(struct drm_crtc *crtc)
>> +{
>> +    struct dpu_crtc *dpu_crtc;
>> +    struct dpu_crtc_state *crtc_state;
>> +    struct dpu_crtc_mixer *m;
>> +    u32 *crcs;
>> +
>> +    int i = 0;
>> +    int rc = 0;
>> +
>> +    if (!crtc) {
>> +        DPU_ERROR("Invalid crtc\n");
>> +        return;
>> +    }
>> +
>> +    crtc_state = to_dpu_crtc_state(crtc->state);
>> +    dpu_crtc = to_dpu_crtc(crtc);
>> +    crcs = kcalloc(crtc_state->num_mixers, sizeof(*crcs), GFP_KERNEL);
>
> This would be constantly leaking the memory. You missed kfree in all 
> return paths (both error and non-error). Since you are limited by the 
> max amount of mixers in the crtc (which is 2 currently and can be 4 at 
> max IIRC), I'd use the on-stack array rather than calling into memory 
> allocator.
>
Noted.
>> +
>> +    /* Skip first 2 frames in case of "uncooked" CRCs */
>> +    if (crtc_state->skip_count < 2) {
>> +        crtc_state->skip_count++;
>
> You see, missing kfree() here.
>
Noted.
>> +        return;
>> +    }
>> +
>> +    for (i = 0; i < crtc_state->num_mixers; ++i) {
>> +
>> +        m = &crtc_state->mixers[i];
>> +
>> +        if (!m->hw_lm || !m->hw_lm->ops.collect_misr
>> +            || !m->hw_lm->ops.setup_misr)
>
> And here we do not use setup_misr, do we?
>
Noted, removed setup_misr check.
>> +            continue;
>> +
>> +        rc = m->hw_lm->ops.collect_misr(m->hw_lm, &crcs[i]);
>> +
>> +        if (rc) {
>> +            DRM_DEBUG_DRIVER("MISR read failed\n");
>
> And here
>
>> +            return;
>> +        }
>> +    }
>> +
>> +    drm_crtc_add_crc_entry(crtc, true,
>> +            drm_crtc_accurate_vblank_count(crtc), crcs);
>
> And even here.
>
> Also I'd propagate the erorr code here. We might not care later, but 
> let's not ignore it if we can.
>
Noted.
>> +}
>> +
>>   static bool dpu_crtc_get_scanout_position(struct drm_crtc *crtc,
>>                          bool in_vblank_irq,
>>                          int *vpos, int *hpos,
>> @@ -389,6 +550,10 @@ void dpu_crtc_vblank_callback(struct drm_crtc 
>> *crtc)
>>           dpu_crtc->vblank_cb_time = ktime_get();
>>       else
>>           dpu_crtc->vblank_cb_count++;
>> +
>> +    if (dpu_crtc_is_valid_crc_source(dpu_crtc->crc_source))
>> +        dpu_crtc_get_crc(crtc);
>> +
>>       drm_crtc_handle_vblank(crtc);
>>       trace_dpu_crtc_vblank_cb(DRMID(crtc));
>>   }
>> @@ -1332,6 +1497,8 @@ static const struct drm_crtc_funcs 
>> dpu_crtc_funcs = {
>>       .atomic_destroy_state = dpu_crtc_destroy_state,
>>       .late_register = dpu_crtc_late_register,
>>       .early_unregister = dpu_crtc_early_unregister,
>> +    .verify_crc_source = dpu_crtc_verify_crc_source,
>> +    .set_crc_source = dpu_crtc_set_crc_source,
>>       .enable_vblank  = msm_crtc_enable_vblank,
>>       .disable_vblank = msm_crtc_disable_vblank,
>>       .get_vblank_timestamp = 
>> drm_crtc_vblank_helper_get_vblank_timestamp,
>> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.h 
>> b/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.h
>> index cec3474340e8..e9940f1d5d15 100644
>> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.h
>> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.h
>> @@ -1,6 +1,6 @@
>>   /* SPDX-License-Identifier: GPL-2.0-only */
>>   /*
>> - * Copyright (c) 2015-2018 The Linux Foundation. All rights reserved.
>> + * Copyright (c) 2015-2021 The Linux Foundation. All rights reserved.
>>    * Copyright (C) 2013 Red Hat
>>    * Author: Rob Clark <robdclark@gmail.com>
>>    */
>> @@ -69,6 +69,19 @@ struct dpu_crtc_smmu_state_data {
>>       uint32_t transition_error;
>>   };
>>   +/**
>> + * 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_INVALID: Invalid source
>> + */
>> +enum dpu_crtc_crc_source {
>> +    DPU_CRTC_CRC_SOURCE_NONE = 0,
>> +    DPU_CRTC_CRC_SOURCE_LAYER_MIXER,
>> +    DPU_CRTC_CRC_SOURCE_MAX,
>> +    DPU_CRTC_CRC_SOURCE_INVALID = -1
>> +};
>> +
>>   /**
>>    * struct dpu_crtc_mixer: stores the map for each virtual pipeline 
>> in the CRTC
>>    * @hw_lm:    LM HW Driver context
>> @@ -139,6 +152,7 @@ struct dpu_crtc_frame_event {
>>    * @event_lock    : Spinlock around event handling code
>>    * @phandle: Pointer to power handler
>>    * @cur_perf      : current performance committed to 
>> clock/bandwidth driver
>> + * @crc_source    : CRC source
>>    */
>>   struct dpu_crtc {
>>       struct drm_crtc base;
>> @@ -171,8 +185,8 @@ struct dpu_crtc {
>>       spinlock_t event_lock;
>>         struct dpu_core_perf_params cur_perf;
>> -
>
> Unrelated
>
Noted.

>>       struct dpu_crtc_smmu_state_data smmu_state;
>> +    enum dpu_crtc_crc_source crc_source;
>
> I think it would find a better place at the dpu_crtc_state, wouldn't it?
>
Makes sense.
>>   };
>>     #define to_dpu_crtc(x) container_of(x, struct dpu_crtc, base)
>> @@ -210,6 +224,8 @@ struct dpu_crtc_state {
>>         u32 num_ctls;
>>       struct dpu_hw_ctl *hw_ctls[CRTC_DUAL_MIXERS];
>> +
>> +    int skip_count;
>
> What are we skipping? Could you please rename it so that usage is 
> clearer.
>
Noted.
>>   };
>>     #define to_dpu_crtc_state(x) \
>> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_lm.c 
>> b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_lm.c
>> index cb6bb7a22c15..679b3728e891 100644
>> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_lm.c
>> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_lm.c
>> @@ -1,5 +1,6 @@
>>   // SPDX-License-Identifier: GPL-2.0-only
>> -/* Copyright (c) 2015-2018, The Linux Foundation. All rights reserved.
>> +/*
>> + * Copyright (c) 2015-2021, The Linux Foundation. All rights reserved.
>>    */
>>     #include "dpu_kms.h"
>> @@ -24,6 +25,9 @@
>>   #define LM_BLEND0_FG_ALPHA               0x04
>>   #define LM_BLEND0_BG_ALPHA               0x08
>>   +#define LM_MISR_CTRL                     0x310
>> +#define LM_MISR_SIGNATURE                0x314
>> +
>>   static const struct dpu_lm_cfg *_lm_offset(enum dpu_lm mixer,
>>           const struct dpu_mdss_cfg *m,
>>           void __iomem *addr,
>> @@ -96,6 +100,44 @@ static void dpu_hw_lm_setup_border_color(struct 
>> dpu_hw_mixer *ctx,
>>       }
>>   }
>>   +static void dpu_hw_lm_setup_misr(struct dpu_hw_mixer *ctx, bool 
>> enable, u32 frame_count)
>> +{
>> +    struct dpu_hw_blk_reg_map *c = &ctx->hw;
>> +    u32 config = 0;
>> +
>> +    DPU_REG_WRITE(c, LM_MISR_CTRL, MISR_CTRL_STATUS_CLEAR);
>> +
>> +    /* Clear MISR data */
>> +    wmb();
>
> Do we need wmb here? Maybe it would be more logical to setup 
> LM_MISR_CTRL and clear the status afterwards?
>
We want to guarantee that MISR_SIGNATURE is cleared before it's read in 
case MISR_SIGNATURE is read before a new value is calculated.
>> +
>> +    if (enable)
>> +        config = (frame_count & MISR_FRAME_COUNT_MASK) |
>> +            MISR_CTRL_ENABLE | INTF_MISR_CTRL_FREE_RUN_MASK;
>> +
>> +    DPU_REG_WRITE(c, LM_MISR_CTRL, config);
>
> I think the following might be better:
>
> if (enable)
>    DPU_REG_WRITE(c, LM_MISR_CTRL, config);
> else
>    DPU_REG_WRITE(c, LM_MISR_CTRL, 0);
>
Hmm... agreed. I can see how this may increase readability.
>> +}
>> +
>> +static int dpu_hw_lm_collect_misr(struct dpu_hw_mixer *ctx, u32 
>> *misr_value)
>> +{
>> +    struct dpu_hw_blk_reg_map *c = &ctx->hw;
>> +    u32 ctrl = 0;
>> +
>> +    if (!misr_value)
>> +        return -EINVAL;
>> +
>> +    ctrl = DPU_REG_READ(c, LM_MISR_CTRL);
>> +
>> +    if (!(ctrl & MISR_CTRL_ENABLE))
>> +        return -EINVAL;
>> +
>> +    if (!(ctrl & MISR_CTRL_STATUS))
>> +        return -EINVAL;
>> +
>> +    *misr_value = DPU_REG_READ(c, LM_MISR_SIGNATURE);
>> +
>> +    return 0;
>> +}
>> +
>>   static void dpu_hw_lm_setup_blend_config_sdm845(struct dpu_hw_mixer 
>> *ctx,
>>       u32 stage, u32 fg_alpha, u32 bg_alpha, u32 blend_op)
>>   {
>> @@ -158,6 +200,8 @@ static void _setup_mixer_ops(const struct 
>> dpu_mdss_cfg *m,
>>           ops->setup_blend_config = dpu_hw_lm_setup_blend_config;
>>       ops->setup_alpha_out = dpu_hw_lm_setup_color3;
>>       ops->setup_border_color = dpu_hw_lm_setup_border_color;
>> +    ops->setup_misr = dpu_hw_lm_setup_misr;
>> +    ops->collect_misr = dpu_hw_lm_collect_misr;
>>   }
>>     struct dpu_hw_mixer *dpu_hw_lm_init(enum dpu_lm idx,
>> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_lm.h 
>> b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_lm.h
>> index 4a6b2de19ef6..d8052fb2d5da 100644
>> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_lm.h
>> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_lm.h
>> @@ -1,5 +1,6 @@
>>   /* SPDX-License-Identifier: GPL-2.0-only */
>> -/* Copyright (c) 2015-2018, The Linux Foundation. All rights reserved.
>> +/*
>> + * Copyright (c) 2015-2021, The Linux Foundation. All rights reserved.
>>    */
>>     #ifndef _DPU_HW_LM_H
>> @@ -53,6 +54,16 @@ struct dpu_hw_lm_ops {
>>       void (*setup_border_color)(struct dpu_hw_mixer *ctx,
>>           struct dpu_mdss_color *color,
>>           u8 border_en);
>> +
>> +    /**
>> +     * setup_misr: Enable/disable MISR
>> +     */
>> +    void (*setup_misr)(struct dpu_hw_mixer *ctx, bool enable, u32 
>> frame_count);
>> +
>> +    /**
>> +     * collect_misr: Read MISR signature
>> +     */
>> +    int (*collect_misr)(struct dpu_hw_mixer *ctx, u32 *misr_value);
>>   };
>>     struct dpu_hw_mixer {
>> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_util.h 
>> b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_util.h
>> index ff3cffde84cd..506d4af7d018 100644
>> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_util.h
>> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_util.h
>> @@ -1,5 +1,6 @@
>>   /* SPDX-License-Identifier: GPL-2.0-only */
>> -/* Copyright (c) 2015-2018, The Linux Foundation. All rights reserved.
>> +/*
>> + * Copyright (c) 2015-2021, The Linux Foundation. All rights reserved.
>>    */
>>     #ifndef _DPU_HW_UTIL_H
>> @@ -309,6 +310,12 @@ int dpu_reg_read(struct dpu_hw_blk_reg_map *c, 
>> u32 reg_off);
>>   #define DPU_REG_WRITE(c, off, val) dpu_reg_write(c, off, val, #off)
>>   #define DPU_REG_READ(c, off) dpu_reg_read(c, off)
>>   +#define MISR_FRAME_COUNT_MASK           0xFF
>> +#define MISR_CTRL_ENABLE                BIT(8)
>> +#define MISR_CTRL_STATUS                BIT(9)
>> +#define MISR_CTRL_STATUS_CLEAR          BIT(10)
>> +#define INTF_MISR_CTRL_FREE_RUN_MASK    BIT(31)
>> +
>
> This seems totally unrelated to dpu_hw_util.h  Please move to 
> dpu_hw_lm.c where they belong. And please fix the prefixes.
>
Noted.
>>   void *dpu_hw_util_get_dir(void);
>>     void dpu_hw_setup_scaler3(struct dpu_hw_blk_reg_map *c,
>>
>
>
Thanks for the feedback!


Best,

Jessica Zhang