[PATCH v5 0/4] drm/dp: Implement CRC debugfs API

[PATCH v5 0/4] drm/dp: Implement CRC debugfs API

[Tomeu Vizoso]

Hi,

this series builds up on the API for exposing captured CRCs through
debugfs.

It adds new DP helpers for starting and stopping CRC capture and gets
the Rockchip driver to use it.

Also had to add a connector backpointer to the drm_dp_aux struct so we could
wait for the right vblank and store the CRCs afterwards, I will be glad
to hear about better alternatives.

With these patches, tests in IGT such as kms_pipe_crc_basic and
kms_plane do pass on RK3288.

In this v5, "drm/dp: add helpers for capture of frame CRCs" has gone
back to the more explicit way of just retrying once.

Also, I have left the connector back pointer in the AUX structure, as on
IRC nor danvet nor me could find a good reason to change it.

Thanks,

Tomeu


Tomeu Vizoso (4):
  drm/bridge: analogix_dp: set connector to drm_dp_aux
  drm/dp: add helpers for capture of frame CRCs
  drm/bridge: analogix_dp: add helpers for capture of frame CRCs
  drm/rockchip: Implement CRC debugfs API

 drivers/gpu/drm/bridge/analogix/analogix_dp_core.c |  34 ++++--
 drivers/gpu/drm/drm_dp_helper.c                    | 124 +++++++++++++++++++++
 drivers/gpu/drm/rockchip/rockchip_drm_vop.c        |  42 +++++++
 include/drm/bridge/analogix_dp.h                   |   3 +
 include/drm/drm_dp_helper.h                        |   7 ++
 5 files changed, 202 insertions(+), 8 deletions(-)

-- 
2.9.3

[PATCH v5 1/4] drm/bridge: analogix_dp: set connector to drm_dp_aux

[Tomeu Vizoso]

Set the backpointer so that the DP helpers are able to access the
connector that the drm_dp_aux is associated with.

Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>
---

 drivers/gpu/drm/bridge/analogix/analogix_dp_core.c | 18 ++++++++++--------
 1 file changed, 10 insertions(+), 8 deletions(-)

diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
index e7cd1056ff2d..44c2b74bf771 100644
--- a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
+++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
@@ -1403,26 +1403,28 @@ int analogix_dp_bind(struct device *dev, struct drm_device *drm_dev,
 	dp->drm_dev = drm_dev;
 	dp->encoder = dp->plat_data->encoder;
 
+	ret = analogix_dp_create_bridge(drm_dev, dp);
+	if (ret) {
+		DRM_ERROR("failed to create bridge (%d)\n", ret);
+		goto err_encoder_cleanup;
+	}
+
 	dp->aux.name = "DP-AUX";
 	dp->aux.transfer = analogix_dpaux_transfer;
 	dp->aux.dev = &pdev->dev;
+	dp->aux.connector = &dp->connector;
 
 	ret = drm_dp_aux_register(&dp->aux);
 	if (ret)
-		goto err_disable_pm_runtime;
-
-	ret = analogix_dp_create_bridge(drm_dev, dp);
-	if (ret) {
-		DRM_ERROR("failed to create bridge (%d)\n", ret);
-		drm_encoder_cleanup(dp->encoder);
-		goto err_disable_pm_runtime;
-	}
+		goto err_encoder_cleanup;
 
 	phy_power_off(dp->phy);
 	pm_runtime_put(dev);
 
 	return 0;
 
+err_encoder_cleanup:
+	drm_encoder_cleanup(dp->encoder);
 err_disable_pm_runtime:
 
 	phy_power_off(dp->phy);
-- 
2.9.3

[PATCH v5 2/4] drm/dp: add helpers for capture of frame CRCs

[Tomeu Vizoso]

Adds helpers for starting and stopping capture of frame CRCs through the
DPCD. When capture is on, a worker waits for vblanks and retrieves the
frame CRC to put it in the queue on the CRTC that is using the
eDP connector, so it's passed to userspace.

v2: Reuse drm_crtc_wait_one_vblank
    Update locking, as drm_crtc_add_crc_entry now takes the lock

v3: Don't call wake_up_interruptible directly, that's now done in
    drm_crtc_add_crc_entry.

v4: Style fixes (Sean Paul)
    Reworked retry of CRC reads (Sean Paul)
    Flush worker after stopping CRC generationa (Sean Paul)

v5: Move back to make the retry explicitly once

Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>
---

 drivers/gpu/drm/drm_dp_helper.c | 124 ++++++++++++++++++++++++++++++++++++++++
 include/drm/drm_dp_helper.h     |   7 +++
 2 files changed, 131 insertions(+)

diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c
index 3e6fe82c6d64..6dd550c7a8bd 100644
--- a/drivers/gpu/drm/drm_dp_helper.c
+++ b/drivers/gpu/drm/drm_dp_helper.c
@@ -981,6 +981,78 @@ static const struct i2c_lock_operations drm_dp_i2c_lock_ops = {
 	.unlock_bus = unlock_bus,
 };
 
+static int drm_dp_aux_get_crc(struct drm_dp_aux *aux, u8 *crc)
+{
+	u8 buf, count;
+	int ret;
+
+	ret = drm_dp_dpcd_readb(aux, DP_TEST_SINK, &buf);
+	if (ret < 0)
+		return ret;
+
+	WARN_ON(!(buf & DP_TEST_SINK_START));
+
+	ret = drm_dp_dpcd_readb(aux, DP_TEST_SINK_MISC, &buf);
+	if (ret < 0)
+		return ret;
+
+	count = buf & DP_TEST_COUNT_MASK;
+	if (count == aux->crc_count)
+		return -EAGAIN; /* No CRC yet */
+
+	aux->crc_count = count;
+
+	/*
+	 * At DP_TEST_CRC_R_CR, there's 6 bytes containing CRC data, 2 bytes
+	 * per component (RGB or CrYCb).
+	 */
+	ret = drm_dp_dpcd_read(aux, DP_TEST_CRC_R_CR, crc, 6);
+	if (ret < 0)
+		return ret;
+
+	return 0;
+}
+
+static void drm_dp_aux_crc_work(struct work_struct *work)
+{
+	struct drm_dp_aux *aux = container_of(work, struct drm_dp_aux,
+					      crc_work);
+	struct drm_crtc *crtc;
+	u8 crc_bytes[6];
+	uint32_t crcs[3];
+	int ret;
+
+	if (WARN_ON(!aux->connector))
+		return;
+
+	crtc = aux->connector->state->crtc;
+	while (crtc->crc.opened) {
+		drm_crtc_wait_one_vblank(crtc);
+		if (!crtc->crc.opened)
+			break;
+
+		ret = drm_dp_aux_get_crc(aux, crc_bytes);
+		if (ret == -EAGAIN) {
+			usleep_range(1000, 2000);
+			ret = drm_dp_aux_get_crc(aux, crc_bytes);
+		}
+
+		if (ret == -EAGAIN) {
+			DRM_DEBUG_KMS("Get CRC failed after retrying: %d\n",
+				      ret);
+			continue;
+		} else if (ret) {
+			DRM_DEBUG_KMS("Failed to get a CRC: %d\n", ret);
+			continue;
+		}
+
+		crcs[0] = crc_bytes[0] | crc_bytes[1] << 8;
+		crcs[1] = crc_bytes[2] | crc_bytes[3] << 8;
+		crcs[2] = crc_bytes[4] | crc_bytes[5] << 8;
+		drm_crtc_add_crc_entry(crtc, false, 0, crcs);
+	}
+}
+
 /**
  * drm_dp_aux_init() - minimally initialise an aux channel
  * @aux: DisplayPort AUX channel
@@ -993,6 +1065,7 @@ static const struct i2c_lock_operations drm_dp_i2c_lock_ops = {
 void drm_dp_aux_init(struct drm_dp_aux *aux)
 {
 	mutex_init(&aux->hw_mutex);
+	INIT_WORK(&aux->crc_work, drm_dp_aux_crc_work);
 
 	aux->ddc.algo = &drm_dp_i2c_algo;
 	aux->ddc.algo_data = aux;
@@ -1081,3 +1154,54 @@ int drm_dp_psr_setup_time(const u8 psr_cap[EDP_PSR_RECEIVER_CAP_SIZE])
 EXPORT_SYMBOL(drm_dp_psr_setup_time);
 
 #undef PSR_SETUP_TIME
+
+/**
+ * drm_dp_start_crc() - start capture of frame CRCs
+ * @aux: DisplayPort AUX channel
+ *
+ * Returns 0 on success or a negative error code on failure.
+ */
+int drm_dp_start_crc(struct drm_dp_aux *aux)
+{
+	u8 buf;
+	int ret;
+
+	ret = drm_dp_dpcd_readb(aux, DP_TEST_SINK, &buf);
+	if (ret < 0)
+		return ret;
+
+	ret = drm_dp_dpcd_writeb(aux, DP_TEST_SINK, buf | DP_TEST_SINK_START);
+	if (ret < 0)
+		return ret;
+
+	aux->crc_count = 0;
+	schedule_work(&aux->crc_work);
+
+	return 0;
+}
+EXPORT_SYMBOL(drm_dp_start_crc);
+
+/**
+ * drm_dp_stop_crc() - stop capture of frame CRCs
+ * @aux: DisplayPort AUX channel
+ *
+ * Returns 0 on success or a negative error code on failure.
+ */
+int drm_dp_stop_crc(struct drm_dp_aux *aux)
+{
+	u8 buf;
+	int ret;
+
+	ret = drm_dp_dpcd_readb(aux, DP_TEST_SINK, &buf);
+	if (ret < 0)
+		return ret;
+
+	ret = drm_dp_dpcd_writeb(aux, DP_TEST_SINK, buf & ~DP_TEST_SINK_START);
+	if (ret < 0)
+		return ret;
+
+	flush_work(&aux->crc_work);
+
+	return 0;
+}
+EXPORT_SYMBOL(drm_dp_stop_crc);
diff --git a/include/drm/drm_dp_helper.h b/include/drm/drm_dp_helper.h
index eb598078bf89..7af40fea2ff9 100644
--- a/include/drm/drm_dp_helper.h
+++ b/include/drm/drm_dp_helper.h
@@ -734,6 +734,8 @@ struct drm_dp_aux_msg {
  * @dev: pointer to struct device that is the parent for this AUX channel
  * @connector: backpointer to connector that uses this AUX channel
  * @hw_mutex: internal mutex used for locking transfers
+ * @crc_work: worker that captures CRCs for each frame
+ * @crc_count: counter of captured frame CRCs
  * @transfer: transfers a message representing a single AUX transaction
  *
  * The .dev field should be set to a pointer to the device that implements
@@ -771,6 +773,8 @@ struct drm_dp_aux {
 	struct device *dev;
 	struct drm_connector *connector;
 	struct mutex hw_mutex;
+	struct work_struct crc_work;
+	u8 crc_count;
 	ssize_t (*transfer)(struct drm_dp_aux *aux,
 			    struct drm_dp_aux_msg *msg);
 	/**
@@ -849,4 +853,7 @@ void drm_dp_aux_init(struct drm_dp_aux *aux);
 int drm_dp_aux_register(struct drm_dp_aux *aux);
 void drm_dp_aux_unregister(struct drm_dp_aux *aux);
 
+int drm_dp_start_crc(struct drm_dp_aux *aux);
+int drm_dp_stop_crc(struct drm_dp_aux *aux);
+
 #endif /* _DRM_DP_HELPER_H_ */
-- 
2.9.3

[PATCH v5 3/4] drm/bridge: analogix_dp: add helpers for capture of frame CRCs

[Tomeu Vizoso]

Add two simple functions that just take the drm_dp_aux from our struct
and calls the corresponding DP helpers with it.

Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>
---

 drivers/gpu/drm/bridge/analogix/analogix_dp_core.c | 16 ++++++++++++++++
 include/drm/bridge/analogix_dp.h                   |  3 +++
 2 files changed, 19 insertions(+)

diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
index 44c2b74bf771..f5e0379d9abe 100644
--- a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
+++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
@@ -1490,6 +1490,22 @@ int analogix_dp_resume(struct device *dev)
 EXPORT_SYMBOL_GPL(analogix_dp_resume);
 #endif
 
+int analogix_dp_start_crc(struct drm_connector *connector)
+{
+	struct analogix_dp_device *dp = to_dp(connector);
+
+	return drm_dp_start_crc(&dp->aux);
+}
+EXPORT_SYMBOL_GPL(analogix_dp_start_crc);
+
+int analogix_dp_stop_crc(struct drm_connector *connector)
+{
+	struct analogix_dp_device *dp = to_dp(connector);
+
+	return drm_dp_stop_crc(&dp->aux);
+}
+EXPORT_SYMBOL_GPL(analogix_dp_stop_crc);
+
 MODULE_AUTHOR("Jingoo Han <jg1.han@samsung.com>");
 MODULE_DESCRIPTION("Analogix DP Core Driver");
 MODULE_LICENSE("GPL v2");
diff --git a/include/drm/bridge/analogix_dp.h b/include/drm/bridge/analogix_dp.h
index f6f0c062205c..c99d6eaef1ac 100644
--- a/include/drm/bridge/analogix_dp.h
+++ b/include/drm/bridge/analogix_dp.h
@@ -49,4 +49,7 @@ int analogix_dp_bind(struct device *dev, struct drm_device *drm_dev,
 		     struct analogix_dp_plat_data *plat_data);
 void analogix_dp_unbind(struct device *dev, struct device *master, void *data);
 
+int analogix_dp_start_crc(struct drm_connector *connector);
+int analogix_dp_stop_crc(struct drm_connector *connector);
+
 #endif /* _ANALOGIX_DP_H_ */
-- 
2.9.3

[PATCH v5 4/4] drm/rockchip: Implement CRC debugfs API

[Tomeu Vizoso]

Implement the .set_crc_source() callback and call the DP helpers
accordingly to start and stop CRC capture.

This is only done if this CRTC is currently using the eDP connector.

v3: Remove superfluous check on rockchip_crtc_state->output_type

Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>
---

 drivers/gpu/drm/rockchip/rockchip_drm_vop.c | 42 +++++++++++++++++++++++++++++
 1 file changed, 42 insertions(+)

diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_vop.c b/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
index fb5f001f51c3..6e5eb1aa182a 100644
--- a/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
+++ b/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
@@ -19,6 +19,7 @@
 #include <drm/drm_crtc_helper.h>
 #include <drm/drm_flip_work.h>
 #include <drm/drm_plane_helper.h>
+#include <drm/bridge/analogix_dp.h>
 
 #include <linux/kernel.h>
 #include <linux/module.h>
@@ -1105,6 +1106,46 @@ static void vop_crtc_destroy_state(struct drm_crtc *crtc,
 	kfree(s);
 }
 
+static struct drm_connector *vop_get_edp_connector(struct vop *vop)
+{
+	struct drm_crtc *crtc = &vop->crtc;
+	struct drm_connector *connector;
+
+	mutex_lock(&crtc->dev->mode_config.mutex);
+	drm_for_each_connector(connector, crtc->dev)
+		if (connector->connector_type == DRM_MODE_CONNECTOR_eDP) {
+			mutex_unlock(&crtc->dev->mode_config.mutex);
+			return connector;
+		}
+	mutex_unlock(&crtc->dev->mode_config.mutex);
+
+	return NULL;
+}
+
+static int vop_crtc_set_crc_source(struct drm_crtc *crtc,
+				   const char *source_name, size_t *values_cnt)
+{
+	struct vop *vop = to_vop(crtc);
+	struct rockchip_crtc_state *s = to_rockchip_crtc_state(crtc->state);
+	struct drm_connector *connector;
+	int ret;
+
+	connector = vop_get_edp_connector(vop);
+	if (!connector)
+		return -EINVAL;
+
+	*values_cnt = 3;
+
+	if (source_name && strcmp(source_name, "auto") == 0)
+		ret = analogix_dp_start_crc(connector);
+	else if (!source_name)
+		ret = analogix_dp_stop_crc(connector);
+	else
+		ret = -EINVAL;
+
+	return ret;
+}
+
 static const struct drm_crtc_funcs vop_crtc_funcs = {
 	.set_config = drm_atomic_helper_set_config,
 	.page_flip = drm_atomic_helper_page_flip,
@@ -1112,6 +1153,7 @@ static const struct drm_crtc_funcs vop_crtc_funcs = {
 	.reset = vop_crtc_reset,
 	.atomic_duplicate_state = vop_crtc_duplicate_state,
 	.atomic_destroy_state = vop_crtc_destroy_state,
+	.set_crc_source = vop_crtc_set_crc_source,
 };
 
 static void vop_fb_unref_worker(struct drm_flip_work *work, void *val)
-- 
2.9.3