drm/crc: Cleanup crtc_crc_open function

This patch make changes to allocate crc-entries buffer before
enabling CRC generation.
It moves all the failure check early in the function before setting
the source or memory allocation.
Now set_crc_source takes only two variable inputs, values_cnt we
already gets as part of verify_crc_source.

Changes since V1:
 - refactor code to use single spin lock
Changes since V2:
 - rebase
Changes since V3:
 - rebase on top of VKMS driver

Signed-off-by: Mahesh Kumar <mahesh1.kumar@intel.com>
Cc: dri-devel@lists.freedesktop.org
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Haneen Mohammed <hamohammed.sa@gmail.com>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Acked-by: Leo Li <sunpeng.li@amd.com> (V2)
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> (V3)
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180821083858.26275-3-mahesh1.kumar@intel.com

drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h

@@ -258,8 +258,7 @@ amdgpu_dm_remove_sink_from_freesync_module(struct drm_connector *connector);
 
 /* amdgpu_dm_crc.c */
 #ifdef CONFIG_DEBUG_FS
-int amdgpu_dm_crtc_set_crc_source(struct drm_crtc *crtc, const char *src_name,
-				  size_t *values_cnt);
+int amdgpu_dm_crtc_set_crc_source(struct drm_crtc *crtc, const char *src_name);
 int amdgpu_dm_crtc_verify_crc_source(struct drm_crtc *crtc,
 				     const char *src_name,
 				     size_t *values_cnt);

drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_crc.c

@@ -62,8 +62,7 @@ amdgpu_dm_crtc_verify_crc_source(struct drm_crtc *crtc, const char *src_name,
 	return 0;
 }
 
-int amdgpu_dm_crtc_set_crc_source(struct drm_crtc *crtc, const char *src_name,
-			   size_t *values_cnt)
+int amdgpu_dm_crtc_set_crc_source(struct drm_crtc *crtc, const char *src_name)
 {
 	struct dm_crtc_state *crtc_state = to_dm_crtc_state(crtc->state);
 	struct dc_stream_state *stream_state = crtc_state->stream;
@@ -99,7 +98,6 @@ int amdgpu_dm_crtc_set_crc_source(struct drm_crtc *crtc, const char *src_name,
 			return -EINVAL;
 	}
 
-	*values_cnt = 3;
 	/* Reset crc_skipped on dm state */
 	crtc_state->crc_skip_count = 0;
 	return 0;

drivers/gpu/drm/drm_debugfs_crc.c

@@ -127,11 +127,9 @@ static ssize_t crc_control_write(struct file *file, const char __user *ubuf,
 	if (source[len] == '\n')
 		source[len] = '\0';
 
-	if (crtc->funcs->verify_crc_source) {
-		ret = crtc->funcs->verify_crc_source(crtc, source, &values_cnt);
-		if (ret)
-			return ret;
-	}
+	ret = crtc->funcs->verify_crc_source(crtc, source, &values_cnt);
+	if (ret)
+		return ret;
 
 	spin_lock_irq(&crc->lock);
 
@@ -197,40 +195,40 @@ static int crtc_crc_open(struct inode *inode, struct file *filep)
 			return ret;
 	}
 
+	ret = crtc->funcs->verify_crc_source(crtc, crc->source, &values_cnt);
+	if (ret)
+		return ret;
+
+	if (WARN_ON(values_cnt > DRM_MAX_CRC_NR))
+		return -EINVAL;
+
+	if (WARN_ON(values_cnt == 0))
+		return -EINVAL;
+
+	entries = kcalloc(DRM_CRC_ENTRIES_NR, sizeof(*entries), GFP_KERNEL);
+	if (!entries)
+		return -ENOMEM;
+
 	spin_lock_irq(&crc->lock);
-	if (!crc->opened)
+	if (!crc->opened) {
 		crc->opened = true;
-	else
+		crc->entries = entries;
+		crc->values_cnt = values_cnt;
+	} else {
 		ret = -EBUSY;
+	}
 	spin_unlock_irq(&crc->lock);
 
-	if (ret)
+	if (ret) {
+		kfree(entries);
 		return ret;
+	}
 
-	ret = crtc->funcs->set_crc_source(crtc, crc->source, &values_cnt);
+	ret = crtc->funcs->set_crc_source(crtc, crc->source);
 	if (ret)
 		goto err;
 
-	if (WARN_ON(values_cnt > DRM_MAX_CRC_NR)) {
-		ret = -EINVAL;
-		goto err_disable;
-	}
-
-	if (WARN_ON(values_cnt == 0)) {
-		ret = -EINVAL;
-		goto err_disable;
-	}
-
-	entries = kcalloc(DRM_CRC_ENTRIES_NR, sizeof(*entries), GFP_KERNEL);
-	if (!entries) {
-		ret = -ENOMEM;
-		goto err_disable;
-	}
-
 	spin_lock_irq(&crc->lock);
-	crc->entries = entries;
-	crc->values_cnt = values_cnt;
-
 	/*
 	 * Only return once we got a first frame, so userspace doesn't have to
 	 * guess when this particular piece of HW will be ready to start
@@ -247,7 +245,7 @@ static int crtc_crc_open(struct inode *inode, struct file *filep)
 	return 0;
 
 err_disable:
-	crtc->funcs->set_crc_source(crtc, NULL, &values_cnt);
+	crtc->funcs->set_crc_source(crtc, NULL);
 err:
 	spin_lock_irq(&crc->lock);
 	crtc_crc_cleanup(crc);
@@ -259,9 +257,8 @@ static int crtc_crc_release(struct inode *inode, struct file *filep)
 {
 	struct drm_crtc *crtc = filep->f_inode->i_private;
 	struct drm_crtc_crc *crc = &crtc->crc;
-	size_t values_cnt;
 
-	crtc->funcs->set_crc_source(crtc, NULL, &values_cnt);
+	crtc->funcs->set_crc_source(crtc, NULL);
 
 	spin_lock_irq(&crc->lock);
 	crtc_crc_cleanup(crc);
@@ -367,7 +364,7 @@ int drm_debugfs_crtc_crc_add(struct drm_crtc *crtc)
 {
 	struct dentry *crc_ent, *ent;
 
-	if (!crtc->funcs->set_crc_source)
+	if (!crtc->funcs->set_crc_source || !crtc->funcs->verify_crc_source)
 		return 0;
 
 	crc_ent = debugfs_create_dir("crc", crtc->debugfs_entry);

drivers/gpu/drm/i915/intel_drv.h

@@ -2151,8 +2151,7 @@ void lspcon_wait_pcon_mode(struct intel_lspcon *lspcon);
 /* intel_pipe_crc.c */
 int intel_pipe_crc_create(struct drm_minor *minor);
 #ifdef CONFIG_DEBUG_FS
-int intel_crtc_set_crc_source(struct drm_crtc *crtc, const char *source_name,
-			      size_t *values_cnt);
+int intel_crtc_set_crc_source(struct drm_crtc *crtc, const char *source_name);
 int intel_crtc_verify_crc_source(struct drm_crtc *crtc,
 				 const char *source_name, size_t *values_cnt);
 const char *const *intel_crtc_get_crc_sources(struct drm_crtc *crtc,

drivers/gpu/drm/i915/intel_pipe_crc.c

@@ -1028,8 +1028,7 @@ int intel_crtc_verify_crc_source(struct drm_crtc *crtc, const char *source_name,
 	return -EINVAL;
 }
 
-int intel_crtc_set_crc_source(struct drm_crtc *crtc, const char *source_name,
-			      size_t *values_cnt)
+int intel_crtc_set_crc_source(struct drm_crtc *crtc, const char *source_name)
 {
 	struct drm_i915_private *dev_priv = to_i915(crtc->dev);
 	struct intel_pipe_crc *pipe_crc = &dev_priv->pipe_crc[crtc->index];
@@ -1068,7 +1067,6 @@ int intel_crtc_set_crc_source(struct drm_crtc *crtc, const char *source_name,
 	}
 
 	pipe_crc->skipped = 0;
-	*values_cnt = 5;
 
 out:
 	intel_display_power_put(dev_priv, power_domain);

drivers/gpu/drm/rcar-du/rcar_du_crtc.c

@@ -887,8 +887,7 @@ const char *const *rcar_du_crtc_get_crc_sources(struct drm_crtc *crtc,
 }
 
 static int rcar_du_crtc_set_crc_source(struct drm_crtc *crtc,
-				       const char *source_name,
-				       size_t *values_cnt)
+				       const char *source_name)
 {
 	struct rcar_du_crtc *rcrtc = to_rcar_crtc(crtc);
 	struct drm_modeset_acquire_ctx ctx;
@@ -903,7 +902,6 @@ static int rcar_du_crtc_set_crc_source(struct drm_crtc *crtc,
 		return ret;
 
 	index = ret;
-	*values_cnt = 1;
 
 	/* Perform an atomic commit to set the CRC source. */
 	drm_modeset_acquire_init(&ctx, 0);

drivers/gpu/drm/rockchip/rockchip_drm_vop.c

@@ -1111,7 +1111,7 @@ static struct drm_connector *vop_get_edp_connector(struct vop *vop)
 }
 
 static int vop_crtc_set_crc_source(struct drm_crtc *crtc,
-				   const char *source_name, size_t *values_cnt)
+				   const char *source_name)
 {
 	struct vop *vop = to_vop(crtc);
 	struct drm_connector *connector;
@@ -1121,8 +1121,6 @@ static int vop_crtc_set_crc_source(struct drm_crtc *crtc,
 	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)
@@ -1146,7 +1144,7 @@ vop_crtc_verify_crc_source(struct drm_crtc *crtc, const char *source_name,
 
 #else
 static int vop_crtc_set_crc_source(struct drm_crtc *crtc,
-				   const char *source_name, size_t *values_cnt)
+				   const char *source_name)
 {
 	return -ENODEV;
 }

drivers/gpu/drm/vkms/vkms_crc.c

@@ -101,8 +101,7 @@ int vkms_verify_crc_source(struct drm_crtc *crtc, const char *src_name,
 	return 0;
 }
 
-int vkms_set_crc_source(struct drm_crtc *crtc, const char *src_name,
-			size_t *values_cnt)
+int vkms_set_crc_source(struct drm_crtc *crtc, const char *src_name)
 {
 	struct vkms_output *out = drm_crtc_to_vkms_output(crtc);
 	bool enabled = false;
@@ -111,8 +110,6 @@ int vkms_set_crc_source(struct drm_crtc *crtc, const char *src_name,
 
 	ret = vkms_crc_parse_source(src_name, &enabled);
 
-	*values_cnt = 1;
-
 	/* make sure nothing is scheduled on crtc workq */
 	flush_workqueue(out->crc_workq);
 

drivers/gpu/drm/vkms/vkms_drv.h

@@ -123,8 +123,7 @@ int vkms_gem_vmap(struct drm_gem_object *obj);
 void vkms_gem_vunmap(struct drm_gem_object *obj);
 
 /* CRC Support */
-int vkms_set_crc_source(struct drm_crtc *crtc, const char *src_name,
-			size_t *values_cnt);
+int vkms_set_crc_source(struct drm_crtc *crtc, const char *src_name);
 int vkms_verify_crc_source(struct drm_crtc *crtc, const char *source_name,
 			   size_t *values_cnt);
 void vkms_crc_work_handle(struct work_struct *work);

include/drm/drm_crtc.h

@@ -744,8 +744,7 @@ struct drm_crtc_funcs {
 	 *
 	 * 0 on success or a negative error code on failure.
 	 */
-	int (*set_crc_source)(struct drm_crtc *crtc, const char *source,
-			      size_t *values_cnt);
+	int (*set_crc_source)(struct drm_crtc *crtc, const char *source);
 	/**
 	 * @verify_crc_source:
 	 *