[PATCH 0/4] drm: atomic fb-helper support

[PATCH 0/4] drm: atomic fb-helper support

[Rob Clark]

Convert fb-helper, or at least the two code-paths which potentially
trigger more than a single update, to use atomic API if the driver
supports it.

The first patch is slightly unrelated, but I needed to add kerneldoc
for 'struct drm_fb_helper' before I could add kerneldoc for the new
atomic field.  Danvet tricked me into writing some kerneldoc that
way.

In theory, after this, we can re-introduce the ww_acquire_fini()
call.

Rob Clark (4):
  drm/fb-helper: add headerdoc for drm_fb_helper
  drm/fb-helper: atomic restore_fbdev_mode()..
  drm/fb-helper: atomic pan_display()..
  drm/i915: enable atomic fb-helper

 drivers/gpu/drm/drm_atomic_helper.c | 131 +++++++++++++++++++++---------------
 drivers/gpu/drm/drm_fb_helper.c     | 131 ++++++++++++++++++++++++++++++++++++
 drivers/gpu/drm/i915/intel_fbdev.c  |   2 +
 include/drm/drm_atomic_helper.h     |   6 ++
 include/drm/drm_fb_helper.h         |  22 ++++++
 5 files changed, 239 insertions(+), 53 deletions(-)

-- 
2.4.3

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[PATCH 1/4] drm/fb-helper: add headerdoc for drm_fb_helper

[Rob Clark]

Signed-off-by: Rob Clark <robdclark@gmail.com>
---
 include/drm/drm_fb_helper.h | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/include/drm/drm_fb_helper.h b/include/drm/drm_fb_helper.h
index 67de1f1..6254136 100644
--- a/include/drm/drm_fb_helper.h
+++ b/include/drm/drm_fb_helper.h
@@ -104,6 +104,20 @@ struct drm_fb_helper_connector {
 	struct drm_connector *connector;
 };
 
+/**
+ * struct drm_fb_helper - helper to emulate fbdev on top of kms
+ * @fb:  Scanout framebuffer object
+ * @dev:  DRM device
+ * @crtc_count: number of possible CRTCs
+ * @crtc_info: per-CRTC helper state (mode, x/y offset, etc)
+ * @connector_count: number of connected connectors
+ * @connector_info_alloc_count: size of connector_info
+ * @funcs: driver callbacks for fb helper
+ * @fbdev: emulated fbdev device info struct
+ * @pseudo_palette: fake palette of 16 colors
+ * @kernel_fb_list: list_head in kernel_fb_helper_list
+ * @delayed_hotplug: was there a hotplug while kms master active?
+ */
 struct drm_fb_helper {
 	struct drm_framebuffer *fb;
 	struct drm_device *dev;
-- 
2.4.3

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[PATCH 2/4] drm/fb-helper: atomic restore_fbdev_mode()..

[Rob Clark]

Add support for using atomic code-paths for restore_fbdev_mode().

Signed-off-by: Rob Clark <robdclark@gmail.com>
---
 drivers/gpu/drm/drm_atomic_helper.c | 131 +++++++++++++++++++++---------------
 drivers/gpu/drm/drm_fb_helper.c     |  74 ++++++++++++++++++++
 include/drm/drm_atomic_helper.h     |   6 ++
 include/drm/drm_fb_helper.h         |   8 +++
 4 files changed, 166 insertions(+), 53 deletions(-)

diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c
index d432348..dbce582 100644
--- a/drivers/gpu/drm/drm_atomic_helper.c
+++ b/drivers/gpu/drm/drm_atomic_helper.c
@@ -1502,21 +1502,9 @@ retry:
 		goto fail;
 	}
 
-	ret = drm_atomic_set_crtc_for_plane(plane_state, NULL);
+	ret = __drm_atomic_helper_disable_plane(plane, plane_state);
 	if (ret != 0)
 		goto fail;
-	drm_atomic_set_fb_for_plane(plane_state, NULL);
-	plane_state->crtc_x = 0;
-	plane_state->crtc_y = 0;
-	plane_state->crtc_h = 0;
-	plane_state->crtc_w = 0;
-	plane_state->src_x = 0;
-	plane_state->src_y = 0;
-	plane_state->src_h = 0;
-	plane_state->src_w = 0;
-
-	if (plane == plane->crtc->cursor)
-		state->legacy_cursor_update = true;
 
 	ret = drm_atomic_commit(state);
 	if (ret != 0)
@@ -1546,6 +1534,32 @@ backoff:
 }
 EXPORT_SYMBOL(drm_atomic_helper_disable_plane);
 
+/* just used from fb-helper and atomic-helper: */
+int __drm_atomic_helper_disable_plane(struct drm_plane *plane,
+		struct drm_plane_state *plane_state)
+{
+	int ret;
+
+	ret = drm_atomic_set_crtc_for_plane(plane_state, NULL);
+	if (ret != 0)
+		return ret;
+
+	drm_atomic_set_fb_for_plane(plane_state, NULL);
+	plane_state->crtc_x = 0;
+	plane_state->crtc_y = 0;
+	plane_state->crtc_h = 0;
+	plane_state->crtc_w = 0;
+	plane_state->src_x = 0;
+	plane_state->src_y = 0;
+	plane_state->src_h = 0;
+	plane_state->src_w = 0;
+
+	if (plane->crtc && (plane == plane->crtc->cursor))
+		plane_state->state->legacy_cursor_update = true;
+
+	return 0;
+}
+
 static int update_output_state(struct drm_atomic_state *state,
 			       struct drm_mode_set *set)
 {
@@ -1629,8 +1643,6 @@ int drm_atomic_helper_set_config(struct drm_mode_set *set)
 {
 	struct drm_atomic_state *state;
 	struct drm_crtc *crtc = set->crtc;
-	struct drm_crtc_state *crtc_state;
-	struct drm_plane_state *primary_state;
 	int ret = 0;
 
 	state = drm_atomic_state_alloc(crtc->dev);
@@ -1639,17 +1651,54 @@ int drm_atomic_helper_set_config(struct drm_mode_set *set)
 
 	state->acquire_ctx = drm_modeset_legacy_acquire_ctx(crtc);
 retry:
-	crtc_state = drm_atomic_get_crtc_state(state, crtc);
-	if (IS_ERR(crtc_state)) {
-		ret = PTR_ERR(crtc_state);
+	ret = __drm_atomic_helper_set_config(set, state);
+	if (ret != 0)
 		goto fail;
-	}
 
-	primary_state = drm_atomic_get_plane_state(state, crtc->primary);
-	if (IS_ERR(primary_state)) {
-		ret = PTR_ERR(primary_state);
+	ret = drm_atomic_commit(state);
+	if (ret != 0)
 		goto fail;
-	}
+
+	/* Driver takes ownership of state on successful commit. */
+	return 0;
+fail:
+	if (ret == -EDEADLK)
+		goto backoff;
+
+	drm_atomic_state_free(state);
+
+	return ret;
+backoff:
+	drm_atomic_state_clear(state);
+	drm_atomic_legacy_backoff(state);
+
+	/*
+	 * Someone might have exchanged the framebuffer while we dropped locks
+	 * in the backoff code. We need to fix up the fb refcount tracking the
+	 * core does for us.
+	 */
+	crtc->primary->old_fb = crtc->primary->fb;
+
+	goto retry;
+}
+EXPORT_SYMBOL(drm_atomic_helper_set_config);
+
+/* just used from fb-helper and atomic-helper: */
+int __drm_atomic_helper_set_config(struct drm_mode_set *set,
+		struct drm_atomic_state *state)
+{
+	struct drm_crtc_state *crtc_state;
+	struct drm_plane_state *primary_state;
+	struct drm_crtc *crtc = set->crtc;
+	int ret;
+
+	crtc_state = drm_atomic_get_crtc_state(state, crtc);
+	if (IS_ERR(crtc_state))
+		return PTR_ERR(crtc_state);
+
+	primary_state = drm_atomic_get_plane_state(state, crtc->primary);
+	if (IS_ERR(primary_state))
+		return PTR_ERR(primary_state);
 
 	if (!set->mode) {
 		WARN_ON(set->fb);
@@ -1657,13 +1706,13 @@ retry:
 
 		ret = drm_atomic_set_mode_for_crtc(crtc_state, NULL);
 		if (ret != 0)
-			goto fail;
+			return ret;
 
 		crtc_state->active = false;
 
 		ret = drm_atomic_set_crtc_for_plane(primary_state, NULL);
 		if (ret != 0)
-			goto fail;
+			return ret;
 
 		drm_atomic_set_fb_for_plane(primary_state, NULL);
 
@@ -1675,13 +1724,14 @@ retry:
 
 	ret = drm_atomic_set_mode_for_crtc(crtc_state, set->mode);
 	if (ret != 0)
-		goto fail;
+		return ret;
 
 	crtc_state->active = true;
 
 	ret = drm_atomic_set_crtc_for_plane(primary_state, crtc);
 	if (ret != 0)
-		goto fail;
+		return ret;
+
 	drm_atomic_set_fb_for_plane(primary_state, set->fb);
 	primary_state->crtc_x = 0;
 	primary_state->crtc_y = 0;
@@ -1695,35 +1745,10 @@ retry:
 commit:
 	ret = update_output_state(state, set);
 	if (ret)
-		goto fail;
-
-	ret = drm_atomic_commit(state);
-	if (ret != 0)
-		goto fail;
+		return ret;
 
-	/* Driver takes ownership of state on successful commit. */
 	return 0;
-fail:
-	if (ret == -EDEADLK)
-		goto backoff;
-
-	drm_atomic_state_free(state);
-
-	return ret;
-backoff:
-	drm_atomic_state_clear(state);
-	drm_atomic_legacy_backoff(state);
-
-	/*
-	 * Someone might have exchanged the framebuffer while we dropped locks
-	 * in the backoff code. We need to fix up the fb refcount tracking the
-	 * core does for us.
-	 */
-	crtc->primary->old_fb = crtc->primary->fb;
-
-	goto retry;
 }
-EXPORT_SYMBOL(drm_atomic_helper_set_config);
 
 /**
  * drm_atomic_helper_crtc_set_property - helper for crtc properties
diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
index ba12f51..9741d79 100644
--- a/drivers/gpu/drm/drm_fb_helper.c
+++ b/drivers/gpu/drm/drm_fb_helper.c
@@ -38,6 +38,8 @@
 #include <drm/drm_crtc.h>
 #include <drm/drm_fb_helper.h>
 #include <drm/drm_crtc_helper.h>
+#include <drm/drm_atomic.h>
+#include <drm/drm_atomic_helper.h>
 
 static bool drm_fbdev_emulation = true;
 module_param_named(fbdev_emulation, drm_fbdev_emulation, bool, 0600);
@@ -334,6 +336,73 @@ int drm_fb_helper_debug_leave(struct fb_info *info)
 }
 EXPORT_SYMBOL(drm_fb_helper_debug_leave);
 
+static int restore_fbdev_mode_atomic(struct drm_fb_helper *fb_helper)
+{
+	struct drm_device *dev = fb_helper->dev;
+	struct drm_plane *plane;
+	struct drm_atomic_state *state;
+	int i, ret;
+
+	state = drm_atomic_state_alloc(dev);
+	if (!state)
+		return -ENOMEM;
+
+	state->acquire_ctx = dev->mode_config.acquire_ctx;
+retry:
+	drm_for_each_plane(plane, dev) {
+		struct drm_plane_state *plane_state;
+
+		plane_state = drm_atomic_get_plane_state(state, plane);
+		if (IS_ERR(plane_state)) {
+			ret = PTR_ERR(plane_state);
+			goto fail;
+		}
+
+		/* reset rotation: */
+		ret = drm_atomic_plane_set_property(plane, plane_state,
+				dev->mode_config.rotation_property,
+				BIT(DRM_ROTATE_0));
+		if (ret != 0)
+			goto fail;
+
+		/* disable non-primary: */
+		if (plane->type == DRM_PLANE_TYPE_PRIMARY)
+			continue;
+
+		ret = __drm_atomic_helper_disable_plane(plane, plane_state);
+		if (ret != 0)
+			goto fail;
+	}
+
+	for(i = 0; i < fb_helper->crtc_count; i++) {
+		struct drm_mode_set *mode_set = &fb_helper->crtc_info[i].mode_set;
+
+		ret = __drm_atomic_helper_set_config(mode_set, state);
+		if (ret != 0)
+			goto fail;
+	}
+
+	ret = drm_atomic_commit(state);
+	if (ret != 0)
+		goto fail;
+
+	return 0;
+
+fail:
+	if (ret == -EDEADLK)
+		goto backoff;
+
+	drm_atomic_state_free(state);
+
+	return ret;
+
+backoff:
+	drm_atomic_state_clear(state);
+	drm_atomic_legacy_backoff(state);
+
+	goto retry;
+}
+
 static int restore_fbdev_mode(struct drm_fb_helper *fb_helper)
 {
 	struct drm_device *dev = fb_helper->dev;
@@ -342,6 +411,9 @@ static int restore_fbdev_mode(struct drm_fb_helper *fb_helper)
 
 	drm_warn_on_modeset_not_all_locked(dev);
 
+	if (fb_helper->atomic)
+		return restore_fbdev_mode_atomic(fb_helper);
+
 	drm_for_each_plane(plane, dev) {
 		if (plane->type != DRM_PLANE_TYPE_PRIMARY)
 			drm_plane_force_disable(plane);
@@ -644,6 +716,8 @@ int drm_fb_helper_init(struct drm_device *dev,
 		i++;
 	}
 
+	fb_helper->atomic = !!drm_core_check_feature(dev, DRIVER_ATOMIC);
+
 	return 0;
 out_free:
 	drm_fb_helper_crtc_free(fb_helper);
diff --git a/include/drm/drm_atomic_helper.h b/include/drm/drm_atomic_helper.h
index 11266d14..88c0ef3 100644
--- a/include/drm/drm_atomic_helper.h
+++ b/include/drm/drm_atomic_helper.h
@@ -30,6 +30,8 @@
 
 #include <drm/drm_crtc.h>
 
+struct drm_atomic_state;
+
 int drm_atomic_helper_check_modeset(struct drm_device *dev,
 				struct drm_atomic_state *state);
 int drm_atomic_helper_check_planes(struct drm_device *dev,
@@ -72,7 +74,11 @@ int drm_atomic_helper_update_plane(struct drm_plane *plane,
 				   uint32_t src_x, uint32_t src_y,
 				   uint32_t src_w, uint32_t src_h);
 int drm_atomic_helper_disable_plane(struct drm_plane *plane);
+int __drm_atomic_helper_disable_plane(struct drm_plane *plane,
+		struct drm_plane_state *plane_state);
 int drm_atomic_helper_set_config(struct drm_mode_set *set);
+int __drm_atomic_helper_set_config(struct drm_mode_set *set,
+		struct drm_atomic_state *state);
 
 int drm_atomic_helper_crtc_set_property(struct drm_crtc *crtc,
 					struct drm_property *property,
diff --git a/include/drm/drm_fb_helper.h b/include/drm/drm_fb_helper.h
index 6254136..cc3d820 100644
--- a/include/drm/drm_fb_helper.h
+++ b/include/drm/drm_fb_helper.h
@@ -117,6 +117,12 @@ struct drm_fb_helper_connector {
  * @pseudo_palette: fake palette of 16 colors
  * @kernel_fb_list: list_head in kernel_fb_helper_list
  * @delayed_hotplug: was there a hotplug while kms master active?
+ * @atomic: use atomic updates for restore_fbdev_mode(), etc.  This
+ *          defaults to true if driver has DRIVER_ATOMIC feature
+ *          flag, but drivers can override it to true after
+ *          drm_fb_helper_init() if they support atomic modeset
+ *          but do not yet advertise DRIVER_ATOMIC (note that
+ *          fb-helper does not require ASYNC commits).
  */
 struct drm_fb_helper {
 	struct drm_framebuffer *fb;
@@ -134,6 +140,8 @@ struct drm_fb_helper {
 	/* we got a hotplug but fbdev wasn't running the console
 	   delay until next set_par */
 	bool delayed_hotplug;
+
+	bool atomic;
 };
 
 #ifdef CONFIG_DRM_FBDEV_EMULATION
-- 
2.4.3

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[PATCH 3/4] drm/fb-helper: atomic pan_display()..

[Rob Clark]

Signed-off-by: Rob Clark <robdclark@gmail.com>
---
 drivers/gpu/drm/drm_fb_helper.c | 57 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 57 insertions(+)

diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
index 9741d79..efc4d33 100644
--- a/drivers/gpu/drm/drm_fb_helper.c
+++ b/drivers/gpu/drm/drm_fb_helper.c
@@ -1218,6 +1218,57 @@ int drm_fb_helper_set_par(struct fb_info *info)
 }
 EXPORT_SYMBOL(drm_fb_helper_set_par);
 
+static int pan_display_atomic(struct fb_var_screeninfo *var,
+		struct fb_info *info)
+{
+	struct drm_fb_helper *fb_helper = info->par;
+	struct drm_device *dev = fb_helper->dev;
+	struct drm_atomic_state *state;
+	int i, ret;
+
+	state = drm_atomic_state_alloc(dev);
+	if (!state)
+		return -ENOMEM;
+
+	state->acquire_ctx = dev->mode_config.acquire_ctx;
+retry:
+	for(i = 0; i < fb_helper->crtc_count; i++) {
+		struct drm_mode_set *mode_set;
+
+		mode_set = &fb_helper->crtc_info[i].mode_set;
+
+		mode_set->x = var->xoffset;
+		mode_set->y = var->yoffset;
+
+		ret = __drm_atomic_helper_set_config(mode_set, state);
+		if (ret != 0)
+			goto fail;
+	}
+
+	ret = drm_atomic_commit(state);
+	if (ret != 0)
+		goto fail;
+
+	info->var.xoffset = var->xoffset;
+	info->var.yoffset = var->yoffset;
+
+	return 0;
+
+fail:
+	if (ret == -EDEADLK)
+		goto backoff;
+
+	drm_atomic_state_free(state);
+
+	return ret;
+
+backoff:
+	drm_atomic_state_clear(state);
+	drm_atomic_legacy_backoff(state);
+
+	goto retry;
+}
+
 /**
  * drm_fb_helper_pan_display - implementation for ->fb_pan_display
  * @var: updated screen information
@@ -1241,6 +1292,11 @@ int drm_fb_helper_pan_display(struct fb_var_screeninfo *var,
 		return -EBUSY;
 	}
 
+	if (fb_helper->atomic) {
+		ret = pan_display_atomic(var, info);
+		goto unlock;
+	}
+
 	for (i = 0; i < fb_helper->crtc_count; i++) {
 		modeset = &fb_helper->crtc_info[i].mode_set;
 
@@ -1255,6 +1311,7 @@ int drm_fb_helper_pan_display(struct fb_var_screeninfo *var,
 			}
 		}
 	}
+unlock:
 	drm_modeset_unlock_all(dev);
 	return ret;
 }
-- 
2.4.3

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[PATCH 4/4] drm/i915: enable atomic fb-helper

[Rob Clark]

i915 supports enough atomic to have atomic fb-helper paths, even though
it does not yet advertise DRIVER_ATOMIC.

Signed-off-by: Rob Clark <robdclark@gmail.com>
---
 drivers/gpu/drm/i915/intel_fbdev.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/gpu/drm/i915/intel_fbdev.c b/drivers/gpu/drm/i915/intel_fbdev.c
index 8c6a6fa..ab2b856 100644
--- a/drivers/gpu/drm/i915/intel_fbdev.c
+++ b/drivers/gpu/drm/i915/intel_fbdev.c
@@ -689,6 +689,8 @@ int intel_fbdev_init(struct drm_device *dev)
 		return ret;
 	}
 
+	ifbdev->helper.atomic = true;
+
 	dev_priv->fbdev = ifbdev;
 	INIT_WORK(&dev_priv->fbdev_suspend_work, intel_fbdev_suspend_worker);
 
-- 
2.4.3

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Re: [PATCH 2/4] drm/fb-helper: atomic restore_fbdev_mode()..

[Daniel Vetter]

On Tue, Aug 25, 2015 at 03:35:58PM -0400, Rob Clark wrote:
> Add support for using atomic code-paths for restore_fbdev_mode().
> 
> Signed-off-by: Rob Clark <robdclark@gmail.com>
> ---
>  drivers/gpu/drm/drm_atomic_helper.c | 131 +++++++++++++++++++++---------------
>  drivers/gpu/drm/drm_fb_helper.c     |  74 ++++++++++++++++++++
>  include/drm/drm_atomic_helper.h     |   6 ++
>  include/drm/drm_fb_helper.h         |   8 +++
>  4 files changed, 166 insertions(+), 53 deletions(-)
> 
> diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c
> index d432348..dbce582 100644
> --- a/drivers/gpu/drm/drm_atomic_helper.c
> +++ b/drivers/gpu/drm/drm_atomic_helper.c
> @@ -1502,21 +1502,9 @@ retry:
>  		goto fail;
>  	}
>  
> -	ret = drm_atomic_set_crtc_for_plane(plane_state, NULL);
> +	ret = __drm_atomic_helper_disable_plane(plane, plane_state);
>  	if (ret != 0)
>  		goto fail;
> -	drm_atomic_set_fb_for_plane(plane_state, NULL);
> -	plane_state->crtc_x = 0;
> -	plane_state->crtc_y = 0;
> -	plane_state->crtc_h = 0;
> -	plane_state->crtc_w = 0;
> -	plane_state->src_x = 0;
> -	plane_state->src_y = 0;
> -	plane_state->src_h = 0;
> -	plane_state->src_w = 0;
> -
> -	if (plane == plane->crtc->cursor)
> -		state->legacy_cursor_update = true;
>  
>  	ret = drm_atomic_commit(state);
>  	if (ret != 0)
> @@ -1546,6 +1534,32 @@ backoff:
>  }
>  EXPORT_SYMBOL(drm_atomic_helper_disable_plane);
>  
> +/* just used from fb-helper and atomic-helper: */
> +int __drm_atomic_helper_disable_plane(struct drm_plane *plane,
> +		struct drm_plane_state *plane_state)
> +{
> +	int ret;
> +
> +	ret = drm_atomic_set_crtc_for_plane(plane_state, NULL);
> +	if (ret != 0)
> +		return ret;
> +
> +	drm_atomic_set_fb_for_plane(plane_state, NULL);
> +	plane_state->crtc_x = 0;
> +	plane_state->crtc_y = 0;
> +	plane_state->crtc_h = 0;
> +	plane_state->crtc_w = 0;
> +	plane_state->src_x = 0;
> +	plane_state->src_y = 0;
> +	plane_state->src_h = 0;
> +	plane_state->src_w = 0;
> +
> +	if (plane->crtc && (plane == plane->crtc->cursor))
> +		plane_state->state->legacy_cursor_update = true;
> +
> +	return 0;
> +}
> +
>  static int update_output_state(struct drm_atomic_state *state,
>  			       struct drm_mode_set *set)
>  {
> @@ -1629,8 +1643,6 @@ int drm_atomic_helper_set_config(struct drm_mode_set *set)
>  {
>  	struct drm_atomic_state *state;
>  	struct drm_crtc *crtc = set->crtc;
> -	struct drm_crtc_state *crtc_state;
> -	struct drm_plane_state *primary_state;
>  	int ret = 0;
>  
>  	state = drm_atomic_state_alloc(crtc->dev);
> @@ -1639,17 +1651,54 @@ int drm_atomic_helper_set_config(struct drm_mode_set *set)
>  
>  	state->acquire_ctx = drm_modeset_legacy_acquire_ctx(crtc);
>  retry:
> -	crtc_state = drm_atomic_get_crtc_state(state, crtc);
> -	if (IS_ERR(crtc_state)) {
> -		ret = PTR_ERR(crtc_state);
> +	ret = __drm_atomic_helper_set_config(set, state);
> +	if (ret != 0)
>  		goto fail;
> -	}
>  
> -	primary_state = drm_atomic_get_plane_state(state, crtc->primary);
> -	if (IS_ERR(primary_state)) {
> -		ret = PTR_ERR(primary_state);
> +	ret = drm_atomic_commit(state);
> +	if (ret != 0)
>  		goto fail;
> -	}
> +
> +	/* Driver takes ownership of state on successful commit. */
> +	return 0;
> +fail:
> +	if (ret == -EDEADLK)
> +		goto backoff;
> +
> +	drm_atomic_state_free(state);
> +
> +	return ret;
> +backoff:
> +	drm_atomic_state_clear(state);
> +	drm_atomic_legacy_backoff(state);
> +
> +	/*
> +	 * Someone might have exchanged the framebuffer while we dropped locks
> +	 * in the backoff code. We need to fix up the fb refcount tracking the
> +	 * core does for us.
> +	 */
> +	crtc->primary->old_fb = crtc->primary->fb;
> +
> +	goto retry;
> +}
> +EXPORT_SYMBOL(drm_atomic_helper_set_config);
> +
> +/* just used from fb-helper and atomic-helper: */
> +int __drm_atomic_helper_set_config(struct drm_mode_set *set,
> +		struct drm_atomic_state *state)
> +{
> +	struct drm_crtc_state *crtc_state;
> +	struct drm_plane_state *primary_state;
> +	struct drm_crtc *crtc = set->crtc;
> +	int ret;
> +
> +	crtc_state = drm_atomic_get_crtc_state(state, crtc);
> +	if (IS_ERR(crtc_state))
> +		return PTR_ERR(crtc_state);
> +
> +	primary_state = drm_atomic_get_plane_state(state, crtc->primary);
> +	if (IS_ERR(primary_state))
> +		return PTR_ERR(primary_state);
>  
>  	if (!set->mode) {
>  		WARN_ON(set->fb);
> @@ -1657,13 +1706,13 @@ retry:
>  
>  		ret = drm_atomic_set_mode_for_crtc(crtc_state, NULL);
>  		if (ret != 0)
> -			goto fail;
> +			return ret;
>  
>  		crtc_state->active = false;
>  
>  		ret = drm_atomic_set_crtc_for_plane(primary_state, NULL);
>  		if (ret != 0)
> -			goto fail;
> +			return ret;
>  
>  		drm_atomic_set_fb_for_plane(primary_state, NULL);
>  
> @@ -1675,13 +1724,14 @@ retry:
>  
>  	ret = drm_atomic_set_mode_for_crtc(crtc_state, set->mode);
>  	if (ret != 0)
> -		goto fail;
> +		return ret;
>  
>  	crtc_state->active = true;
>  
>  	ret = drm_atomic_set_crtc_for_plane(primary_state, crtc);
>  	if (ret != 0)
> -		goto fail;
> +		return ret;
> +
>  	drm_atomic_set_fb_for_plane(primary_state, set->fb);
>  	primary_state->crtc_x = 0;
>  	primary_state->crtc_y = 0;
> @@ -1695,35 +1745,10 @@ retry:
>  commit:
>  	ret = update_output_state(state, set);
>  	if (ret)
> -		goto fail;
> -
> -	ret = drm_atomic_commit(state);
> -	if (ret != 0)
> -		goto fail;
> +		return ret;
>  
> -	/* Driver takes ownership of state on successful commit. */
>  	return 0;
> -fail:
> -	if (ret == -EDEADLK)
> -		goto backoff;
> -
> -	drm_atomic_state_free(state);
> -
> -	return ret;
> -backoff:
> -	drm_atomic_state_clear(state);
> -	drm_atomic_legacy_backoff(state);
> -
> -	/*
> -	 * Someone might have exchanged the framebuffer while we dropped locks
> -	 * in the backoff code. We need to fix up the fb refcount tracking the
> -	 * core does for us.
> -	 */
> -	crtc->primary->old_fb = crtc->primary->fb;
> -
> -	goto retry;
>  }
> -EXPORT_SYMBOL(drm_atomic_helper_set_config);
>  
>  /**
>   * drm_atomic_helper_crtc_set_property - helper for crtc properties
> diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
> index ba12f51..9741d79 100644
> --- a/drivers/gpu/drm/drm_fb_helper.c
> +++ b/drivers/gpu/drm/drm_fb_helper.c
> @@ -38,6 +38,8 @@
>  #include <drm/drm_crtc.h>
>  #include <drm/drm_fb_helper.h>
>  #include <drm/drm_crtc_helper.h>
> +#include <drm/drm_atomic.h>
> +#include <drm/drm_atomic_helper.h>
>  
>  static bool drm_fbdev_emulation = true;
>  module_param_named(fbdev_emulation, drm_fbdev_emulation, bool, 0600);
> @@ -334,6 +336,73 @@ int drm_fb_helper_debug_leave(struct fb_info *info)
>  }
>  EXPORT_SYMBOL(drm_fb_helper_debug_leave);
>  
> +static int restore_fbdev_mode_atomic(struct drm_fb_helper *fb_helper)
> +{
> +	struct drm_device *dev = fb_helper->dev;
> +	struct drm_plane *plane;
> +	struct drm_atomic_state *state;
> +	int i, ret;
> +
> +	state = drm_atomic_state_alloc(dev);
> +	if (!state)
> +		return -ENOMEM;
> +
> +	state->acquire_ctx = dev->mode_config.acquire_ctx;
> +retry:
> +	drm_for_each_plane(plane, dev) {
> +		struct drm_plane_state *plane_state;
> +
> +		plane_state = drm_atomic_get_plane_state(state, plane);
> +		if (IS_ERR(plane_state)) {
> +			ret = PTR_ERR(plane_state);
> +			goto fail;
> +		}
> +
> +		/* reset rotation: */

Comment is superflous imo. And we need to check for rotation_property here
like for the legacy path otherwise we'll blow up if that's not set up.

> +		ret = drm_atomic_plane_set_property(plane, plane_state,
> +				dev->mode_config.rotation_property,
> +				BIT(DRM_ROTATE_0));
> +		if (ret != 0)
> +			goto fail;
> +
> +		/* disable non-primary: */
> +		if (plane->type == DRM_PLANE_TYPE_PRIMARY)
> +			continue;
> +
> +		ret = __drm_atomic_helper_disable_plane(plane, plane_state);
> +		if (ret != 0)
> +			goto fail;
> +	}
> +
> +	for(i = 0; i < fb_helper->crtc_count; i++) {
> +		struct drm_mode_set *mode_set = &fb_helper->crtc_info[i].mode_set;
> +
> +		ret = __drm_atomic_helper_set_config(mode_set, state);
> +		if (ret != 0)
> +			goto fail;
> +	}
> +
> +	ret = drm_atomic_commit(state);
> +	if (ret != 0)
> +		goto fail;
> +
> +	return 0;
> +
> +fail:
> +	if (ret == -EDEADLK)
> +		goto backoff;
> +
> +	drm_atomic_state_free(state);
> +
> +	return ret;
> +
> +backoff:
> +	drm_atomic_state_clear(state);
> +	drm_atomic_legacy_backoff(state);
> +
> +	goto retry;
> +}
> +
>  static int restore_fbdev_mode(struct drm_fb_helper *fb_helper)
>  {
>  	struct drm_device *dev = fb_helper->dev;
> @@ -342,6 +411,9 @@ static int restore_fbdev_mode(struct drm_fb_helper *fb_helper)
>  
>  	drm_warn_on_modeset_not_all_locked(dev);
>  
> +	if (fb_helper->atomic)
> +		return restore_fbdev_mode_atomic(fb_helper);
> +
>  	drm_for_each_plane(plane, dev) {
>  		if (plane->type != DRM_PLANE_TYPE_PRIMARY)
>  			drm_plane_force_disable(plane);
> @@ -644,6 +716,8 @@ int drm_fb_helper_init(struct drm_device *dev,
>  		i++;
>  	}
>  
> +	fb_helper->atomic = !!drm_core_check_feature(dev, DRIVER_ATOMIC);
> +
>  	return 0;
>  out_free:
>  	drm_fb_helper_crtc_free(fb_helper);
> diff --git a/include/drm/drm_atomic_helper.h b/include/drm/drm_atomic_helper.h
> index 11266d14..88c0ef3 100644
> --- a/include/drm/drm_atomic_helper.h
> +++ b/include/drm/drm_atomic_helper.h
> @@ -30,6 +30,8 @@
>  
>  #include <drm/drm_crtc.h>
>  
> +struct drm_atomic_state;
> +
>  int drm_atomic_helper_check_modeset(struct drm_device *dev,
>  				struct drm_atomic_state *state);
>  int drm_atomic_helper_check_planes(struct drm_device *dev,
> @@ -72,7 +74,11 @@ int drm_atomic_helper_update_plane(struct drm_plane *plane,
>  				   uint32_t src_x, uint32_t src_y,
>  				   uint32_t src_w, uint32_t src_h);
>  int drm_atomic_helper_disable_plane(struct drm_plane *plane);
> +int __drm_atomic_helper_disable_plane(struct drm_plane *plane,
> +		struct drm_plane_state *plane_state);
>  int drm_atomic_helper_set_config(struct drm_mode_set *set);
> +int __drm_atomic_helper_set_config(struct drm_mode_set *set,
> +		struct drm_atomic_state *state);
>  
>  int drm_atomic_helper_crtc_set_property(struct drm_crtc *crtc,
>  					struct drm_property *property,
> diff --git a/include/drm/drm_fb_helper.h b/include/drm/drm_fb_helper.h
> index 6254136..cc3d820 100644
> --- a/include/drm/drm_fb_helper.h
> +++ b/include/drm/drm_fb_helper.h
> @@ -117,6 +117,12 @@ struct drm_fb_helper_connector {
>   * @pseudo_palette: fake palette of 16 colors
>   * @kernel_fb_list: list_head in kernel_fb_helper_list
>   * @delayed_hotplug: was there a hotplug while kms master active?
> + * @atomic: use atomic updates for restore_fbdev_mode(), etc.  This
> + *          defaults to true if driver has DRIVER_ATOMIC feature
> + *          flag, but drivers can override it to true after
> + *          drm_fb_helper_init() if they support atomic modeset
> + *          but do not yet advertise DRIVER_ATOMIC (note that
> + *          fb-helper does not require ASYNC commits).

New kerneldoc in 4.3 (already in linux-next and drm-intel-nightly) allows
you to push that right to the struct member, which is imo better for
longer explanations like this:

>   */
>  struct drm_fb_helper {
>  	struct drm_framebuffer *fb;
> @@ -134,6 +140,8 @@ struct drm_fb_helper {
>  	/* we got a hotplug but fbdev wasn't running the console
>  	   delay until next set_par */
>  	bool delayed_hotplug;

	/**
	 * @atomic:
	 *
	 * Use atomic updates for restore_fbdev_mode(), etc.  This defaults to
	 * true if driver has DRIVER_ATOMIC feature flag, but drivers can override
	 * it to true after drm_fb_helper_init() if they support atomic modeset
	 * but do not yet advertise DRIVER_ATOMIC (note that fb-helper does not
	 * require ASYNC commits).
	 */
	bool atomic;

Imo that looks prettier.
-Daniel

>  };
>  
>  #ifdef CONFIG_DRM_FBDEV_EMULATION
> -- 
> 2.4.3
> 

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
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dri-devel@lists.freedesktop.org
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Re: [PATCH 0/4] drm: atomic fb-helper support

[Daniel Vetter]

On Tue, Aug 25, 2015 at 12:35 PM, Rob Clark <robdclark@gmail.com> wrote:
> Convert fb-helper, or at least the two code-paths which potentially
> trigger more than a single update, to use atomic API if the driver
> supports it.
>
> The first patch is slightly unrelated, but I needed to add kerneldoc
> for 'struct drm_fb_helper' before I could add kerneldoc for the new
> atomic field.  Danvet tricked me into writing some kerneldoc that
> way.
>
> In theory, after this, we can re-introduce the ww_acquire_fini()
> call.
>
> Rob Clark (4):
>   drm/fb-helper: add headerdoc for drm_fb_helper
>   drm/fb-helper: atomic restore_fbdev_mode()..
>   drm/fb-helper: atomic pan_display()..
>   drm/i915: enable atomic fb-helper

Ok I applied the small comment bikesheds to patch 2 and merged all
four to drm-misc.

Thanks, Daniel

>  drivers/gpu/drm/drm_atomic_helper.c | 131 +++++++++++++++++++++---------------
>  drivers/gpu/drm/drm_fb_helper.c     | 131 ++++++++++++++++++++++++++++++++++++
>  drivers/gpu/drm/i915/intel_fbdev.c  |   2 +
>  include/drm/drm_atomic_helper.h     |   6 ++
>  include/drm/drm_fb_helper.h         |  22 ++++++
>  5 files changed, 239 insertions(+), 53 deletions(-)
>
> --
> 2.4.3
>



-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch
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dri-devel mailing list
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