Re: [PATCH 8/9] drm/vc4: Add support for async pageflips.

[Daniel Stone]

Hi,

On 4 December 2015 at 01:42, Eric Anholt  wrote:
> Daniel Stone  writes:
>> On 1 December 2015 at 20:35, Eric Anholt  wrote:
>>> An async pageflip stores the modeset to be done and executes it once
>>> the BOs are ready to be displayed.  This gets us about 3x performance
>>> in full screen rendering with pageflipping.
>>
>> Looks good, but you're missing a preclose callback to reap dead events, a la:
>> https://git.collabora.com/cgit/user/daniels/linux.git/commit/?h=wip/4.4.x/rockchip-drm-fixes=d14f21bcd7e7a1b9ca129c411a9da9c911037965
>>
>> (and parent commit to wire that through to core DRM preclose)
>
> We've already got a preclose callback that reaps crtc->event -- see
> vc4_cancel_page_flip().

Right you are. Carry on then. :)

Cheers,
Daniel
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Re: [PATCH 8/9] drm/vc4: Add support for async pageflips.

[Daniel Stone]

Hi,

On 4 December 2015 at 01:42, Eric Anholt  wrote:
> Daniel Stone  writes:
>> On 1 December 2015 at 20:35, Eric Anholt  wrote:
>>> An async pageflip stores the modeset to be done and executes it once
>>> the BOs are ready to be displayed.  This gets us about 3x performance
>>> in full screen rendering with pageflipping.
>>
>> Looks good, but you're missing a preclose callback to reap dead events, a la:
>> https://git.collabora.com/cgit/user/daniels/linux.git/commit/?h=wip/4.4.x/rockchip-drm-fixes=d14f21bcd7e7a1b9ca129c411a9da9c911037965
>>
>> (and parent commit to wire that through to core DRM preclose)
>
> We've already got a preclose callback that reaps crtc->event -- see
> vc4_cancel_page_flip().

Right you are. Carry on then. :)

Cheers,
Daniel
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Re: [PATCH 8/9] drm/vc4: Add support for async pageflips.

[Eric Anholt]

Daniel Stone  writes:

> Hi,
>
> On 1 December 2015 at 20:35, Eric Anholt  wrote:
>> An async pageflip stores the modeset to be done and executes it once
>> the BOs are ready to be displayed.  This gets us about 3x performance
>> in full screen rendering with pageflipping.
>
> Looks good, but you're missing a preclose callback to reap dead events, a la:
> https://git.collabora.com/cgit/user/daniels/linux.git/commit/?h=wip/4.4.x/rockchip-drm-fixes=d14f21bcd7e7a1b9ca129c411a9da9c911037965
>
> (and parent commit to wire that through to core DRM preclose)

We've already got a preclose callback that reaps crtc->event -- see
vc4_cancel_page_flip().


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Re: [PATCH 8/9] drm/vc4: Add support for async pageflips.

[Eric Anholt]

Daniel Stone  writes:

> Hi,
>
> On 1 December 2015 at 20:35, Eric Anholt  wrote:
>> An async pageflip stores the modeset to be done and executes it once
>> the BOs are ready to be displayed.  This gets us about 3x performance
>> in full screen rendering with pageflipping.
>
> Looks good, but you're missing a preclose callback to reap dead events, a la:
> https://git.collabora.com/cgit/user/daniels/linux.git/commit/?h=wip/4.4.x/rockchip-drm-fixes=d14f21bcd7e7a1b9ca129c411a9da9c911037965
>
> (and parent commit to wire that through to core DRM preclose)

We've already got a preclose callback that reaps crtc->event -- see
vc4_cancel_page_flip().


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Description: PGP signature

Re: [PATCH 8/9] drm/vc4: Add support for async pageflips.

[Daniel Stone]

Hi,

On 1 December 2015 at 20:35, Eric Anholt  wrote:
> An async pageflip stores the modeset to be done and executes it once
> the BOs are ready to be displayed.  This gets us about 3x performance
> in full screen rendering with pageflipping.

Looks good, but you're missing a preclose callback to reap dead events, a la:
https://git.collabora.com/cgit/user/daniels/linux.git/commit/?h=wip/4.4.x/rockchip-drm-fixes=d14f21bcd7e7a1b9ca129c411a9da9c911037965

(and parent commit to wire that through to core DRM preclose)

Cheers,
Daniel
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Please read the FAQ at  http://www.tux.org/lkml/

Re: [PATCH 8/9] drm/vc4: Add support for async pageflips.

[Daniel Stone]

Hi,

On 1 December 2015 at 20:35, Eric Anholt  wrote:
> An async pageflip stores the modeset to be done and executes it once
> the BOs are ready to be displayed.  This gets us about 3x performance
> in full screen rendering with pageflipping.

Looks good, but you're missing a preclose callback to reap dead events, a la:
https://git.collabora.com/cgit/user/daniels/linux.git/commit/?h=wip/4.4.x/rockchip-drm-fixes=d14f21bcd7e7a1b9ca129c411a9da9c911037965

(and parent commit to wire that through to core DRM preclose)

Cheers,
Daniel
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
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Please read the FAQ at  http://www.tux.org/lkml/

[PATCH 8/9] drm/vc4: Add support for async pageflips.

[Eric Anholt]

An async pageflip stores the modeset to be done and executes it once
the BOs are ready to be displayed.  This gets us about 3x performance
in full screen rendering with pageflipping.

Signed-off-by: Eric Anholt 
---
 drivers/gpu/drm/vc4/vc4_crtc.c  |  99 +-
 drivers/gpu/drm/vc4/vc4_drv.h   |  16 +
 drivers/gpu/drm/vc4/vc4_gem.c   |  40 +++
 drivers/gpu/drm/vc4/vc4_kms.c   | 149 +++-
 drivers/gpu/drm/vc4/vc4_plane.c |  40 +++
 5 files changed, 342 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/vc4/vc4_crtc.c b/drivers/gpu/drm/vc4/vc4_crtc.c
index 7a9f476..a319332 100644
--- a/drivers/gpu/drm/vc4/vc4_crtc.c
+++ b/drivers/gpu/drm/vc4/vc4_crtc.c
@@ -35,6 +35,7 @@
 #include "drm_atomic_helper.h"
 #include "drm_crtc_helper.h"
 #include "linux/clk.h"
+#include "drm_fb_cma_helper.h"
 #include "linux/component.h"
 #include "linux/of_device.h"
 #include "vc4_drv.h"
@@ -475,10 +476,106 @@ static irqreturn_t vc4_crtc_irq_handler(int irq, void 
*data)
return ret;
 }
 
+struct vc4_async_flip_state {
+   struct drm_crtc *crtc;
+   struct drm_framebuffer *fb;
+   struct drm_pending_vblank_event *event;
+
+   struct vc4_seqno_cb cb;
+};
+
+/* Called when the V3D execution for the BO being flipped to is done, so that
+ * we can actually update the plane's address to point to it.
+ */
+static void
+vc4_async_page_flip_complete(struct vc4_seqno_cb *cb)
+{
+   struct vc4_async_flip_state *flip_state =
+   container_of(cb, struct vc4_async_flip_state, cb);
+   struct drm_crtc *crtc = flip_state->crtc;
+   struct drm_device *dev = crtc->dev;
+   struct vc4_dev *vc4 = to_vc4_dev(dev);
+   struct drm_plane *plane = crtc->primary;
+
+   vc4_plane_async_set_fb(plane, flip_state->fb);
+   if (flip_state->event) {
+   unsigned long flags;
+
+   spin_lock_irqsave(>event_lock, flags);
+   drm_crtc_send_vblank_event(crtc, flip_state->event);
+   spin_unlock_irqrestore(>event_lock, flags);
+   }
+
+   drm_framebuffer_unreference(flip_state->fb);
+   kfree(flip_state);
+
+   up(>async_modeset);
+}
+
+/* Implements async (non-vblank-synced) page flips.
+ *
+ * The page flip ioctl needs to return immediately, so we grab the
+ * modeset semaphore on the pipe, and queue the address update for
+ * when V3D is done with the BO being flipped to.
+ */
+static int vc4_async_page_flip(struct drm_crtc *crtc,
+  struct drm_framebuffer *fb,
+  struct drm_pending_vblank_event *event,
+  uint32_t flags)
+{
+   struct drm_device *dev = crtc->dev;
+   struct vc4_dev *vc4 = to_vc4_dev(dev);
+   struct drm_plane *plane = crtc->primary;
+   int ret = 0;
+   struct vc4_async_flip_state *flip_state;
+   struct drm_gem_cma_object *cma_bo = drm_fb_cma_get_gem_obj(fb, 0);
+   struct vc4_bo *bo = to_vc4_bo(_bo->base);
+
+   flip_state = kzalloc(sizeof(*flip_state), GFP_KERNEL);
+   if (!flip_state)
+   return -ENOMEM;
+
+   drm_framebuffer_reference(fb);
+   flip_state->fb = fb;
+   flip_state->crtc = crtc;
+   flip_state->event = event;
+
+   /* Make sure all other async modesetes have landed. */
+   ret = down_interruptible(>async_modeset);
+   if (ret) {
+   kfree(flip_state);
+   return ret;
+   }
+
+   /* Immediately update the plane's legacy fb pointer, so that later
+* modeset prep sees the state that will be present when the semaphore
+* is released.
+*/
+   drm_atomic_set_fb_for_plane(plane->state, fb);
+   plane->fb = fb;
+
+   vc4_queue_seqno_cb(dev, _state->cb, bo->seqno,
+  vc4_async_page_flip_complete);
+
+   /* Driver takes ownership of state on successful async commit. */
+   return 0;
+}
+
+static int vc4_page_flip(struct drm_crtc *crtc,
+struct drm_framebuffer *fb,
+struct drm_pending_vblank_event *event,
+uint32_t flags)
+{
+   if (flags & DRM_MODE_PAGE_FLIP_ASYNC)
+   return vc4_async_page_flip(crtc, fb, event, flags);
+   else
+   return drm_atomic_helper_page_flip(crtc, fb, event, flags);
+}
+
 static const struct drm_crtc_funcs vc4_crtc_funcs = {
.set_config = drm_atomic_helper_set_config,
.destroy = vc4_crtc_destroy,
-   .page_flip = drm_atomic_helper_page_flip,
+   .page_flip = vc4_page_flip,
.set_property = NULL,
.cursor_set = NULL, /* handled by drm_mode_cursor_universal */
.cursor_move = NULL, /* handled by drm_mode_cursor_universal */
diff --git a/drivers/gpu/drm/vc4/vc4_drv.h b/drivers/gpu/drm/vc4/vc4_drv.h
index a3dbfee..9a8ee23 100644
--- a/drivers/gpu/drm/vc4/vc4_drv.h
+++ b/drivers/gpu/drm/vc4/vc4_drv.h
@@ 

[PATCH 8/9] drm/vc4: Add support for async pageflips.

[Eric Anholt]

An async pageflip stores the modeset to be done and executes it once
the BOs are ready to be displayed.  This gets us about 3x performance
in full screen rendering with pageflipping.

Signed-off-by: Eric Anholt 
---
 drivers/gpu/drm/vc4/vc4_crtc.c  |  99 +-
 drivers/gpu/drm/vc4/vc4_drv.h   |  16 +
 drivers/gpu/drm/vc4/vc4_gem.c   |  40 +++
 drivers/gpu/drm/vc4/vc4_kms.c   | 149 +++-
 drivers/gpu/drm/vc4/vc4_plane.c |  40 +++
 5 files changed, 342 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/vc4/vc4_crtc.c b/drivers/gpu/drm/vc4/vc4_crtc.c
index 7a9f476..a319332 100644
--- a/drivers/gpu/drm/vc4/vc4_crtc.c
+++ b/drivers/gpu/drm/vc4/vc4_crtc.c
@@ -35,6 +35,7 @@
 #include "drm_atomic_helper.h"
 #include "drm_crtc_helper.h"
 #include "linux/clk.h"
+#include "drm_fb_cma_helper.h"
 #include "linux/component.h"
 #include "linux/of_device.h"
 #include "vc4_drv.h"
@@ -475,10 +476,106 @@ static irqreturn_t vc4_crtc_irq_handler(int irq, void 
*data)
return ret;
 }
 
+struct vc4_async_flip_state {
+   struct drm_crtc *crtc;
+   struct drm_framebuffer *fb;
+   struct drm_pending_vblank_event *event;
+
+   struct vc4_seqno_cb cb;
+};
+
+/* Called when the V3D execution for the BO being flipped to is done, so that
+ * we can actually update the plane's address to point to it.
+ */
+static void
+vc4_async_page_flip_complete(struct vc4_seqno_cb *cb)
+{
+   struct vc4_async_flip_state *flip_state =
+   container_of(cb, struct vc4_async_flip_state, cb);
+   struct drm_crtc *crtc = flip_state->crtc;
+   struct drm_device *dev = crtc->dev;
+   struct vc4_dev *vc4 = to_vc4_dev(dev);
+   struct drm_plane *plane = crtc->primary;
+
+   vc4_plane_async_set_fb(plane, flip_state->fb);
+   if (flip_state->event) {
+   unsigned long flags;
+
+   spin_lock_irqsave(>event_lock, flags);
+   drm_crtc_send_vblank_event(crtc, flip_state->event);
+   spin_unlock_irqrestore(>event_lock, flags);
+   }
+
+   drm_framebuffer_unreference(flip_state->fb);
+   kfree(flip_state);
+
+   up(>async_modeset);
+}
+
+/* Implements async (non-vblank-synced) page flips.
+ *
+ * The page flip ioctl needs to return immediately, so we grab the
+ * modeset semaphore on the pipe, and queue the address update for
+ * when V3D is done with the BO being flipped to.
+ */
+static int vc4_async_page_flip(struct drm_crtc *crtc,
+  struct drm_framebuffer *fb,
+  struct drm_pending_vblank_event *event,
+  uint32_t flags)
+{
+   struct drm_device *dev = crtc->dev;
+   struct vc4_dev *vc4 = to_vc4_dev(dev);
+   struct drm_plane *plane = crtc->primary;
+   int ret = 0;
+   struct vc4_async_flip_state *flip_state;
+   struct drm_gem_cma_object *cma_bo = drm_fb_cma_get_gem_obj(fb, 0);
+   struct vc4_bo *bo = to_vc4_bo(_bo->base);
+
+   flip_state = kzalloc(sizeof(*flip_state), GFP_KERNEL);
+   if (!flip_state)
+   return -ENOMEM;
+
+   drm_framebuffer_reference(fb);
+   flip_state->fb = fb;
+   flip_state->crtc = crtc;
+   flip_state->event = event;
+
+   /* Make sure all other async modesetes have landed. */
+   ret = down_interruptible(>async_modeset);
+   if (ret) {
+   kfree(flip_state);
+   return ret;
+   }
+
+   /* Immediately update the plane's legacy fb pointer, so that later
+* modeset prep sees the state that will be present when the semaphore
+* is released.
+*/
+   drm_atomic_set_fb_for_plane(plane->state, fb);
+   plane->fb = fb;
+
+   vc4_queue_seqno_cb(dev, _state->cb, bo->seqno,
+  vc4_async_page_flip_complete);
+
+   /* Driver takes ownership of state on successful async commit. */
+   return 0;
+}
+
+static int vc4_page_flip(struct drm_crtc *crtc,
+struct drm_framebuffer *fb,
+struct drm_pending_vblank_event *event,
+uint32_t flags)
+{
+   if (flags & DRM_MODE_PAGE_FLIP_ASYNC)
+   return vc4_async_page_flip(crtc, fb, event, flags);
+   else
+   return drm_atomic_helper_page_flip(crtc, fb, event, flags);
+}
+
 static const struct drm_crtc_funcs vc4_crtc_funcs = {
.set_config = drm_atomic_helper_set_config,
.destroy = vc4_crtc_destroy,
-   .page_flip = drm_atomic_helper_page_flip,
+   .page_flip = vc4_page_flip,
.set_property = NULL,
.cursor_set = NULL, /* handled by drm_mode_cursor_universal */
.cursor_move = NULL, /* handled by drm_mode_cursor_universal */
diff --git a/drivers/gpu/drm/vc4/vc4_drv.h b/drivers/gpu/drm/vc4/vc4_drv.h
index a3dbfee..9a8ee23 100644
--- a/drivers/gpu/drm/vc4/vc4_drv.h
+++