Re: [Intel-gfx] [PATCH v2 6/6] drm/atomic: Make async plane update checks work as intended, v2.
On 04.09.2017 13:48, Maarten Lankhorst wrote:
> By always keeping track of the last commit in plane_state, we know
> whether there is an active update on the plane or not. With that
> information we can reject the fast update, and force the slowpath
> to be used as was originally intended.
>
> We cannot use plane_state->crtc->state here, because this only mentions
> the most recent commit for the crtc, but not the planes that were part
> of it. We specifically care about what the last commit involving this
> plane is, which can only be tracked with a pointer in the plane state.
>
> Changes since v1:
> - Clean up the whole function here, instead of partially earlier.
> - Add mention in the commit message why we need commit in plane_state.
> - Swap plane->state in intel_legacy_cursor_update, instead of
> reassigning all variables. With this commit We know that the cursor
> is not part of any active commits so this hack can be removed.
>
> Cc: Gustavo Padovan
> Signed-off-by: Maarten Lankhorst
> Reviewed-by: Gustavo Padovan
> Reviewed-by: Daniel Vetter #v1
> ---
> drivers/gpu/drm/drm_atomic_helper.c | 53
> ++--
> drivers/gpu/drm/i915/intel_display.c | 27 +++---
> include/drm/drm_plane.h | 5 ++--
> 3 files changed, 35 insertions(+), 50 deletions(-)
>
> diff --git a/drivers/gpu/drm/drm_atomic_helper.c
> b/drivers/gpu/drm/drm_atomic_helper.c
> index c81d46927a74..a2cd432d8b2d 100644
> --- a/drivers/gpu/drm/drm_atomic_helper.c
> +++ b/drivers/gpu/drm/drm_atomic_helper.c
> @@ -1388,35 +1388,31 @@ int drm_atomic_helper_async_check(struct drm_device
> *dev,
> {
> struct drm_crtc *crtc;
> struct drm_crtc_state *crtc_state;
> - struct drm_crtc_commit *commit;
> - struct drm_plane *__plane, *plane = NULL;
> - struct drm_plane_state *__plane_state, *plane_state = NULL;
> + struct drm_plane *plane;
> + struct drm_plane_state *old_plane_state, *new_plane_state;
> const struct drm_plane_helper_funcs *funcs;
> - int i, j, n_planes = 0;
> + int i, n_planes = 0;
>
> for_each_new_crtc_in_state(state, crtc, crtc_state, i) {
> if (drm_atomic_crtc_needs_modeset(crtc_state))
> return -EINVAL;
> }
>
> - for_each_new_plane_in_state(state, __plane, __plane_state, i) {
> + for_each_oldnew_plane_in_state(state, plane, old_plane_state,
> new_plane_state, i)
> n_planes++;
> - plane = __plane;
> - plane_state = __plane_state;
> - }
>
> /* FIXME: we support only single plane updates for now */
> - if (!plane || n_planes != 1)
> + if (n_planes != 1)
> return -EINVAL;
>
> - if (!plane_state->crtc)
> + if (!new_plane_state->crtc)
> return -EINVAL;
>
Hello,
It looks like a NULL-checking of new_plane_state is missed here.
[ 70.138947] [] (drm_atomic_helper_async_check) from []
(drm_atomic_helper_check+0x4c/0x64)
[ 70.138958] [] (drm_atomic_helper_check) from []
(drm_atomic_check_only+0x2f4/0x56c)
[ 70.138969] [] (drm_atomic_check_only) from []
(drm_atomic_commit+0x10/0x50)
[ 70.138979] [] (drm_atomic_commit) from []
(drm_atomic_helper_update_plane+0xf0/0x100)
[ 70.138991] [] (drm_atomic_helper_update_plane) from []
(__setplane_internal+0x178/0x214)
[ 70.139003] [] (__setplane_internal) from []
(drm_mode_cursor_universal+0x118/0x1a8)
[ 70.139014] [] (drm_mode_cursor_universal) from []
(drm_mode_cursor_common+0x174/0x1ec)
[ 70.139026] [] (drm_mode_cursor_common) from []
(drm_mode_cursor_ioctl+0x58/0x60)
[ 70.139036] [] (drm_mode_cursor_ioctl) from []
(drm_ioctl+0x198/0x368)
[ 70.139047] [] (drm_ioctl) from []
(do_vfs_ioctl+0x9c/0x8f0)
[ 70.139058] [] (do_vfs_ioctl) from []
(SyS_ioctl+0x34/0x5c)
[ 70.139071] [] (SyS_ioctl) from []
(ret_fast_syscall+0x0/0x48)
It's triggered by Tegra DRM driver on Xorg's startup. I also should notice that
currently Tegra DRM doesn't have a working HW cursor, I'm going to send out
Tegra cursor patches sometime soon.
This variant works for me:
if (!new_plane_state || !new_plane_state->crtc)
return -EINVAL;
> funcs = plane->helper_private;
> if (!funcs->atomic_async_update)
> return -EINVAL;
>
> - if (plane_state->fence)
> + if (new_plane_state->fence)
> return -EINVAL;
>
> /*
> @@ -1424,31 +1420,11 @@ int drm_atomic_helper_async_check(struct drm_device
> *dev,
>* the plane. This prevents our async update's changes from getting
>* overridden by a previous synchronous update's state.
>*/
> - for_each_new_crtc_in_state(state, crtc, crtc_state, i) {
> - if (plane->crtc != crtc)
> - continue;
> -
> - spin_lock(&crtc->commit_lock);
> - commit = list_first_entry_or_null(&crtc->commit_list,
> - struct drm
[Intel-gfx] [PATCH v2 6/6] drm/atomic: Make async plane update checks work as intended, v2.
By always keeping track of the last commit in plane_state, we know
whether there is an active update on the plane or not. With that
information we can reject the fast update, and force the slowpath
to be used as was originally intended.
We cannot use plane_state->crtc->state here, because this only mentions
the most recent commit for the crtc, but not the planes that were part
of it. We specifically care about what the last commit involving this
plane is, which can only be tracked with a pointer in the plane state.
Changes since v1:
- Clean up the whole function here, instead of partially earlier.
- Add mention in the commit message why we need commit in plane_state.
- Swap plane->state in intel_legacy_cursor_update, instead of
reassigning all variables. With this commit We know that the cursor
is not part of any active commits so this hack can be removed.
Cc: Gustavo Padovan
Signed-off-by: Maarten Lankhorst
Reviewed-by: Gustavo Padovan
Reviewed-by: Daniel Vetter #v1
---
drivers/gpu/drm/drm_atomic_helper.c | 53 ++--
drivers/gpu/drm/i915/intel_display.c | 27 +++---
include/drm/drm_plane.h | 5 ++--
3 files changed, 35 insertions(+), 50 deletions(-)
diff --git a/drivers/gpu/drm/drm_atomic_helper.c
b/drivers/gpu/drm/drm_atomic_helper.c
index c81d46927a74..a2cd432d8b2d 100644
--- a/drivers/gpu/drm/drm_atomic_helper.c
+++ b/drivers/gpu/drm/drm_atomic_helper.c
@@ -1388,35 +1388,31 @@ int drm_atomic_helper_async_check(struct drm_device
*dev,
{
struct drm_crtc *crtc;
struct drm_crtc_state *crtc_state;
- struct drm_crtc_commit *commit;
- struct drm_plane *__plane, *plane = NULL;
- struct drm_plane_state *__plane_state, *plane_state = NULL;
+ struct drm_plane *plane;
+ struct drm_plane_state *old_plane_state, *new_plane_state;
const struct drm_plane_helper_funcs *funcs;
- int i, j, n_planes = 0;
+ int i, n_planes = 0;
for_each_new_crtc_in_state(state, crtc, crtc_state, i) {
if (drm_atomic_crtc_needs_modeset(crtc_state))
return -EINVAL;
}
- for_each_new_plane_in_state(state, __plane, __plane_state, i) {
+ for_each_oldnew_plane_in_state(state, plane, old_plane_state,
new_plane_state, i)
n_planes++;
- plane = __plane;
- plane_state = __plane_state;
- }
/* FIXME: we support only single plane updates for now */
- if (!plane || n_planes != 1)
+ if (n_planes != 1)
return -EINVAL;
- if (!plane_state->crtc)
+ if (!new_plane_state->crtc)
return -EINVAL;
funcs = plane->helper_private;
if (!funcs->atomic_async_update)
return -EINVAL;
- if (plane_state->fence)
+ if (new_plane_state->fence)
return -EINVAL;
/*
@@ -1424,31 +1420,11 @@ int drm_atomic_helper_async_check(struct drm_device
*dev,
* the plane. This prevents our async update's changes from getting
* overridden by a previous synchronous update's state.
*/
- for_each_new_crtc_in_state(state, crtc, crtc_state, i) {
- if (plane->crtc != crtc)
- continue;
-
- spin_lock(&crtc->commit_lock);
- commit = list_first_entry_or_null(&crtc->commit_list,
- struct drm_crtc_commit,
- commit_entry);
- if (!commit) {
- spin_unlock(&crtc->commit_lock);
- continue;
- }
- spin_unlock(&crtc->commit_lock);
-
- if (!crtc->state->state)
- continue;
+ if (old_plane_state->commit &&
+ !try_wait_for_completion(&old_plane_state->commit->hw_done))
+ return -EBUSY;
- for_each_plane_in_state(crtc->state->state, __plane,
- __plane_state, j) {
- if (__plane == plane)
- return -EINVAL;
- }
- }
-
- return funcs->atomic_async_check(plane, plane_state);
+ return funcs->atomic_async_check(plane, new_plane_state);
}
EXPORT_SYMBOL(drm_atomic_helper_async_check);
@@ -1814,9 +1790,10 @@ int drm_atomic_helper_setup_commit(struct
drm_atomic_state *state,
}
for_each_oldnew_plane_in_state(state, plane, old_plane_state,
new_plane_state, i) {
- /* commit tracked through new_crtc_state->commit, no need to do
it explicitly */
- if (new_plane_state->crtc)
- continue;
+ /*
+* Unlike connectors, always track planes explicitly for
+* async pageflip support.
+*/
/* Userspace is not allowed to get ahe
