linux/drivers/gpu/drm/msm/msm_atomic.c
Daniel Vetter aef9dbb8f7 drm/atomic-helper: Add option to update planes only on active crtc
With drivers supporting runtime pm it's generally not a good idea to
touch the hardware when it's off. Add an option to the commit_planes
helper to support this case.

Note that the helpers already add all planes on a crtc when a modeset
happens, hence plane updates will not be lost if drivers set this to
true.

v2: Check for NULL state->crtc before chasing the pointer. Also check
both old and new crtc if there's a switch. Finally just outright
disallow switching crtcs for a plane if the plane is in active use, on
most hardware that doesn't make sense.

v3: Since commit_planes(active_only = true) is for enabling things
only after all the crtc are on we should only look at the new crtc to
decide whether to call the plane hooks - if the current CRTC isn't on
then skip. If the old crtc (when moving a plane) went down then the
plane should have been disabled as part of the pipe shutdown work
already. For which there's currently no helper really unfortunately.
Also move the check for wether a plane gets a new CRTC assigned while
still in active use out of this patch.

v4: Rebase over exynos changes.

Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Thierry Reding <treding@nvidia.com>
Cc: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Reviewed-by: Thierry Reding <treding@nvidia.com>
Tested-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
2015-09-08 13:49:08 +02:00

297 lines
7.6 KiB
C

/*
* Copyright (C) 2014 Red Hat
* Author: Rob Clark <robdclark@gmail.com>
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 as published by
* the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License along with
* this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include "msm_drv.h"
#include "msm_kms.h"
#include "msm_gem.h"
struct msm_commit {
struct drm_device *dev;
struct drm_atomic_state *state;
uint32_t fence;
struct msm_fence_cb fence_cb;
uint32_t crtc_mask;
};
static void fence_cb(struct msm_fence_cb *cb);
/* block until specified crtcs are no longer pending update, and
* atomically mark them as pending update
*/
static int start_atomic(struct msm_drm_private *priv, uint32_t crtc_mask)
{
int ret;
spin_lock(&priv->pending_crtcs_event.lock);
ret = wait_event_interruptible_locked(priv->pending_crtcs_event,
!(priv->pending_crtcs & crtc_mask));
if (ret == 0) {
DBG("start: %08x", crtc_mask);
priv->pending_crtcs |= crtc_mask;
}
spin_unlock(&priv->pending_crtcs_event.lock);
return ret;
}
/* clear specified crtcs (no longer pending update)
*/
static void end_atomic(struct msm_drm_private *priv, uint32_t crtc_mask)
{
spin_lock(&priv->pending_crtcs_event.lock);
DBG("end: %08x", crtc_mask);
priv->pending_crtcs &= ~crtc_mask;
wake_up_all_locked(&priv->pending_crtcs_event);
spin_unlock(&priv->pending_crtcs_event.lock);
}
static struct msm_commit *commit_init(struct drm_atomic_state *state)
{
struct msm_commit *c = kzalloc(sizeof(*c), GFP_KERNEL);
if (!c)
return NULL;
c->dev = state->dev;
c->state = state;
/* TODO we might need a way to indicate to run the cb on a
* different wq so wait_for_vblanks() doesn't block retiring
* bo's..
*/
INIT_FENCE_CB(&c->fence_cb, fence_cb);
return c;
}
static void commit_destroy(struct msm_commit *c)
{
end_atomic(c->dev->dev_private, c->crtc_mask);
kfree(c);
}
static void msm_atomic_wait_for_commit_done(struct drm_device *dev,
struct drm_atomic_state *old_state)
{
struct drm_crtc *crtc;
struct msm_drm_private *priv = old_state->dev->dev_private;
struct msm_kms *kms = priv->kms;
int ncrtcs = old_state->dev->mode_config.num_crtc;
int i;
for (i = 0; i < ncrtcs; i++) {
crtc = old_state->crtcs[i];
if (!crtc)
continue;
if (!crtc->state->enable)
continue;
/* Legacy cursor ioctls are completely unsynced, and userspace
* relies on that (by doing tons of cursor updates). */
if (old_state->legacy_cursor_update)
continue;
kms->funcs->wait_for_crtc_commit_done(kms, crtc);
}
}
/* The (potentially) asynchronous part of the commit. At this point
* nothing can fail short of armageddon.
*/
static void complete_commit(struct msm_commit *c)
{
struct drm_atomic_state *state = c->state;
struct drm_device *dev = state->dev;
struct msm_drm_private *priv = dev->dev_private;
struct msm_kms *kms = priv->kms;
kms->funcs->prepare_commit(kms, state);
drm_atomic_helper_commit_modeset_disables(dev, state);
drm_atomic_helper_commit_planes(dev, state, false);
drm_atomic_helper_commit_modeset_enables(dev, state);
/* NOTE: _wait_for_vblanks() only waits for vblank on
* enabled CRTCs. So we end up faulting when disabling
* due to (potentially) unref'ing the outgoing fb's
* before the vblank when the disable has latched.
*
* But if it did wait on disabled (or newly disabled)
* CRTCs, that would be racy (ie. we could have missed
* the irq. We need some way to poll for pipe shut
* down. Or just live with occasionally hitting the
* timeout in the CRTC disable path (which really should
* not be critical path)
*/
msm_atomic_wait_for_commit_done(dev, state);
drm_atomic_helper_cleanup_planes(dev, state);
kms->funcs->complete_commit(kms, state);
drm_atomic_state_free(state);
commit_destroy(c);
}
static void fence_cb(struct msm_fence_cb *cb)
{
struct msm_commit *c =
container_of(cb, struct msm_commit, fence_cb);
complete_commit(c);
}
static void add_fb(struct msm_commit *c, struct drm_framebuffer *fb)
{
struct drm_gem_object *obj = msm_framebuffer_bo(fb, 0);
c->fence = max(c->fence, msm_gem_fence(to_msm_bo(obj), MSM_PREP_READ));
}
int msm_atomic_check(struct drm_device *dev,
struct drm_atomic_state *state)
{
int ret;
/*
* msm ->atomic_check can update ->mode_changed for pixel format
* changes, hence must be run before we check the modeset changes.
*/
ret = drm_atomic_helper_check_planes(dev, state);
if (ret)
return ret;
ret = drm_atomic_helper_check_modeset(dev, state);
if (ret)
return ret;
return ret;
}
/**
* drm_atomic_helper_commit - commit validated state object
* @dev: DRM device
* @state: the driver state object
* @async: asynchronous commit
*
* This function commits a with drm_atomic_helper_check() pre-validated state
* object. This can still fail when e.g. the framebuffer reservation fails. For
* now this doesn't implement asynchronous commits.
*
* RETURNS
* Zero for success or -errno.
*/
int msm_atomic_commit(struct drm_device *dev,
struct drm_atomic_state *state, bool async)
{
int nplanes = dev->mode_config.num_total_plane;
int ncrtcs = dev->mode_config.num_crtc;
ktime_t timeout;
struct msm_commit *c;
int i, ret;
ret = drm_atomic_helper_prepare_planes(dev, state);
if (ret)
return ret;
c = commit_init(state);
if (!c) {
ret = -ENOMEM;
goto error;
}
/*
* Figure out what crtcs we have:
*/
for (i = 0; i < ncrtcs; i++) {
struct drm_crtc *crtc = state->crtcs[i];
if (!crtc)
continue;
c->crtc_mask |= (1 << drm_crtc_index(crtc));
}
/*
* Figure out what fence to wait for:
*/
for (i = 0; i < nplanes; i++) {
struct drm_plane *plane = state->planes[i];
struct drm_plane_state *new_state = state->plane_states[i];
if (!plane)
continue;
if ((plane->state->fb != new_state->fb) && new_state->fb)
add_fb(c, new_state->fb);
}
/*
* Wait for pending updates on any of the same crtc's and then
* mark our set of crtc's as busy:
*/
ret = start_atomic(dev->dev_private, c->crtc_mask);
if (ret) {
kfree(c);
goto error;
}
/*
* This is the point of no return - everything below never fails except
* when the hw goes bonghits. Which means we can commit the new state on
* the software side now.
*/
drm_atomic_helper_swap_state(dev, state);
/*
* Everything below can be run asynchronously without the need to grab
* any modeset locks at all under one conditions: It must be guaranteed
* that the asynchronous work has either been cancelled (if the driver
* supports it, which at least requires that the framebuffers get
* cleaned up with drm_atomic_helper_cleanup_planes()) or completed
* before the new state gets committed on the software side with
* drm_atomic_helper_swap_state().
*
* This scheme allows new atomic state updates to be prepared and
* checked in parallel to the asynchronous completion of the previous
* update. Which is important since compositors need to figure out the
* composition of the next frame right after having submitted the
* current layout.
*/
if (async) {
msm_queue_fence_cb(dev, &c->fence_cb, c->fence);
return 0;
}
timeout = ktime_add_ms(ktime_get(), 1000);
/* uninterruptible wait */
msm_wait_fence(dev, c->fence, &timeout, false);
complete_commit(c);
return 0;
error:
drm_atomic_helper_cleanup_planes(dev, state);
return ret;
}