diff options
| author | Rob Clark <robdclark@chromium.org> | 2019-11-04 20:37:36 +0300 |
|---|---|---|
| committer | Sean Paul <seanpaul@chromium.org> | 2019-11-06 21:00:21 +0300 |
| commit | 86de88cfeb7cf33c7bbd18360e041c7d4e651bba (patch) | |
| tree | e68b05d9f67df3c30ca92c041ba7cdea649bbab6 /drivers/gpu/drm/drm_atomic_helper.c | |
| parent | b330f3972f4f2a829d41fb9e9b552bec7d73a840 (diff) | |
| download | linux-86de88cfeb7cf33c7bbd18360e041c7d4e651bba.tar.xz | |
drm/atomic: fix self-refresh helpers crtc state dereference
drm_self_refresh_helper_update_avg_times() was incorrectly accessing the
new incoming state after drm_atomic_helper_commit_hw_done(). But this
state might have already been superceeded by an !nonblock atomic update
resulting in dereferencing an already free'd crtc_state.
TODO I *think* this will more or less do the right thing.. althought I'm
not 100% sure if, for example, we enter psr in a nonblock commit, and
then leave psr in a !nonblock commit that overtakes the completion of
the nonblock commit. Not sure if this sort of scenario can happen in
practice. But not crashing is better than crashing, so I guess we
should either take this patch or rever the self-refresh helpers until
Sean can figure out a better solution.
Fixes: d4da4e33341c ("drm: Measure Self Refresh Entry/Exit times to avoid thrashing")
Cc: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Rob Clark <robdclark@chromium.org>
[seanpaul fixed up some checkpatch warns]
Signed-off-by: Sean Paul <seanpaul@chromium.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20191104173737.142558-1-robdclark@gmail.com
Diffstat (limited to 'drivers/gpu/drm/drm_atomic_helper.c')
| -rw-r--r-- | drivers/gpu/drm/drm_atomic_helper.c | 15 |
1 files changed, 14 insertions, 1 deletions
diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c index 3ef2ac52ce94..2dd2cd87cdbb 100644 --- a/drivers/gpu/drm/drm_atomic_helper.c +++ b/drivers/gpu/drm/drm_atomic_helper.c @@ -1581,8 +1581,11 @@ static void commit_tail(struct drm_atomic_state *old_state) { struct drm_device *dev = old_state->dev; const struct drm_mode_config_helper_funcs *funcs; + struct drm_crtc_state *new_crtc_state; + struct drm_crtc *crtc; ktime_t start; s64 commit_time_ms; + unsigned int i, new_self_refresh_mask = 0; funcs = dev->mode_config.helper_private; @@ -1602,6 +1605,15 @@ static void commit_tail(struct drm_atomic_state *old_state) drm_atomic_helper_wait_for_dependencies(old_state); + /* + * We cannot safely access new_crtc_state after + * drm_atomic_helper_commit_hw_done() so figure out which crtc's have + * self-refresh active beforehand: + */ + for_each_new_crtc_in_state(old_state, crtc, new_crtc_state, i) + if (new_crtc_state->self_refresh_active) + new_self_refresh_mask |= BIT(i); + if (funcs && funcs->atomic_commit_tail) funcs->atomic_commit_tail(old_state); else @@ -1610,7 +1622,8 @@ static void commit_tail(struct drm_atomic_state *old_state) commit_time_ms = ktime_ms_delta(ktime_get(), start); if (commit_time_ms > 0) drm_self_refresh_helper_update_avg_times(old_state, - (unsigned long)commit_time_ms); + (unsigned long)commit_time_ms, + new_self_refresh_mask); drm_atomic_helper_commit_cleanup_done(old_state); |