From 3b3fdc52c31f828ff0fb71d2c6ce7bdcc64f20a1 Mon Sep 17 00:00:00 2001 From: Michael Olbrich Date: Wed, 22 Jun 2022 08:22:06 +0200 Subject: [PATCH] backend-drm: improve atomic commit failure handling When an atomic commit fails then the output will be stuck in REPAINT_AWAITING_COMPLETION state. It is waiting for a vblank event that was never scheduled. If the error is EBUSY then it can be expected to be a transient error. So propagate the error and schedule a new repaint in the core compositor. This is necessary because there are some circumstances when the commit can fail unexpectedly: - With 'state_invalid == true' one commit will disable all planes. If another commit for a different output is triggered immediately afterwards, then this commit can temporarily fail with EBUSY because it tries to use the same planes. - At least with i915, if one commit enables an output then a second commit for a different output immediately afterwards can temporarily fail with EBUSY. This is probably caused by some hardware interdependency. Signed-off-by: Michael Olbrich --- libweston/backend-drm/drm.c | 6 +++--- libweston/compositor.c | 26 +++++++++++++++++++++++--- 2 files changed, 26 insertions(+), 6 deletions(-) diff --git a/libweston/backend-drm/drm.c b/libweston/backend-drm/drm.c index c8bec7e4..79ab239d 100644 --- a/libweston/backend-drm/drm.c +++ b/libweston/backend-drm/drm.c @@ -593,8 +593,8 @@ drm_output_start_repaint_loop(struct weston_output *output_base) if (ret != 0) { weston_log("applying repaint-start state failed: %s\n", strerror(errno)); - if (ret == -EACCES) - return -1; + if (ret == -EACCES || ret == -EBUSY) + return ret; goto finish_frame; } @@ -657,7 +657,7 @@ drm_repaint_flush(struct weston_compositor *compositor) drm_debug(b, "[repaint] flushed pending_state %p\n", pending_state); device->repaint_data = NULL; - return (ret == -EACCES) ? -1 : 0; + return (ret == -EACCES || ret == -EBUSY) ? ret : 0; } /** diff --git a/libweston/compositor.c b/libweston/compositor.c index 89fe410e..9c1768d2 100644 --- a/libweston/compositor.c +++ b/libweston/compositor.c @@ -3405,6 +3405,20 @@ output_repaint_timer_arm(struct weston_compositor *compositor) wl_event_source_timer_update(compositor->repaint_timer, msec_to_next); } +static void +weston_output_schedule_repaint_restart(struct weston_output *output) +{ + assert(output->repaint_status == REPAINT_AWAITING_COMPLETION); + /* The device was busy so try again one frame later */ + timespec_add_nsec(&output->next_repaint, &output->next_repaint, + millihz_to_nsec(output->current_mode->refresh)); + output->repaint_status = REPAINT_SCHEDULED; + TL_POINT(output->compositor, "core_repaint_restart", + TLP_OUTPUT(output), TLP_END); + output_repaint_timer_arm(output->compositor); + weston_output_damage(output); +} + static int output_repaint_timer_handler(void *data) { @@ -3435,8 +3449,12 @@ output_repaint_timer_handler(void *data) if (ret != 0) { wl_list_for_each(output, &compositor->output_list, link) { - if (output->repainted) - weston_output_schedule_repaint_reset(output); + if (output->repainted) { + if (ret == -EBUSY) + weston_output_schedule_repaint_restart(output); + else + weston_output_schedule_repaint_reset(output); + } } } @@ -3583,7 +3601,9 @@ idle_repaint(void *data) output->repaint_status = REPAINT_AWAITING_COMPLETION; output->idle_repaint_source = NULL; ret = output->start_repaint_loop(output); - if (ret != 0) + if (ret == -EBUSY) + weston_output_schedule_repaint_restart(output); + else if (ret != 0) weston_output_schedule_repaint_reset(output); }