disp: msm: sde: avoid multiple frame-done encoder events

Currently there is a race condition in checking the
pending_kickoff_cnt in wr_ptr_irq wait from display-thread
and pp_done_irq from interrupt context. In both places,
pending_kickoff_cnt is read first and modified later. In
partial update cases where the frame-transfer is short,
such a race condition might happen and would lead to both
triggering the frame-done/release fence for the same frame.
Fix it by combining read/modify to one statement in both places.

Change-Id: I9162e7dc3f12af3590514f1ebfd68023aa920181
Signed-off-by: Veera Sundaram Sankaran <veeras@codeaurora.org>
This commit is contained in:
Veera Sundaram Sankaran
2019-05-30 14:14:49 -07:00
parent 5af1fe1891
commit b8b095b57d

View File

@@ -174,10 +174,7 @@ static void _sde_encoder_phys_cmd_update_intf_cfg(
static void sde_encoder_phys_cmd_pp_tx_done_irq(void *arg, int irq_idx) static void sde_encoder_phys_cmd_pp_tx_done_irq(void *arg, int irq_idx)
{ {
struct sde_encoder_phys *phys_enc = arg; struct sde_encoder_phys *phys_enc = arg;
unsigned long lock_flags; u32 event = 0;
int new_cnt;
u32 event = SDE_ENCODER_FRAME_EVENT_DONE |
SDE_ENCODER_FRAME_EVENT_SIGNAL_RELEASE_FENCE;
if (!phys_enc || !phys_enc->hw_pp) if (!phys_enc || !phys_enc->hw_pp)
return; return;
@@ -186,16 +183,15 @@ static void sde_encoder_phys_cmd_pp_tx_done_irq(void *arg, int irq_idx)
/* notify all synchronous clients first, then asynchronous clients */ /* notify all synchronous clients first, then asynchronous clients */
if (phys_enc->parent_ops.handle_frame_done && if (phys_enc->parent_ops.handle_frame_done &&
atomic_read(&phys_enc->pending_kickoff_cnt)) atomic_add_unless(&phys_enc->pending_kickoff_cnt, -1, 0)) {
event = SDE_ENCODER_FRAME_EVENT_DONE |
SDE_ENCODER_FRAME_EVENT_SIGNAL_RELEASE_FENCE;
phys_enc->parent_ops.handle_frame_done(phys_enc->parent, phys_enc->parent_ops.handle_frame_done(phys_enc->parent,
phys_enc, event); phys_enc, event);
}
spin_lock_irqsave(phys_enc->enc_spinlock, lock_flags);
new_cnt = atomic_add_unless(&phys_enc->pending_kickoff_cnt, -1, 0);
spin_unlock_irqrestore(phys_enc->enc_spinlock, lock_flags);
SDE_EVT32_IRQ(DRMID(phys_enc->parent), SDE_EVT32_IRQ(DRMID(phys_enc->parent),
phys_enc->hw_pp->idx - PINGPONG_0, new_cnt, event); phys_enc->hw_pp->idx - PINGPONG_0, event);
/* Signal any waiting atomic commit thread */ /* Signal any waiting atomic commit thread */
wake_up_all(&phys_enc->pending_kickoff_wq); wake_up_all(&phys_enc->pending_kickoff_wq);
@@ -1372,13 +1368,11 @@ static int _sde_encoder_phys_cmd_wait_for_wr_ptr(
SDE_ENCODER_FRAME_EVENT_SIGNAL_RETIRE_FENCE); SDE_ENCODER_FRAME_EVENT_SIGNAL_RETIRE_FENCE);
} else if ((ret == 0) && } else if ((ret == 0) &&
(phys_enc->frame_trigger_mode == FRAME_DONE_WAIT_POSTED_START) && (phys_enc->frame_trigger_mode == FRAME_DONE_WAIT_POSTED_START)
atomic_read(&phys_enc->pending_kickoff_cnt) && && ctl->ops.get_scheduler_status
ctl->ops.get_scheduler_status && && (ctl->ops.get_scheduler_status(ctl) & BIT(0))
(ctl->ops.get_scheduler_status(ctl) & BIT(0)) && && atomic_add_unless(&phys_enc->pending_kickoff_cnt, -1, 0)
phys_enc->parent_ops.handle_frame_done) { && phys_enc->parent_ops.handle_frame_done) {
atomic_add_unless(&phys_enc->pending_kickoff_cnt, -1, 0);
phys_enc->parent_ops.handle_frame_done( phys_enc->parent_ops.handle_frame_done(
phys_enc->parent, phys_enc, phys_enc->parent, phys_enc,
SDE_ENCODER_FRAME_EVENT_DONE | SDE_ENCODER_FRAME_EVENT_DONE |