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disp: msm: sde: manage vblank refcount concurrency

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Vblank refcount can reach out of sync with below case
 1. event_thread triggers the vblank_enable
 2. commit_thread triggers the modeset
   2.a modeset resets the vblank refcount with mode_set
 3. event_thread triggers the vblank_disable

Event 2.a resets the vblank refcount and vblank disable
request after 2.a is going to fail. This can be fixed
by avoiding concurrency between mode_set call and vblank
request.

Change-Id: Ibb810ec90e81d63feee443f1c37dd736d5cfac0d
Signed-off-by: Dhaval Patel <pdhaval@codeaurora.org>
This commit is contained in:
Dhaval Patel
2020-06-12 15:39:33 -07:00
committed by Gerrit - the friendly Code Review server
parent 743dc695c4
commit 44cde01fc7
5 changed files with 37 additions and 27 deletions
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50
msm/sde/sde_encoder_phys_cmd.c
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@@ -328,6 +328,7 @@ static void _sde_encoder_phys_cmd_setup_irq_hw_idx(
struct sde_encoder_irq *irq;
struct sde_kms *sde_kms;
int ret = 0;
u32 vblank_refcount;
if (!phys_enc->sde_kms || !phys_enc->hw_pp || !phys_enc->hw_ctl) {
SDE_ERROR("invalid args %d %d %d\n", !phys_enc->sde_kms,
@@ -342,20 +343,28 @@ static void _sde_encoder_phys_cmd_setup_irq_hw_idx(
sde_kms = phys_enc->sde_kms;
mutex_lock(&sde_kms->vblank_ctl_global_lock);
if (atomic_read(&phys_enc->vblank_refcount)) {
SDE_ERROR(
"vblank_refcount mismatch detected, try to reset %d\n",
atomic_read(&phys_enc->vblank_refcount));
mutex_lock(phys_enc->vblank_ctl_lock);
vblank_refcount = atomic_read(&phys_enc->vblank_refcount);
if (vblank_refcount) {
ret = sde_encoder_helper_unregister_irq(phys_enc,
INTR_IDX_RDPTR);
if (ret)
SDE_ERROR(
"control vblank irq registration error %d\n",
ret);
if (vblank_refcount > 1)
SDE_ERROR(
"vblank_refcount mismatch detected, try to reset %d\n",
atomic_read(&phys_enc->vblank_refcount));
else
atomic_set(&phys_enc->vblank_cached_refcount, 1);
SDE_EVT32(DRMID(phys_enc->parent),
phys_enc->hw_pp->idx - PINGPONG_0, vblank_refcount,
atomic_read(&phys_enc->vblank_cached_refcount));
}
atomic_set(&phys_enc->vblank_refcount, 0);
mutex_unlock(phys_enc->vblank_ctl_lock);
irq = &phys_enc->irq[INTR_IDX_CTL_START];
irq->hw_idx = phys_enc->hw_ctl->idx;
@@ -389,9 +398,6 @@ static void _sde_encoder_phys_cmd_setup_irq_hw_idx(
irq->hw_idx = phys_enc->hw_intf->idx;
else
irq->hw_idx = phys_enc->hw_pp->idx;
mutex_unlock(&sde_kms->vblank_ctl_global_lock);
}
static void sde_encoder_phys_cmd_cont_splash_mode_set(
@@ -811,7 +817,7 @@ static int sde_encoder_phys_cmd_control_vblank_irq(
struct sde_encoder_phys_cmd *cmd_enc =
to_sde_encoder_phys_cmd(phys_enc);
int ret = 0;
int refcount;
u32 refcount, cached_refcount;
struct sde_kms *sde_kms;
if (!phys_enc || !phys_enc->hw_pp) {
@@ -820,17 +826,23 @@ static int sde_encoder_phys_cmd_control_vblank_irq(
}
sde_kms = phys_enc->sde_kms;
mutex_lock(&sde_kms->vblank_ctl_global_lock);
refcount = atomic_read(&phys_enc->vblank_refcount);
mutex_lock(phys_enc->vblank_ctl_lock);
/* Slave encoders don't report vblank */
if (!sde_encoder_phys_cmd_is_master(phys_enc))
goto end;
refcount = atomic_read(&phys_enc->vblank_refcount);
cached_refcount = atomic_read(&phys_enc->vblank_cached_refcount);
/* protect against negative */
if (!enable && refcount == 0) {
ret = -EINVAL;
goto end;
if (cached_refcount == 1) {
atomic_set(&phys_enc->vblank_cached_refcount, 0);
goto end;
} else {
ret = -EINVAL;
goto end;
}
}
SDE_DEBUG_CMDENC(cmd_enc, "[%pS] enable=%d/%d\n",
@@ -850,7 +862,13 @@ static int sde_encoder_phys_cmd_control_vblank_irq(
atomic_inc_return(&phys_enc->vblank_refcount);
}
if (enable && cached_refcount) {
atomic_inc(&phys_enc->vblank_refcount);
atomic_set(&phys_enc->vblank_cached_refcount, 0);
}
end:
mutex_unlock(phys_enc->vblank_ctl_lock);
if (ret) {
SDE_ERROR_CMDENC(cmd_enc,
"control vblank irq error %d, enable %d, refcount %d\n",
@@ -860,7 +878,6 @@ end:
enable, refcount, SDE_EVTLOG_ERROR);
}
mutex_unlock(&sde_kms->vblank_ctl_global_lock);
return ret;
}
@@ -2068,6 +2085,7 @@ struct sde_encoder_phys *sde_encoder_phys_cmd_init(
irq->cb.func = sde_encoder_phys_cmd_wr_ptr_irq;
atomic_set(&phys_enc->vblank_refcount, 0);
atomic_set(&phys_enc->vblank_cached_refcount, 0);
atomic_set(&phys_enc->pending_kickoff_cnt, 0);
atomic_set(&phys_enc->pending_retire_fence_cnt, 0);
atomic_set(&cmd_enc->pending_vblank_cnt, 0);