by Sean Paul

[permalink] [raw]

Subject: Re: [PATCH 2/9] drm/msm/dpu: add real wait_for_commit_done()

On Tue, Aug 27, 2019 at 02:33:32PM -0700, Rob Clark wrote:
> From: Rob Clark <[email protected]>
>
> Just waiting for next vblank isn't ideal.. we should really be looking
> at the hw FLUSH register value to know if there is still an in-progress
> flush without stalling unnecessarily when there is no pending flush.
>
> Signed-off-by: Rob Clark <[email protected]>

Reviewed-by: Sean Paul <[email protected]>

> ---
> .../drm/msm/disp/dpu1/dpu_encoder_phys_vid.c | 22 ++++++++++++++++++-
> 1 file changed, 21 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_vid.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_vid.c
> index 737fe963a490..7c73b09894f0 100644
> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_vid.c
> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_vid.c
> @@ -526,6 +526,26 @@ static int dpu_encoder_phys_vid_wait_for_vblank(
> return _dpu_encoder_phys_vid_wait_for_vblank(phys_enc, true);
> }
>
> +static int dpu_encoder_phys_vid_wait_for_commit_done(
> + struct dpu_encoder_phys *phys_enc)
> +{
> + struct dpu_hw_ctl *hw_ctl = phys_enc->hw_ctl;
> + int ret;
> +
> + if (!hw_ctl)
> + return 0;
> +
> + ret = wait_event_timeout(phys_enc->pending_kickoff_wq,
> + (hw_ctl->ops.get_flush_register(hw_ctl) == 0),
> + msecs_to_jiffies(50));
> + if (ret <= 0) {
> + DPU_ERROR("vblank timeout\n");
> + return -ETIMEDOUT;
> + }
> +
> + return 0;
> +}
> +
> static void dpu_encoder_phys_vid_prepare_for_kickoff(
> struct dpu_encoder_phys *phys_enc)
> {
> @@ -676,7 +696,7 @@ static void dpu_encoder_phys_vid_init_ops(struct dpu_encoder_phys_ops *ops)
> ops->destroy = dpu_encoder_phys_vid_destroy;
> ops->get_hw_resources = dpu_encoder_phys_vid_get_hw_resources;
> ops->control_vblank_irq = dpu_encoder_phys_vid_control_vblank_irq;
> - ops->wait_for_commit_done = dpu_encoder_phys_vid_wait_for_vblank;
> + ops->wait_for_commit_done = dpu_encoder_phys_vid_wait_for_commit_done;
> ops->wait_for_vblank = dpu_encoder_phys_vid_wait_for_vblank;
> ops->wait_for_tx_complete = dpu_encoder_phys_vid_wait_for_vblank;
> ops->irq_control = dpu_encoder_phys_vid_irq_control;
> --
> 2.21.0
>

--
Sean Paul, Software Engineer, Google / Chromium OS

2019-08-29 13:08:05

by Sean Paul

[permalink] [raw]

Subject: Re: [PATCH 3/9] drm/msm/dpu: handle_frame_done() from vblank irq

On Tue, Aug 27, 2019 at 02:33:33PM -0700, Rob Clark wrote:
> From: Rob Clark <[email protected]>
>
> Previously the callback was called from whoever called wait_for_vblank(),
> but that isn't a great plan when wait_for_vblank() stops getting called,
> and results in frame_done_timer expiring.
>
> Signed-off-by: Rob Clark <[email protected]>

Reviewed-by: Sean Paul <[email protected]>

> ---
> drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c | 7 +-----
> .../drm/msm/disp/dpu1/dpu_encoder_phys_vid.c | 25 ++++++-------------
> 2 files changed, 9 insertions(+), 23 deletions(-)
>
> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c
> index c3f7154017c4..e7354aef9805 100644
> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c
> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c
> @@ -311,12 +311,7 @@ static void dpu_crtc_frame_event_work(struct kthread_work *work)
> | DPU_ENCODER_FRAME_EVENT_PANEL_DEAD)) {
>
> if (atomic_read(&dpu_crtc->frame_pending) < 1) {
> - /* this should not happen */
> - DRM_ERROR("crtc%d ev:%u ts:%lld frame_pending:%d\n",
> - crtc->base.id,
> - fevent->event,
> - ktime_to_ns(fevent->ts),
> - atomic_read(&dpu_crtc->frame_pending));
> + /* ignore vblank when not pending */
> } else if (atomic_dec_return(&dpu_crtc->frame_pending) == 0) {
> /* release bandwidth and other resources */
> trace_dpu_crtc_frame_event_done(DRMID(crtc),
> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_vid.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_vid.c
> index 7c73b09894f0..b9c84fb4d4a1 100644
> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_vid.c
> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_vid.c
> @@ -324,6 +324,10 @@ static void dpu_encoder_phys_vid_vblank_irq(void *arg, int irq_idx)
>
> /* Signal any waiting atomic commit thread */
> wake_up_all(&phys_enc->pending_kickoff_wq);
> +
> + phys_enc->parent_ops->handle_frame_done(phys_enc->parent, phys_enc,
> + DPU_ENCODER_FRAME_EVENT_DONE);
> +
> DPU_ATRACE_END("vblank_irq");
> }
>
> @@ -483,8 +487,8 @@ static void dpu_encoder_phys_vid_get_hw_resources(
> hw_res->intfs[phys_enc->intf_idx - INTF_0] = INTF_MODE_VIDEO;
> }
>
> -static int _dpu_encoder_phys_vid_wait_for_vblank(
> - struct dpu_encoder_phys *phys_enc, bool notify)
> +static int dpu_encoder_phys_vid_wait_for_vblank(
> + struct dpu_encoder_phys *phys_enc)
> {
> struct dpu_encoder_wait_info wait_info;
> int ret;
> @@ -499,10 +503,6 @@ static int _dpu_encoder_phys_vid_wait_for_vblank(
> wait_info.timeout_ms = KICKOFF_TIMEOUT_MS;
>
> if (!dpu_encoder_phys_vid_is_master(phys_enc)) {
> - if (notify && phys_enc->parent_ops->handle_frame_done)
> - phys_enc->parent_ops->handle_frame_done(
> - phys_enc->parent, phys_enc,
> - DPU_ENCODER_FRAME_EVENT_DONE);
> return 0;
> }
>
> @@ -512,20 +512,11 @@ static int _dpu_encoder_phys_vid_wait_for_vblank(
>
> if (ret == -ETIMEDOUT) {
> dpu_encoder_helper_report_irq_timeout(phys_enc, INTR_IDX_VSYNC);
> - } else if (!ret && notify && phys_enc->parent_ops->handle_frame_done)
> - phys_enc->parent_ops->handle_frame_done(
> - phys_enc->parent, phys_enc,
> - DPU_ENCODER_FRAME_EVENT_DONE);
> + }
>
> return ret;
> }
>
> -static int dpu_encoder_phys_vid_wait_for_vblank(
> - struct dpu_encoder_phys *phys_enc)
> -{
> - return _dpu_encoder_phys_vid_wait_for_vblank(phys_enc, true);
> -}
> -
> static int dpu_encoder_phys_vid_wait_for_commit_done(
> struct dpu_encoder_phys *phys_enc)
> {
> @@ -615,7 +606,7 @@ static void dpu_encoder_phys_vid_disable(struct dpu_encoder_phys *phys_enc)
> * scanout buffer) don't latch properly..
> */
> if (dpu_encoder_phys_vid_is_master(phys_enc)) {
> - ret = _dpu_encoder_phys_vid_wait_for_vblank(phys_enc, false);
> + ret = dpu_encoder_phys_vid_wait_for_vblank(phys_enc);
> if (ret) {
> atomic_set(&phys_enc->pending_kickoff_cnt, 0);
> DRM_ERROR("wait disable failed: id:%u intf:%d ret:%d\n",
> --
> 2.21.0
>

--
Sean Paul, Software Engineer, Google / Chromium OS