Hi Kieran,
Thank you for the patch.
On Saturday 04 Mar 2017 02:01:19 Kieran Bingham wrote:
> Currently we process page flip events on every display interrupt,
> however this does not take into consideration the processing time needed
> by the VSP1 utilised in the pipeline.
>
> Register a callback with the VSP driver to obtain completion events, and
> track them so that we only perform page flips when the full display
> pipeline has completed for the frame.
>
> Signed-off-by: Kieran Bingham <kieran.bingham+renesas@xxxxxxxxxxxxxxxx>
>
> ---
> v2:
> - Commit message completely re-worded for patch re-work.
> - drm_crtc_handle_vblank() re-instated in event of rcrtc->pending
> - removed passing of unnecessary 'data' through callbacks
> - perform page flips from the VSP completion handler
> - add locking around pending flags
>
> drivers/gpu/drm/rcar-du/rcar_du_crtc.c | 10 +++++++--
> drivers/gpu/drm/rcar-du/rcar_du_crtc.h | 2 ++-
> drivers/gpu/drm/rcar-du/rcar_du_vsp.c | 29 +++++++++++++++++++++++++++-
> 3 files changed, 39 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/rcar-du/rcar_du_crtc.c
> b/drivers/gpu/drm/rcar-du/rcar_du_crtc.c index 7391dd95c733..b7ff00bb45de
> 100644
> --- a/drivers/gpu/drm/rcar-du/rcar_du_crtc.c
> +++ b/drivers/gpu/drm/rcar-du/rcar_du_crtc.c
> @@ -299,7 +299,7 @@ static void rcar_du_crtc_update_planes(struct
> rcar_du_crtc *rcrtc) * Page Flip
> */
>
> -static void rcar_du_crtc_finish_page_flip(struct rcar_du_crtc *rcrtc)
> +void rcar_du_crtc_finish_page_flip(struct rcar_du_crtc *rcrtc)
> {
> struct drm_pending_vblank_event *event;
> struct drm_device *dev = rcrtc->crtc.dev;
> @@ -328,7 +328,7 @@ static bool rcar_du_crtc_page_flip_pending(struct
> rcar_du_crtc *rcrtc) bool pending;
>
> spin_lock_irqsave(&dev->event_lock, flags);
> - pending = rcrtc->event != NULL;
> + pending = (rcrtc->event != NULL) || (rcrtc->pending);
No need for parenthesis.
> spin_unlock_irqrestore(&dev->event_lock, flags);
>
> return pending;
> @@ -579,6 +579,12 @@ static irqreturn_t rcar_du_crtc_irq(int irq, void *arg)
>
> if (status & DSSR_FRM) {
> drm_crtc_handle_vblank(&rcrtc->crtc);
> +
> + if (rcrtc->pending) {
> + trace_printk("VBlank loss due to VSP Overrun\n");
> + return IRQ_HANDLED;
> + }
> +
More than that, now that the VSP completion handler finishes the page flip,
you should skip the rcar_du_crtc_finish_page_flip() call here unconditionally
on Gen3.
Something like
struct rcar_du_crtc *rcrtc = arg;
struct rcar_du_device *rcdu = rcrtc->group->dev;
...
if (status & DSSR_FRM) {
drm_crtc_handle_vblank(&rcrtc->crtc);
if (rcdu->info->gen < 3)
rcar_du_crtc_finish_page_flip(rcrtc);
ret = IRQ_HANDLED;
}
> rcar_du_crtc_finish_page_flip(rcrtc);
> ret = IRQ_HANDLED;
> }
> diff --git a/drivers/gpu/drm/rcar-du/rcar_du_crtc.h
> b/drivers/gpu/drm/rcar-du/rcar_du_crtc.h index a7194812997e..b73ec6de7af4
> 100644
> --- a/drivers/gpu/drm/rcar-du/rcar_du_crtc.h
> +++ b/drivers/gpu/drm/rcar-du/rcar_du_crtc.h
> @@ -47,6 +47,7 @@ struct rcar_du_crtc {
>
> struct drm_pending_vblank_event *event;
> wait_queue_head_t flip_wait;
> + bool pending;
>
> unsigned int outputs;
>
> @@ -71,5 +72,6 @@ void rcar_du_crtc_resume(struct rcar_du_crtc *rcrtc);
>
> void rcar_du_crtc_route_output(struct drm_crtc *crtc,
> enum rcar_du_output output);
> +void rcar_du_crtc_finish_page_flip(struct rcar_du_crtc *rcrtc);
>
> #endif /* __RCAR_DU_CRTC_H__ */
> diff --git a/drivers/gpu/drm/rcar-du/rcar_du_vsp.c
> b/drivers/gpu/drm/rcar-du/rcar_du_vsp.c index b0ff304ce3dc..1fcd311badb1
> 100644
> --- a/drivers/gpu/drm/rcar-du/rcar_du_vsp.c
> +++ b/drivers/gpu/drm/rcar-du/rcar_du_vsp.c
> @@ -28,6 +28,22 @@
> #include "rcar_du_kms.h"
> #include "rcar_du_vsp.h"
>
> +static void rcar_du_vsp_complete(void *private)
> +{
> + struct rcar_du_crtc *crtc = (struct rcar_du_crtc *)private;
> + struct drm_device *dev = crtc->crtc.dev;
> + unsigned long flags;
> + bool pending;
> +
> + spin_lock_irqsave(&dev->event_lock, flags);
> + pending = crtc->pending;
> + crtc->pending = false;
> + spin_unlock_irqrestore(&dev->event_lock, flags);
> +
> + if (pending)
> + rcar_du_crtc_finish_page_flip(crtc);
This seems to duplicate the synchronization mechanism based on events in
rcar_du_crtc_atomic_begin(). I need to check that in more details.
> +}
> +
> void rcar_du_vsp_enable(struct rcar_du_crtc *crtc)
> {
> const struct drm_display_mode *mode = &crtc->crtc.state-
>adjusted_mode;
> @@ -35,6 +51,8 @@ void rcar_du_vsp_enable(struct rcar_du_crtc *crtc)
> struct vsp1_du_lif_config cfg = {
> .width = mode->hdisplay,
> .height = mode->vdisplay,
> + .callback = rcar_du_vsp_complete,
> + .callback_data = crtc,
> };
> struct rcar_du_plane_state state = {
> .state = {
> @@ -85,6 +103,17 @@ void rcar_du_vsp_atomic_begin(struct rcar_du_crtc *crtc)
>
> void rcar_du_vsp_atomic_flush(struct rcar_du_crtc *crtc)
> {
> + struct drm_device *dev = crtc->crtc.dev;
> + unsigned long flags;
> + bool pending;
> +
> + spin_lock_irqsave(&dev->event_lock, flags);
> + pending = crtc->pending;
> + crtc->pending = true;
> + spin_unlock_irqrestore(&dev->event_lock, flags);
> +
> + WARN_ON(pending);
> +
> vsp1_du_atomic_flush(crtc->vsp->vsp);
> }
--
Regards,
Laurent Pinchart
