Re: [PATCH v2 13/13] drm/i915/dsb: Add tracepoints for flip queue

["Borah, Chaitanya Kumar" <chaitanya.kumar.borah@intel.com>]

On 9/9/2026 9:47 PM, Ville Syrjala wrote:
> From: Ville Syrjälä <ville.syrjala@linux.intel.com>
> 
> Currently flip queue based commits don't leave any breadcrumbs
> via tracepoints. Add new intel_flipq_add and intel_flipq_done
> tracepoints that at least indicates when we something happens
> via the flip queeu.
> 
typo: queue

> We might want to improve this later somehow to have a slightly
> better idea what the flip queue might end up doing. But at least
> this now shows that *something* is going on.
> 

Reviewed-by: Chaitanya Kumar Borah <chaitanya.kumar.borah@intel.com>

> Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
> ---
>   .../drm/i915/display/intel_display_trace.h    | 60 +++++++++++++++++++
>   drivers/gpu/drm/i915/display/intel_dmc.c      |  3 +
>   drivers/gpu/drm/i915/display/intel_flipq.c    |  7 ++-
>   3 files changed, 69 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_display_trace.h b/drivers/gpu/drm/i915/display/intel_display_trace.h
> index 06cf662931fe..98ba7e20ca30 100644
> --- a/drivers/gpu/drm/i915/display/intel_display_trace.h
> +++ b/drivers/gpu/drm/i915/display/intel_display_trace.h
> @@ -23,6 +23,7 @@
>   #include "intel_display_limits.h"
>   #include "intel_display_types.h"
>   #include "intel_dsb.h"
> +#include "intel_flipq.h"
>   #include "intel_vblank.h"
>   
>   #define __dev_name_display(display) dev_name((display)->drm->dev)
> @@ -732,6 +733,65 @@ TRACE_EVENT(intel_dsb_done,
>   		      __entry->frame, __entry->scanline)
>   );
>   
> +TRACE_EVENT(intel_flipq_add,
> +	    TP_PROTO(struct intel_crtc *crtc,
> +		     enum intel_flipq_id flipq_id,
> +		     enum intel_dsb_id dsb_id,
> +		     u32 pts, u32 curr_pts),
> +	    TP_ARGS(crtc, flipq_id, dsb_id, pts, curr_pts),
> +
> +	    TP_STRUCT__entry(
> +			     __string(dev, __dev_name_kms(crtc))
> +			     __field(char, pipe_name)
> +			     __field(u32, flipq_id)
> +			     __field(u32, dsb_id)
> +			     __field(u32, pts)
> +			     __field(u32, curr_pts)
> +			     __field(u32, frame)
> +			     __field(u32, scanline)
> +			     ),
> +
> +	    TP_fast_assign(
> +			   __assign_str(dev);
> +			   __entry->pipe_name = pipe_name(crtc->pipe);
> +			   __entry->flipq_id = flipq_id;
> +			   __entry->dsb_id = dsb_id;
> +			   __entry->pts = pts;
> +			   __entry->curr_pts = curr_pts;
> +			   __entry->frame = intel_crtc_get_vblank_counter(crtc);
> +			   __entry->scanline = intel_get_crtc_scanline(crtc);
> +			   ),
> +
> +	    TP_printk("dev %s, pipe %c, FQ %d, DSB %d, PTS %u, current PTS %u, frame=%u, scanline=%u",
> +		      __get_str(dev), __entry->pipe_name,
> +		      __entry->flipq_id, __entry->dsb_id,
> +		      __entry->pts, __entry->curr_pts,
> +		      __entry->frame, __entry->scanline)
> +);
> +
> +TRACE_EVENT(intel_flipq_done,
> +	    TP_PROTO(struct intel_crtc *crtc),
> +	    TP_ARGS(crtc),
> +
> +	    TP_STRUCT__entry(
> +			     __string(dev, __dev_name_kms(crtc))
> +			     __field(char, pipe_name)
> +			     __field(u32, frame)
> +			     __field(u32, scanline)
> +			     ),
> +
> +	    TP_fast_assign(
> +			   __assign_str(dev);
> +			   __entry->pipe_name = pipe_name(crtc->pipe);
> +			   __entry->frame = intel_crtc_get_vblank_counter(crtc);
> +			   __entry->scanline = intel_get_crtc_scanline(crtc);
> +			   ),
> +
> +	    TP_printk("dev %s, pipe %c, frame=%u, scanline=%u",
> +		      __get_str(dev), __entry->pipe_name,
> +		      __entry->frame, __entry->scanline)
> +);
> +
>   TRACE_EVENT(intel_crtc_vblank_work_start,
>   	    TP_PROTO(struct intel_crtc *crtc),
>   	    TP_ARGS(crtc),
> diff --git a/drivers/gpu/drm/i915/display/intel_dmc.c b/drivers/gpu/drm/i915/display/intel_dmc.c
> index a191eee240d9..a16560f94986 100644
> --- a/drivers/gpu/drm/i915/display/intel_dmc.c
> +++ b/drivers/gpu/drm/i915/display/intel_dmc.c
> @@ -34,6 +34,7 @@
>   #include "intel_display_power_well.h"
>   #include "intel_display_regs.h"
>   #include "intel_display_rpm.h"
> +#include "intel_display_trace.h"
>   #include "intel_display_types.h"
>   #include "intel_display_utils.h"
>   #include "intel_dmc.h"
> @@ -1715,6 +1716,8 @@ void intel_pipedmc_irq_handler(struct intel_display *display, enum pipe pipe)
>   			spin_lock(&display->drm->event_lock);
>   
>   			if (crtc->flipq_event) {
> +				trace_intel_flipq_done(crtc);
> +
>   				/*
>   				 * Update vblank counter/timestamp in case it
>   				 * hasn't been done yet for this frame.
> diff --git a/drivers/gpu/drm/i915/display/intel_flipq.c b/drivers/gpu/drm/i915/display/intel_flipq.c
> index 45788234fc83..e7cfacd8a5ef 100644
> --- a/drivers/gpu/drm/i915/display/intel_flipq.c
> +++ b/drivers/gpu/drm/i915/display/intel_flipq.c
> @@ -11,6 +11,7 @@
>   #include "intel_crtc.h"
>   #include "intel_de.h"
>   #include "intel_display_core.h"
> +#include "intel_display_trace.h"
>   #include "intel_display_types.h"
>   #include "intel_display_utils.h"
>   #include "intel_display_wa.h"
> @@ -430,11 +431,13 @@ void intel_flipq_add(struct intel_crtc *crtc,
>   {
>   	struct intel_display *display = to_intel_display(crtc);
>   	struct intel_flipq *flipq = &crtc->flipq[flipq_id];
> +	unsigned int curr_pts;
>   
>   	if (!assert_flipq_has_room(crtc, flipq_id))
>   		return;
>   
> -	pts += intel_de_read(display, PIPEDMC_FPQ_TS(crtc->pipe));
> +	curr_pts = intel_de_read(display, PIPEDMC_FPQ_TS(crtc->pipe));
> +	pts += curr_pts;
>   
>   	intel_flipq_preempt(crtc, true);
>   
> @@ -446,6 +449,8 @@ void intel_flipq_add(struct intel_crtc *crtc,
>   	flipq->tail = (flipq->tail + 1) % intel_flipq_size_entries(flipq->flipq_id);
>   	intel_flipq_write_tail(crtc);
>   
> +	trace_intel_flipq_add(crtc, flipq_id, dsb_id, pts, curr_pts);
> +
>   	intel_flipq_preempt(crtc, false);
>   
>   	intel_flipq_sw_dmc_wake(crtc);