> -----Original Message-----
> From: Intel-gfx <intel-gfx-boun...@lists.freedesktop.org> On Behalf Of Ville
> Syrjala
> Sent: Wednesday, December 13, 2023 3:55 PM
> To: intel-gfx@lists.freedesktop.org
> Subject: [PATCH 7/9] drm/i915: Move intel_vblank_evade() & co. into
> intel_vblank.c
>
> From: Ville Syrjälä <ville.syrj...@linux.intel.com>
>
> intel_vblank.c seems like the appropriate place for the core vblank evasion
> code.
> Move it there.
Looks Good to me.
Reviewed-by: Uma Shankar <uma.shan...@intel.com>
> Signed-off-by: Ville Syrjälä <ville.syrj...@linux.intel.com>
> ---
> drivers/gpu/drm/i915/display/intel_crtc.c | 135 --------------------
> drivers/gpu/drm/i915/display/intel_vblank.c | 130 +++++++++++++++++++
> drivers/gpu/drm/i915/display/intel_vblank.h | 12 ++
> 3 files changed, 142 insertions(+), 135 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_crtc.c
> b/drivers/gpu/drm/i915/display/intel_crtc.c
> index 11a6a4b0a258..25593f6aae7d 100644
> --- a/drivers/gpu/drm/i915/display/intel_crtc.c
> +++ b/drivers/gpu/drm/i915/display/intel_crtc.c
> @@ -461,141 +461,6 @@ int intel_usecs_to_scanlines(const struct
> drm_display_mode *adjusted_mode,
> 1000 * adjusted_mode->crtc_htotal); }
>
> -static int intel_mode_vblank_start(const struct drm_display_mode *mode) -{
> - int vblank_start = mode->crtc_vblank_start;
> -
> - if (mode->flags & DRM_MODE_FLAG_INTERLACE)
> - vblank_start = DIV_ROUND_UP(vblank_start, 2);
> -
> - return vblank_start;
> -}
> -
> -struct intel_vblank_evade_ctx {
> - struct intel_crtc *crtc;
> - int min, max, vblank_start;
> - bool need_vlv_dsi_wa;
> -};
> -
> -static void intel_vblank_evade_init(const struct intel_crtc_state
> *old_crtc_state,
> - const struct intel_crtc_state
> *new_crtc_state,
> - struct intel_vblank_evade_ctx *evade)
> -{
> - struct intel_crtc *crtc = to_intel_crtc(new_crtc_state->uapi.crtc);
> - struct drm_i915_private *i915 = to_i915(crtc->base.dev);
> - const struct intel_crtc_state *crtc_state;
> - const struct drm_display_mode *adjusted_mode;
> -
> - evade->crtc = crtc;
> -
> - evade->need_vlv_dsi_wa = (IS_VALLEYVIEW(i915) ||
> IS_CHERRYVIEW(i915)) &&
> - intel_crtc_has_type(new_crtc_state, INTEL_OUTPUT_DSI);
> -
> - /*
> - * During fastsets/etc. the transcoder is still
> - * running with the old timings at this point.
> - *
> - * TODO: maybe just use the active timings here?
> - */
> - if (intel_crtc_needs_modeset(new_crtc_state))
> - crtc_state = new_crtc_state;
> - else
> - crtc_state = old_crtc_state;
> -
> - adjusted_mode = &crtc_state->hw.adjusted_mode;
> -
> - if (crtc->mode_flags & I915_MODE_FLAG_VRR) {
> - /* timing changes should happen with VRR disabled */
> - drm_WARN_ON(crtc->base.dev,
> intel_crtc_needs_modeset(new_crtc_state) ||
> - new_crtc_state->update_m_n || new_crtc_state-
> >update_lrr);
> -
> - if (intel_vrr_is_push_sent(crtc_state))
> - evade->vblank_start =
> intel_vrr_vmin_vblank_start(crtc_state);
> - else
> - evade->vblank_start =
> intel_vrr_vmax_vblank_start(crtc_state);
> - } else {
> - evade->vblank_start =
> intel_mode_vblank_start(adjusted_mode);
> - }
> -
> - /* FIXME needs to be calibrated sensibly */
> - evade->min = evade->vblank_start -
> intel_usecs_to_scanlines(adjusted_mode,
> -
> VBLANK_EVASION_TIME_US);
> - evade->max = evade->vblank_start - 1;
> -
> - /*
> - * M/N and TRANS_VTOTAL are double buffered on the transcoder's
> - * undelayed vblank, so with seamless M/N and LRR we must evade
> - * both vblanks.
> - *
> - * DSB execution waits for the transcoder's undelayed vblank,
> - * hence we must kick off the commit before that.
> - */
> - if (new_crtc_state->dsb || new_crtc_state->update_m_n ||
> new_crtc_state->update_lrr)
> - evade->min -= adjusted_mode->crtc_vblank_start -
> adjusted_mode->crtc_vdisplay;
> -}
> -
> -/* must be called with vblank interrupt already enabled! */ -static int
> intel_vblank_evade(struct intel_vblank_evade_ctx *evade) -{
> - struct intel_crtc *crtc = evade->crtc;
> - struct drm_i915_private *i915 = to_i915(crtc->base.dev);
> - long timeout = msecs_to_jiffies_timeout(1);
> - wait_queue_head_t *wq = drm_crtc_vblank_waitqueue(&crtc->base);
> - DEFINE_WAIT(wait);
> - int scanline;
> -
> - if (evade->min <= 0 || evade->max <= 0)
> - return 0;
> -
> - for (;;) {
> - /*
> - * prepare_to_wait() has a memory barrier, which guarantees
> - * other CPUs can see the task state update by the time we
> - * read the scanline.
> - */
> - prepare_to_wait(wq, &wait, TASK_UNINTERRUPTIBLE);
> -
> - scanline = intel_get_crtc_scanline(crtc);
> - if (scanline < evade->min || scanline > evade->max)
> - break;
> -
> - if (!timeout) {
> - drm_err(&i915->drm,
> - "Potential atomic update failure on pipe %c\n",
> - pipe_name(crtc->pipe));
> - break;
> - }
> -
> - local_irq_enable();
> -
> - timeout = schedule_timeout(timeout);
> -
> - local_irq_disable();
> - }
> -
> - finish_wait(wq, &wait);
> -
> - /*
> - * On VLV/CHV DSI the scanline counter would appear to
> - * increment approx. 1/3 of a scanline before start of vblank.
> - * The registers still get latched at start of vblank however.
> - * This means we must not write any registers on the first
> - * line of vblank (since not the whole line is actually in
> - * vblank). And unfortunately we can't use the interrupt to
> - * wait here since it will fire too soon. We could use the
> - * frame start interrupt instead since it will fire after the
> - * critical scanline, but that would require more changes
> - * in the interrupt code. So for now we'll just do the nasty
> - * thing and poll for the bad scanline to pass us by.
> - *
> - * FIXME figure out if BXT+ DSI suffers from this as well
> - */
> - while (evade->need_vlv_dsi_wa && scanline == evade->vblank_start)
> - scanline = intel_get_crtc_scanline(crtc);
> -
> - return scanline;
> -}
> -
> /**
> * intel_pipe_update_start() - start update of a set of display registers
> * @state: the atomic state
> diff --git a/drivers/gpu/drm/i915/display/intel_vblank.c
> b/drivers/gpu/drm/i915/display/intel_vblank.c
> index fe256bf7b485..baf7354cb6e2 100644
> --- a/drivers/gpu/drm/i915/display/intel_vblank.c
> +++ b/drivers/gpu/drm/i915/display/intel_vblank.c
> @@ -5,6 +5,7 @@
>
> #include "i915_drv.h"
> #include "i915_reg.h"
> +#include "intel_crtc.h"
> #include "intel_de.h"
> #include "intel_display_types.h"
> #include "intel_vblank.h"
> @@ -581,3 +582,132 @@ void intel_crtc_update_active_timings(const struct
> intel_crtc_state *crtc_state,
> intel_vblank_section_exit(i915);
> spin_unlock_irqrestore(&i915->drm.vblank_time_lock, irqflags); }
> +
> +static int intel_mode_vblank_start(const struct drm_display_mode *mode)
> +{
> + int vblank_start = mode->crtc_vblank_start;
> +
> + if (mode->flags & DRM_MODE_FLAG_INTERLACE)
> + vblank_start = DIV_ROUND_UP(vblank_start, 2);
> +
> + return vblank_start;
> +}
> +
> +void intel_vblank_evade_init(const struct intel_crtc_state *old_crtc_state,
> + const struct intel_crtc_state *new_crtc_state,
> + struct intel_vblank_evade_ctx *evade) {
> + struct intel_crtc *crtc = to_intel_crtc(new_crtc_state->uapi.crtc);
> + struct drm_i915_private *i915 = to_i915(crtc->base.dev);
> + const struct intel_crtc_state *crtc_state;
> + const struct drm_display_mode *adjusted_mode;
> +
> + evade->crtc = crtc;
> +
> + evade->need_vlv_dsi_wa = (IS_VALLEYVIEW(i915) ||
> IS_CHERRYVIEW(i915)) &&
> + intel_crtc_has_type(new_crtc_state, INTEL_OUTPUT_DSI);
> +
> + /*
> + * During fastsets/etc. the transcoder is still
> + * running with the old timings at this point.
> + *
> + * TODO: maybe just use the active timings here?
> + */
> + if (intel_crtc_needs_modeset(new_crtc_state))
> + crtc_state = new_crtc_state;
> + else
> + crtc_state = old_crtc_state;
> +
> + adjusted_mode = &crtc_state->hw.adjusted_mode;
> +
> + if (crtc->mode_flags & I915_MODE_FLAG_VRR) {
> + /* timing changes should happen with VRR disabled */
> + drm_WARN_ON(crtc->base.dev,
> intel_crtc_needs_modeset(new_crtc_state) ||
> + new_crtc_state->update_m_n || new_crtc_state-
> >update_lrr);
> +
> + if (intel_vrr_is_push_sent(crtc_state))
> + evade->vblank_start =
> intel_vrr_vmin_vblank_start(crtc_state);
> + else
> + evade->vblank_start =
> intel_vrr_vmax_vblank_start(crtc_state);
> + } else {
> + evade->vblank_start =
> intel_mode_vblank_start(adjusted_mode);
> + }
> +
> + /* FIXME needs to be calibrated sensibly */
> + evade->min = evade->vblank_start -
> intel_usecs_to_scanlines(adjusted_mode,
> +
> VBLANK_EVASION_TIME_US);
> + evade->max = evade->vblank_start - 1;
> +
> + /*
> + * M/N and TRANS_VTOTAL are double buffered on the transcoder's
> + * undelayed vblank, so with seamless M/N and LRR we must evade
> + * both vblanks.
> + *
> + * DSB execution waits for the transcoder's undelayed vblank,
> + * hence we must kick off the commit before that.
> + */
> + if (new_crtc_state->dsb || new_crtc_state->update_m_n ||
> new_crtc_state->update_lrr)
> + evade->min -= adjusted_mode->crtc_vblank_start -
> +adjusted_mode->crtc_vdisplay; }
> +
> +/* must be called with vblank interrupt already enabled! */ int
> +intel_vblank_evade(struct intel_vblank_evade_ctx *evade) {
> + struct intel_crtc *crtc = evade->crtc;
> + struct drm_i915_private *i915 = to_i915(crtc->base.dev);
> + long timeout = msecs_to_jiffies_timeout(1);
> + wait_queue_head_t *wq = drm_crtc_vblank_waitqueue(&crtc->base);
> + DEFINE_WAIT(wait);
> + int scanline;
> +
> + if (evade->min <= 0 || evade->max <= 0)
> + return 0;
> +
> + for (;;) {
> + /*
> + * prepare_to_wait() has a memory barrier, which guarantees
> + * other CPUs can see the task state update by the time we
> + * read the scanline.
> + */
> + prepare_to_wait(wq, &wait, TASK_UNINTERRUPTIBLE);
> +
> + scanline = intel_get_crtc_scanline(crtc);
> + if (scanline < evade->min || scanline > evade->max)
> + break;
> +
> + if (!timeout) {
> + drm_err(&i915->drm,
> + "Potential atomic update failure on pipe %c\n",
> + pipe_name(crtc->pipe));
> + break;
> + }
> +
> + local_irq_enable();
> +
> + timeout = schedule_timeout(timeout);
> +
> + local_irq_disable();
> + }
> +
> + finish_wait(wq, &wait);
> +
> + /*
> + * On VLV/CHV DSI the scanline counter would appear to
> + * increment approx. 1/3 of a scanline before start of vblank.
> + * The registers still get latched at start of vblank however.
> + * This means we must not write any registers on the first
> + * line of vblank (since not the whole line is actually in
> + * vblank). And unfortunately we can't use the interrupt to
> + * wait here since it will fire too soon. We could use the
> + * frame start interrupt instead since it will fire after the
> + * critical scanline, but that would require more changes
> + * in the interrupt code. So for now we'll just do the nasty
> + * thing and poll for the bad scanline to pass us by.
> + *
> + * FIXME figure out if BXT+ DSI suffers from this as well
> + */
> + while (evade->need_vlv_dsi_wa && scanline == evade->vblank_start)
> + scanline = intel_get_crtc_scanline(crtc);
> +
> + return scanline;
> +}
> diff --git a/drivers/gpu/drm/i915/display/intel_vblank.h
> b/drivers/gpu/drm/i915/display/intel_vblank.h
> index 17636f140c71..ec6c3da3eeac 100644
> --- a/drivers/gpu/drm/i915/display/intel_vblank.h
> +++ b/drivers/gpu/drm/i915/display/intel_vblank.h
> @@ -13,6 +13,18 @@ struct drm_crtc;
> struct intel_crtc;
> struct intel_crtc_state;
>
> +struct intel_vblank_evade_ctx {
> + struct intel_crtc *crtc;
> + int min, max, vblank_start;
> + bool need_vlv_dsi_wa;
> +};
> +
> +void intel_vblank_evade_init(const struct intel_crtc_state *old_crtc_state,
> + const struct intel_crtc_state *new_crtc_state,
> + struct intel_vblank_evade_ctx *evade);
> +/* must be called with vblank interrupt already enabled! */ int
> +intel_vblank_evade(struct intel_vblank_evade_ctx *evade);
> +
> u32 i915_get_vblank_counter(struct drm_crtc *crtc);
> u32 g4x_get_vblank_counter(struct drm_crtc *crtc); bool
> intel_crtc_get_vblank_timestamp(struct drm_crtc *crtc, int *max_error,
> --
> 2.41.0
