From dea1731dfc25976e2046f71c03200aa3b642b34f Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Ville=20Syrj=C3=A4l=C3=A4?= Date: Wed, 13 Dec 2023 12:25:17 +0200 Subject: [PATCH] drm/i915: Move intel_vblank_evade() & co. into intel_vblank.c MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit intel_vblank.c seems like the appropriate place for the core vblank evasion code. Move it there. Signed-off-by: Ville Syrjälä Link: https://patchwork.freedesktop.org/patch/msgid/20231213102519.13500-8-ville.syrjala@linux.intel.com Reviewed-by: Uma Shankar --- 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,