From 955b4bf1a2fd2e6652980814983464f3db8f955f Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Jos=C3=A9=20Roberto=20de=20Souza?= Date: Fri, 1 Apr 2022 15:29:10 -0700 Subject: [PATCH] drm/i915/display/psr: Lock and unlock PSR around pipe updates MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Frontbuffer rendering and page flips can race with each other and this can potentialy cause issues with PSR2 selective fetch. And because pipe/crtc updates are time sentive we can't grab the PSR lock after intel_pipe_update_start() and before intel_pipe_update_end(). So here adding the lock and unlock functions and calls, the proper PSR2 selective fetch handling will come in a separated patch. Cc: Jouni Högander Cc: Mika Kahola Signed-off-by: José Roberto de Souza --- drivers/gpu/drm/i915/display/intel_crtc.c | 6 +- drivers/gpu/drm/i915/display/intel_psr.c | 69 ++++++++++++++++++++--- drivers/gpu/drm/i915/display/intel_psr.h | 5 +- 3 files changed, 70 insertions(+), 10 deletions(-) diff --git a/drivers/gpu/drm/i915/display/intel_crtc.c b/drivers/gpu/drm/i915/display/intel_crtc.c index f655c162287763..a5439182d5ae44 100644 --- a/drivers/gpu/drm/i915/display/intel_crtc.c +++ b/drivers/gpu/drm/i915/display/intel_crtc.c @@ -507,6 +507,8 @@ void intel_pipe_update_start(struct intel_crtc_state *new_crtc_state) VBLANK_EVASION_TIME_US); max = vblank_start - 1; + intel_psr_lock(new_crtc_state); + if (min <= 0 || max <= 0) goto irq_disable; @@ -518,7 +520,7 @@ void intel_pipe_update_start(struct intel_crtc_state *new_crtc_state) * VBL interrupts will start the PSR exit and prevent a PSR * re-entry as well. */ - intel_psr_wait_for_idle(new_crtc_state); + intel_psr_wait_for_idle_locked(new_crtc_state); local_irq_disable(); @@ -683,6 +685,8 @@ void intel_pipe_update_end(struct intel_crtc_state *new_crtc_state) local_irq_enable(); + intel_psr_unlock(new_crtc_state); + if (intel_vgpu_active(dev_priv)) return; diff --git a/drivers/gpu/drm/i915/display/intel_psr.c b/drivers/gpu/drm/i915/display/intel_psr.c index 2da2468f555ec5..58597480054ebd 100644 --- a/drivers/gpu/drm/i915/display/intel_psr.c +++ b/drivers/gpu/drm/i915/display/intel_psr.c @@ -1548,10 +1548,19 @@ void intel_psr2_program_plane_sel_fetch(struct intel_plane *plane, void intel_psr2_program_trans_man_trk_ctl(const struct intel_crtc_state *crtc_state) { struct drm_i915_private *dev_priv = to_i915(crtc_state->uapi.crtc->dev); + struct intel_encoder *encoder; if (!crtc_state->enable_psr2_sel_fetch) return; + for_each_intel_encoder_mask_with_psr(&dev_priv->drm, encoder, + crtc_state->uapi.encoder_mask) { + struct intel_dp *intel_dp = enc_to_intel_dp(encoder); + + lockdep_assert_held(&intel_dp->psr.lock); + break; + } + intel_de_write(dev_priv, PSR2_MAN_TRK_CTL(crtc_state->cpu_transcoder), crtc_state->psr2_man_track_ctl); } @@ -1919,13 +1928,13 @@ static int _psr1_ready_for_pipe_update_locked(struct intel_dp *intel_dp) } /** - * intel_psr_wait_for_idle - wait for PSR be ready for a pipe update + * intel_psr_wait_for_idle_locked - wait for PSR be ready for a pipe update * @new_crtc_state: new CRTC state * * This function is expected to be called from pipe_update_start() where it is * not expected to race with PSR enable or disable. */ -void intel_psr_wait_for_idle(const struct intel_crtc_state *new_crtc_state) +void intel_psr_wait_for_idle_locked(const struct intel_crtc_state *new_crtc_state) { struct drm_i915_private *dev_priv = to_i915(new_crtc_state->uapi.crtc->dev); struct intel_encoder *encoder; @@ -1938,12 +1947,10 @@ void intel_psr_wait_for_idle(const struct intel_crtc_state *new_crtc_state) struct intel_dp *intel_dp = enc_to_intel_dp(encoder); int ret; - mutex_lock(&intel_dp->psr.lock); + lockdep_assert_held(&intel_dp->psr.lock); - if (!intel_dp->psr.enabled) { - mutex_unlock(&intel_dp->psr.lock); + if (!intel_dp->psr.enabled) continue; - } if (intel_dp->psr.psr2_enabled) ret = _psr2_ready_for_pipe_update_locked(intel_dp); @@ -1952,8 +1959,6 @@ void intel_psr_wait_for_idle(const struct intel_crtc_state *new_crtc_state) if (ret) drm_err(&dev_priv->drm, "PSR wait timed out, atomic update may fail\n"); - - mutex_unlock(&intel_dp->psr.lock); } } @@ -2444,3 +2449,51 @@ bool intel_psr_enabled(struct intel_dp *intel_dp) return ret; } + +/** + * intel_psr_lock - grab psr.lock mutex + * @crtc_state: the crtc state + * + * This is initially meant to be used by around CRTC update, when + * vblank sensitive registers are updated and we need grab the lock + * before it to avoid vblank evasion. + */ +void intel_psr_lock(const struct intel_crtc_state *crtc_state) +{ + struct drm_i915_private *i915 = to_i915(crtc_state->uapi.crtc->dev); + struct intel_encoder *encoder; + + if (!crtc_state->has_psr) + return; + + for_each_intel_encoder_mask_with_psr(&i915->drm, encoder, + crtc_state->uapi.encoder_mask) { + struct intel_dp *intel_dp = enc_to_intel_dp(encoder); + + mutex_lock(&intel_dp->psr.lock); + break; + } +} + +/** + * intel_psr_lock - grab psr.lock mutex + * @crtc_state: the crtc state + * + * Release the PSR lock that was held during pipe update. + */ +void intel_psr_unlock(const struct intel_crtc_state *crtc_state) +{ + struct drm_i915_private *i915 = to_i915(crtc_state->uapi.crtc->dev); + struct intel_encoder *encoder; + + if (!crtc_state->has_psr) + return; + + for_each_intel_encoder_mask_with_psr(&i915->drm, encoder, + crtc_state->uapi.encoder_mask) { + struct intel_dp *intel_dp = enc_to_intel_dp(encoder); + + mutex_unlock(&intel_dp->psr.lock); + break; + } +} diff --git a/drivers/gpu/drm/i915/display/intel_psr.h b/drivers/gpu/drm/i915/display/intel_psr.h index f6526d9ccfdc6b..2ac3a46cccc50c 100644 --- a/drivers/gpu/drm/i915/display/intel_psr.h +++ b/drivers/gpu/drm/i915/display/intel_psr.h @@ -41,7 +41,7 @@ void intel_psr_get_config(struct intel_encoder *encoder, struct intel_crtc_state *pipe_config); void intel_psr_irq_handler(struct intel_dp *intel_dp, u32 psr_iir); void intel_psr_short_pulse(struct intel_dp *intel_dp); -void intel_psr_wait_for_idle(const struct intel_crtc_state *new_crtc_state); +void intel_psr_wait_for_idle_locked(const struct intel_crtc_state *new_crtc_state); bool intel_psr_enabled(struct intel_dp *intel_dp); int intel_psr2_sel_fetch_update(struct intel_atomic_state *state, struct intel_crtc *crtc); @@ -55,4 +55,7 @@ void intel_psr2_disable_plane_sel_fetch(struct intel_plane *plane, void intel_psr_pause(struct intel_dp *intel_dp); void intel_psr_resume(struct intel_dp *intel_dp); +void intel_psr_lock(const struct intel_crtc_state *crtc_state); +void intel_psr_unlock(const struct intel_crtc_state *crtc_state); + #endif /* __INTEL_PSR_H__ */