[PATCH v2 09/11] drm/i915/psr: Apply underrun on PSR idle workaround

Kahola, Mika mika.kahola at intel.com
Tue Apr 8 12:27:14 UTC 2025


> -----Original Message-----
> From: Intel-gfx <intel-gfx-bounces at lists.freedesktop.org> On Behalf Of Jouni
> Högander
> Sent: Monday, 17 March 2025 10.19
> To: intel-gfx at lists.freedesktop.org; intel-xe at lists.freedesktop.org
> Cc: Hogander, Jouni <jouni.hogander at intel.com>
> Subject: [PATCH v2 09/11] drm/i915/psr: Apply underrun on PSR idle workaround
> 
> This patch is applying workaround for underrun on idle PSR HW issue
> (Wa_16025596647) when PSR is getting enabled. It uses vblank enable/disable
> status, DC5/6 enabled disabled and enabled pipes count information made
> available.
> 
> This patch is also adding calls to dc5/dc6, vblank enable/disable and pipe
> enable/disable notification functions as needed.
> intel_psr_needs_block_dc_vblank is modified to get vblank enable/disable
> notification on PSR capable system.
> 
> Bspec: 74151
> 

Reviewed-by: Mika Kahola <mika.kahola at intel.com>

> Signed-off-by: Jouni Högander <jouni.hogander at intel.com>
> ---
>  drivers/gpu/drm/i915/display/intel_display.c  |   4 +
>  .../drm/i915/display/intel_display_driver.c   |   3 +
>  .../gpu/drm/i915/display/intel_display_irq.c  |   9 +-
>  .../i915/display/intel_display_power_well.c   |   4 +
>  drivers/gpu/drm/i915/display/intel_psr.c      | 103 +++++++++++-------
>  5 files changed, 76 insertions(+), 47 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_display.c
> b/drivers/gpu/drm/i915/display/intel_display.c
> index 3afb85fe8536d..834d023d0c626 100644
> --- a/drivers/gpu/drm/i915/display/intel_display.c
> +++ b/drivers/gpu/drm/i915/display/intel_display.c
> @@ -6648,6 +6648,8 @@ static void intel_enable_crtc(struct intel_atomic_state
> *state,
>  		intel_crtc_update_active_timings(pipe_crtc_state, false);
>  	}
> 
> +	intel_psr_notify_pipe_change(state, crtc, true);
> +
>  	display->funcs.display->crtc_enable(state, crtc);
> 
>  	/* vblanks work again, re-enable pipe CRC. */ @@ -6767,6 +6769,8 @@
> static void intel_old_crtc_state_disables(struct intel_atomic_state *state,
> 
> intel_crtc_joined_pipe_mask(old_crtc_state))
>  		intel_crtc_disable_pipe_crc(pipe_crtc);
> 
> +	intel_psr_notify_pipe_change(state, crtc, false);
> +
>  	display->funcs.display->crtc_disable(state, crtc);
> 
>  	for_each_intel_crtc_in_pipe_mask(display->drm, pipe_crtc, diff --git
> a/drivers/gpu/drm/i915/display/intel_display_driver.c
> b/drivers/gpu/drm/i915/display/intel_display_driver.c
> index 31740a677dd80..b4c989bbac93a 100644
> --- a/drivers/gpu/drm/i915/display/intel_display_driver.c
> +++ b/drivers/gpu/drm/i915/display/intel_display_driver.c
> @@ -54,6 +54,7 @@
>  #include "intel_plane_initial.h"
>  #include "intel_pmdemand.h"
>  #include "intel_pps.h"
> +#include "intel_psr.h"
>  #include "intel_quirks.h"
>  #include "intel_vga.h"
>  #include "intel_wm.h"
> @@ -226,6 +227,8 @@ int intel_display_driver_probe_noirq(struct intel_display
> *display)
>  	if (ret)
>  		goto cleanup_bios;
> 
> +	intel_psr_dc5_dc6_wa_init(display);
> +
>  	/* FIXME: completely on the wrong abstraction layer */
>  	ret = intel_power_domains_init(display);
>  	if (ret < 0)
> diff --git a/drivers/gpu/drm/i915/display/intel_display_irq.c
> b/drivers/gpu/drm/i915/display/intel_display_irq.c
> index aa23bb8178053..62fbdcbb4a123 100644
> --- a/drivers/gpu/drm/i915/display/intel_display_irq.c
> +++ b/drivers/gpu/drm/i915/display/intel_display_irq.c
> @@ -1728,14 +1728,7 @@ static void intel_display_vblank_dc_work(struct
> work_struct *work)
>  		container_of(work, typeof(*display), irq.vblank_dc_work);
>  	int vblank_wa_num_pipes = READ_ONCE(display-
> >irq.vblank_wa_num_pipes);
> 
> -	/*
> -	 * NOTE: intel_display_power_set_target_dc_state is used only by PSR
> -	 * code for DC3CO handling. DC3CO target state is currently disabled in
> -	 * PSR code. If DC3CO is taken into use we need take that into account
> -	 * here as well.
> -	 */
> -	intel_display_power_set_target_dc_state(display, vblank_wa_num_pipes
> ? DC_STATE_DISABLE :
> -						DC_STATE_EN_UPTO_DC6);
> +	intel_psr_notify_vblank_enable_disable(display, vblank_wa_num_pipes);
>  }
> 
>  int bdw_enable_vblank(struct drm_crtc *_crtc) diff --git
> a/drivers/gpu/drm/i915/display/intel_display_power_well.c
> b/drivers/gpu/drm/i915/display/intel_display_power_well.c
> index 8ec87ffd87d26..510f97341893b 100644
> --- a/drivers/gpu/drm/i915/display/intel_display_power_well.c
> +++ b/drivers/gpu/drm/i915/display/intel_display_power_well.c
> @@ -24,6 +24,7 @@
>  #include "intel_hotplug.h"
>  #include "intel_pcode.h"
>  #include "intel_pps.h"
> +#include "intel_psr.h"
>  #include "intel_tc.h"
>  #include "intel_vga.h"
>  #include "skl_watermark.h"
> @@ -762,6 +763,9 @@ void gen9_set_dc_state(struct intel_display *display, u32
> state)
>  			     state & ~power_domains->allowed_dc_mask))
>  		state &= power_domains->allowed_dc_mask;
> 
> +	if (!power_domains->initializing)
> +		intel_psr_notify_dc5_dc6(display);
> +
>  	val = intel_de_read(display, DC_STATE_EN);
>  	mask = gen9_dc_mask(display);
>  	drm_dbg_kms(display->drm, "Setting DC state from %02x to %02x\n", diff
> --git a/drivers/gpu/drm/i915/display/intel_psr.c
> b/drivers/gpu/drm/i915/display/intel_psr.c
> index afb9faed7784b..d2a28a83e4f20 100644
> --- a/drivers/gpu/drm/i915/display/intel_psr.c
> +++ b/drivers/gpu/drm/i915/display/intel_psr.c
> @@ -908,6 +908,41 @@ static u8 psr_compute_idle_frames(struct intel_dp
> *intel_dp)
>  	return idle_frames;
>  }
> 
> +/* Wa_16025596647 */
> +static void psr1_apply_underrun_on_idle_wa_locked(struct intel_dp *intel_dp,
> +						  bool dc5_dc6_blocked)
> +{
> +	struct intel_display *display = to_intel_display(intel_dp);
> +	u32 val;
> +
> +	if (dc5_dc6_blocked)
> +		val = DMC_EVT_CTL_ENABLE | DMC_EVT_CTL_RECURRING |
> +			REG_FIELD_PREP(DMC_EVT_CTL_TYPE_MASK,
> +				       DMC_EVT_CTL_TYPE_EDGE_0_1) |
> +			REG_FIELD_PREP(DMC_EVT_CTL_EVENT_ID_MASK,
> +				       DMC_EVT_CTL_EVENT_ID_VBLANK_A);
> +	else
> +		val = REG_FIELD_PREP(DMC_EVT_CTL_EVENT_ID_MASK,
> +				     DMC_EVT_CTL_EVENT_ID_FALSE) |
> +			REG_FIELD_PREP(DMC_EVT_CTL_TYPE_MASK,
> +				       DMC_EVT_CTL_TYPE_EDGE_0_1);
> +
> +	intel_de_write(display, MTL_PIPEDMC_EVT_CTL_4(intel_dp->psr.pipe),
> +		       val);
> +}
> +
> +static bool is_dc5_dc6_blocked(struct intel_dp *intel_dp) {
> +	struct intel_display *display = to_intel_display(intel_dp);
> +	u32 current_dc_state =
> intel_display_power_get_current_dc_state(display);
> +	struct drm_vblank_crtc *vblank =
> +&display->drm->vblank[intel_dp->psr.pipe];
> +
> +	return (current_dc_state != DC_STATE_EN_UPTO_DC5 &&
> +		current_dc_state != DC_STATE_EN_UPTO_DC6) ||
> +		intel_dp->psr.active_non_psr_pipes ||
> +		READ_ONCE(vblank->enabled);
> +}
> +
>  static void hsw_activate_psr1(struct intel_dp *intel_dp)  {
>  	struct intel_display *display = to_intel_display(intel_dp); @@ -937,6
> +972,12 @@ static void hsw_activate_psr1(struct intel_dp *intel_dp)
> 
>  	intel_de_rmw(display, psr_ctl_reg(display, cpu_transcoder),
>  		     ~EDP_PSR_RESTORE_PSR_ACTIVE_CTX_MASK, val);
> +
> +	/* Wa_16025596647 */
> +	if ((DISPLAY_VER(display) == 20 ||
> +	     IS_DISPLAY_VERx100_STEP(display, 3000, STEP_A0, STEP_B0)) &&
> +	    is_dc5_dc6_blocked(intel_dp))
> +		psr1_apply_underrun_on_idle_wa_locked(intel_dp, true);
>  }
> 
>  static u32 intel_psr2_get_tp_time(struct intel_dp *intel_dp) @@ -1019,8
> +1060,16 @@ static void hsw_activate_psr2(struct intel_dp *intel_dp)
>  	enum transcoder cpu_transcoder = intel_dp->psr.transcoder;
>  	u32 val = EDP_PSR2_ENABLE;
>  	u32 psr_val = 0;
> +	u8 idle_frames;
> 
> -	val |= EDP_PSR2_IDLE_FRAMES(psr_compute_idle_frames(intel_dp));
> +	/* Wa_16025596647 */
> +	if ((DISPLAY_VER(display) == 20 ||
> +	     IS_DISPLAY_VERx100_STEP(display, 3000, STEP_A0, STEP_B0)) &&
> +	    is_dc5_dc6_blocked(intel_dp))
> +		idle_frames = 0;
> +	else
> +		idle_frames = psr_compute_idle_frames(intel_dp);
> +	val |= EDP_PSR2_IDLE_FRAMES(idle_frames);
> 
>  	if (DISPLAY_VER(display) < 14 && !IS_ALDERLAKE_P(dev_priv))
>  		val |= EDP_SU_TRACK_ENABLE;
> @@ -2101,6 +2150,10 @@ static void intel_psr_exit(struct intel_dp *intel_dp)
> 
>  		drm_WARN_ON(display->drm, !(val & EDP_PSR2_ENABLE));
>  	} else {
> +		if (DISPLAY_VER(display) == 20 ||
> +		    IS_DISPLAY_VERx100_STEP(display, 3000, STEP_A0, STEP_B0))
> +			psr1_apply_underrun_on_idle_wa_locked(intel_dp,
> false);
> +
>  		val = intel_de_rmw(display,
>  				   psr_ctl_reg(display, cpu_transcoder),
>  				   EDP_PSR_ENABLE, 0);
> @@ -2312,6 +2365,7 @@ void intel_psr_resume(struct intel_dp *intel_dp)  bool
> intel_psr_needs_block_dc_vblank(const struct intel_crtc_state *crtc_state)  {
>  	struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc);
> +	struct intel_display *display = to_intel_display(crtc_state);
>  	struct intel_encoder *encoder;
> 
>  	for_each_encoder_on_crtc(crtc->base.dev, &crtc->base, encoder) { @@
> -2322,8 +2376,15 @@ bool intel_psr_needs_block_dc_vblank(const struct
> intel_crtc_state *crtc_state)
> 
>  		intel_dp = enc_to_intel_dp(encoder);
> 
> -		if (intel_dp_is_edp(intel_dp) &&
> -		    CAN_PANEL_REPLAY(intel_dp))
> +		if (!intel_dp_is_edp(intel_dp))
> +			continue;
> +
> +		if (CAN_PANEL_REPLAY(intel_dp))
> +			return true;
> +
> +		if ((DISPLAY_VER(display) == 20 ||
> +		     IS_DISPLAY_VERx100_STEP(display, 3000, STEP_A0, STEP_B0))
> &&
> +		    CAN_PSR(intel_dp))
>  			return true;
>  	}
> 
> @@ -3665,42 +3726,6 @@ void intel_psr_unlock(const struct intel_crtc_state
> *crtc_state)
>  	}
>  }
> 
> -/* Wa_16025596647 */
> -static void psr1_apply_underrun_on_idle_wa_locked(struct intel_dp *intel_dp,
> -						  bool dc5_dc6_blocked)
> -{
> -	struct intel_display *display = to_intel_display(intel_dp);
> -	u32 val;
> -
> -	if (dc5_dc6_blocked)
> -		val = DMC_EVT_CTL_ENABLE | DMC_EVT_CTL_RECURRING |
> -			REG_FIELD_PREP(DMC_EVT_CTL_TYPE_MASK,
> -				       DMC_EVT_CTL_TYPE_EDGE_0_1) |
> -			REG_FIELD_PREP(DMC_EVT_CTL_EVENT_ID_MASK,
> -				       DMC_EVT_CTL_EVENT_ID_VBLANK_A);
> -	else
> -		val = REG_FIELD_PREP(DMC_EVT_CTL_EVENT_ID_MASK,
> -				     DMC_EVT_CTL_EVENT_ID_FALSE) |
> -			REG_FIELD_PREP(DMC_EVT_CTL_TYPE_MASK,
> -				       DMC_EVT_CTL_TYPE_EDGE_0_1);
> -
> -	intel_de_write(display, MTL_PIPEDMC_EVT_CTL_4(intel_dp->psr.pipe),
> -		       val);
> -}
> -
> -/* Wa_16025596647 */
> -static bool is_dc5_dc6_blocked(struct intel_dp *intel_dp) -{
> -	struct intel_display *display = to_intel_display(intel_dp);
> -	u32 current_dc_state =
> intel_display_power_get_current_dc_state(display);
> -	struct drm_vblank_crtc *vblank = &display->drm->vblank[intel_dp-
> >psr.pipe];
> -
> -	return (current_dc_state != DC_STATE_EN_UPTO_DC5 &&
> -		current_dc_state != DC_STATE_EN_UPTO_DC6) ||
> -		intel_dp->psr.active_non_psr_pipes ||
> -		READ_ONCE(vblank->enabled);
> -}
> -
>  /* Wa_16025596647 */
>  static void intel_psr_apply_underrun_on_idle_wa_locked(struct intel_dp
> *intel_dp)  {
> --
> 2.43.0



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