[Intel-gfx] [PATCH] drm/i915/display: Support PSR entry VSC packet to be transmitted one frame earlier
Hogander, Jouni
jouni.hogander at intel.com
Wed Oct 25 13:05:09 UTC 2023
On Wed, 2023-10-25 at 12:46 +0300, Mika Kahola wrote:
> Display driver shall read DPCD 00071h[3:1] during configuration
> to get PSR setup time. This register provides the setup time
> requirement on the VSC SDP entry packet. If setup time cannot be
> met with the current timings
> (e.g., PSR setup time + other blanking requirements > blanking time),
> driver should enable sending VSC SDP one frame earlier before sending
> the capture frame.
>
> BSpec: 69895 (PSR Entry Setup Frames 17:16)
>
> Signed-off-by: Mika Kahola <mika.kahola at intel.com>
> ---
> .../drm/i915/display/intel_display_types.h | 1 +
> drivers/gpu/drm/i915/display/intel_psr.c | 35 ++++++++++++++++-
> --
> drivers/gpu/drm/i915/display/intel_psr_regs.h | 2 ++
> 3 files changed, 33 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h
> b/drivers/gpu/drm/i915/display/intel_display_types.h
> index 65ea37fe8cff..a0bcab6f2bec 100644
> --- a/drivers/gpu/drm/i915/display/intel_display_types.h
> +++ b/drivers/gpu/drm/i915/display/intel_display_types.h
> @@ -1710,6 +1710,7 @@ struct intel_psr {
> u32 dc3co_exitline;
> u32 dc3co_exit_delay;
> struct delayed_work dc3co_work;
> + u8 entry_setup_frames;
eDP spec is speaking about 1 frame. Our HW seem to have possibility to
have several.
> };
>
> struct intel_dp {
> diff --git a/drivers/gpu/drm/i915/display/intel_psr.c
> b/drivers/gpu/drm/i915/display/intel_psr.c
> index 4f1f31fc9529..0acb4edae128 100644
> --- a/drivers/gpu/drm/i915/display/intel_psr.c
> +++ b/drivers/gpu/drm/i915/display/intel_psr.c
> @@ -592,6 +592,9 @@ static void intel_psr_enable_sink(struct intel_dp
> *intel_dp)
> if (intel_dp->psr.req_psr2_sdp_prior_scanline)
> dpcd_val |= DP_PSR_SU_REGION_SCANLINE_CAPTURE;
>
> + if (intel_dp->psr.entry_setup_frames > 0)
> + dpcd_val |= DP_PSR_FRAME_CAPTURE;
> +
> drm_dp_dpcd_writeb(&intel_dp->aux, DP_PSR_EN_CFG, dpcd_val);
>
> drm_dp_dpcd_writeb(&intel_dp->aux, DP_SET_POWER,
> DP_SET_POWER_D0);
> @@ -690,6 +693,9 @@ static void hsw_activate_psr1(struct intel_dp
> *intel_dp)
> if (DISPLAY_VER(dev_priv) >= 8)
> val |= EDP_PSR_CRC_ENABLE;
>
> + if (intel_dp->psr.entry_setup_frames > 0)
> + val |= EDP_PSR_ENTRY_SETUP_FRAMES(intel_dp-
> >psr.entry_setup_frames);
> +
> intel_de_rmw(dev_priv, psr_ctl_reg(dev_priv, cpu_transcoder),
> ~EDP_PSR_RESTORE_PSR_ACTIVE_CTX_MASK, val);
> }
> @@ -731,6 +737,7 @@ static void hsw_activate_psr2(struct intel_dp
> *intel_dp)
> {
> struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
> enum transcoder cpu_transcoder = intel_dp->psr.transcoder;
> + u8 frames_before_su_entry;
> u32 val = EDP_PSR2_ENABLE;
>
> val |=
> EDP_PSR2_IDLE_FRAMES(psr_compute_idle_frames(intel_dp));
> @@ -741,7 +748,10 @@ static void hsw_activate_psr2(struct intel_dp
> *intel_dp)
> if (DISPLAY_VER(dev_priv) >= 10 && DISPLAY_VER(dev_priv) <=
> 12)
> val |= EDP_Y_COORDINATE_ENABLE;
>
> - val |= EDP_PSR2_FRAME_BEFORE_SU(max_t(u8, intel_dp-
> >psr.sink_sync_latency + 1, 2));
> + frames_before_su_entry = max_t(u8,
> + intel_dp-
> >psr.sink_sync_latency + 1,
> + 2);
> + val |= EDP_PSR2_FRAME_BEFORE_SU(frames_before_su_entry);
I think you want to do this only once. Below or here.
> val |= intel_psr2_get_tp_time(intel_dp);
>
> if (DISPLAY_VER(dev_priv) >= 12) {
> @@ -785,6 +795,14 @@ static void hsw_activate_psr2(struct intel_dp
> *intel_dp)
> if (intel_dp->psr.req_psr2_sdp_prior_scanline)
> val |= EDP_PSR2_SU_SDP_SCANLINE;
>
> + /* Entry setup frames must be at least 1 less than frames
> before SU entry */
> + if (intel_dp->psr.entry_setup_frames > 0) {
> + val |= EDP_PSR_ENTRY_SETUP_FRAMES(intel_dp-
> >psr.entry_setup_frames);
This is not the correct register. You want to have this in PSR_CTL (not
PSR2_CTL).
> +
> + if (intel_dp->psr.entry_setup_frames >=
> frames_before_su_entry)
> + val |=
> EDP_PSR2_FRAME_BEFORE_SU(frames_before_su_entry + 1);
> + }
> +
Here you are ORing second time. Please do it only once.
> if (intel_dp->psr.psr2_sel_fetch_enabled) {
> u32 tmp;
>
> @@ -1252,10 +1270,17 @@ void intel_psr_compute_config(struct intel_dp
> *intel_dp,
>
> if (intel_usecs_to_scanlines(adjusted_mode, psr_setup_time) >
> adjusted_mode->crtc_vtotal - adjusted_mode->crtc_vdisplay
> - 1) {
> - drm_dbg_kms(&dev_priv->drm,
> - "PSR condition failed: PSR setup time (%d
> us) too long\n",
> - psr_setup_time);
> - return;
> + if (DISPLAY_VER(dev_priv) >= 20) {
> + intel_dp->psr.entry_setup_frames = 1;
> + drm_dbg_kms(&dev_priv->drm,
> + "PSR setup entry frames: %d\n",
> + intel_dp-
> >psr.entry_setup_frames);
> + } else {
> + drm_dbg_kms(&dev_priv->drm,
> + "PSR condition failed: PSR setup
> time (%d us) too long\n",
> + psr_setup_time);
> + return;
> + }
Maybe you could add separate helper for this. E.g.
_compute_psr_setup_frames().
> }
>
> crtc_state->has_psr = true;
> diff --git a/drivers/gpu/drm/i915/display/intel_psr_regs.h
> b/drivers/gpu/drm/i915/display/intel_psr_regs.h
> index d39951383c92..9414c4de5f6e 100644
> --- a/drivers/gpu/drm/i915/display/intel_psr_regs.h
> +++ b/drivers/gpu/drm/i915/display/intel_psr_regs.h
> @@ -35,6 +35,8 @@
> #define
> EDP_PSR_MIN_LINK_ENTRY_TIME_0_LINES REG_FIELD_PREP(EDP_PSR_MIN_LINK_
> ENTRY_TIME_MASK, 3)
> #define EDP_PSR_MAX_SLEEP_TIME_MASK REG_GENMASK(24, 20)
> #define
> EDP_PSR_MAX_SLEEP_TIME(x) REG_FIELD_PREP(EDP_PSR_MAX_SLEEP
> _TIME_MASK, (x))
> +#define EDP_PSR_ENTRY_SETUP_FRAMES_MASK REG_GENMASK(17, 16)
> +#define
> EDP_PSR_ENTRY_SETUP_FRAMES(x) REG_FIELD_PREP(EDP_PSR_E
Maybe LNL prefix here could clarify that this is only in LNL and
beyond.
BR,
Jouni Högander
> NTRY_SETUP_FRAMES_MASK, (x))
> #define EDP_PSR_SKIP_AUX_EXIT REG_BIT(12)
> #define EDP_PSR_TP_MASK REG_BIT(11)
> #define
> EDP_PSR_TP_TP1_TP2 REG_FIELD_PREP(EDP_PSR_TP_MASK,
> 0)
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