On Tue, 2025-09-23 at 09:26 +0000, Manna, Animesh wrote:
>
>
> > -----Original Message-----
> > From: Intel-xe <[email protected]> On Behalf
> > Of Jouni
> > Högander
> > Sent: Friday, September 5, 2025 12:31 PM
> > To: [email protected]; [email protected]
> > Cc: Hogander, Jouni <[email protected]>
> > Subject: [PATCH] drm/i915/alpm: Compute ALPM parameters into
> > crtc_state-
> > > alpm_parameters
> >
> > Currently ALPM parameters are computed directly into
> > intel_dp->alpm_parameters. This is a problem when compute config
> > ends up
> > to
> > not using the computed state.
> >
> > Fix this by adding ALPM parameters into intel_crtc_state and
> > compute into
> > there. Copy needed parts of crtc_state->alpm_parameters into
> > intel_dp->alpm.alpm_parameters (io_wake_lines and fast_wake_lines)
> > when
> > they are configured into HW.
> >
> > Signed-off-by: Jouni Högander <[email protected]>
> > ---
> > drivers/gpu/drm/i915/display/intel_alpm.c | 38 ++++++++++-----
> > ----
> > drivers/gpu/drm/i915/display/intel_alpm.h | 2 +-
> > .../drm/i915/display/intel_display_types.h | 16 +++++---
> > drivers/gpu/drm/i915/display/intel_psr.c | 20 +++++-----
> > 4 files changed, 43 insertions(+), 33 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/i915/display/intel_alpm.c
> > b/drivers/gpu/drm/i915/display/intel_alpm.c
> > index ed7a7ed486b5..bbc4fa2e084e 100644
> > --- a/drivers/gpu/drm/i915/display/intel_alpm.c
> > +++ b/drivers/gpu/drm/i915/display/intel_alpm.c
> > @@ -133,7 +133,7 @@ static int
> > _lnl_compute_aux_less_wake_time(const
> > struct intel_crtc_state *crtc_s
> >
> > static int
> > _lnl_compute_aux_less_alpm_params(struct intel_dp *intel_dp,
> > - const struct intel_crtc_state
> > *crtc_state)
> > + struct intel_crtc_state
> > *crtc_state)
> > {
> > struct intel_display *display =
> > to_intel_display(intel_dp);
> > int aux_less_wake_time, aux_less_wake_lines,
> > silence_period,
> > @@ -157,15 +157,15 @@ _lnl_compute_aux_less_alpm_params(struct
> > intel_dp *intel_dp,
> > if (display->params.psr_safest_params)
> > aux_less_wake_lines =
> > ALPM_CTL_AUX_LESS_WAKE_TIME_MASK;
> >
> > - intel_dp->alpm_parameters.aux_less_wake_lines =
> > aux_less_wake_lines;
> > - intel_dp->alpm_parameters.silence_period_sym_clocks =
> > silence_period;
> > - intel_dp->alpm_parameters.lfps_half_cycle_num_of_syms =
> > lfps_half_cycle;
> > + crtc_state->alpm_parameters.aux_less_wake_lines =
> > aux_less_wake_lines;
> > + crtc_state->alpm_parameters.silence_period_sym_clocks =
> > silence_period;
> > + crtc_state->alpm_parameters.lfps_half_cycle_num_of_syms =
> > lfps_half_cycle;
> >
> > return true;
> > }
> >
> > static bool _lnl_compute_alpm_params(struct intel_dp *intel_dp,
> > - const struct intel_crtc_state
> > *crtc_state)
> > + struct intel_crtc_state
> > *crtc_state)
> > {
> > struct intel_display *display =
> > to_intel_display(intel_dp);
> > int check_entry_lines;
> > @@ -186,7 +186,7 @@ static bool _lnl_compute_alpm_params(struct
> > intel_dp *intel_dp,
> > if (display->params.psr_safest_params)
> > check_entry_lines = 15;
> >
> > - intel_dp->alpm_parameters.check_entry_lines =
> > check_entry_lines;
> > + crtc_state->alpm_parameters.check_entry_lines =
> > check_entry_lines;
> >
> > return true;
> > }
> > @@ -217,7 +217,7 @@ static int io_buffer_wake_time(const struct
> > intel_crtc_state *crtc_state)
> > }
> >
> > bool intel_alpm_compute_params(struct intel_dp *intel_dp,
> > - const struct intel_crtc_state
> > *crtc_state)
> > + struct intel_crtc_state
> > *crtc_state)
> > {
> > struct intel_display *display =
> > to_intel_display(intel_dp);
> > int io_wake_lines, io_wake_time, fast_wake_lines,
> > fast_wake_time;
> > @@ -255,8 +255,8 @@ bool intel_alpm_compute_params(struct intel_dp
> > *intel_dp,
> > io_wake_lines = fast_wake_lines = max_wake_lines;
> >
> > /* According to Bspec lower limit should be set as 7
> > lines. */
> > - intel_dp->alpm_parameters.io_wake_lines =
> > max(io_wake_lines, 7);
> > - intel_dp->alpm_parameters.fast_wake_lines =
> > max(fast_wake_lines,
> > 7);
> > + crtc_state->alpm_parameters.io_wake_lines =
> > max(io_wake_lines,
> > 7);
> > + crtc_state->alpm_parameters.fast_wake_lines =
> > max(fast_wake_lines, 7);
> >
> > return true;
> > }
> > @@ -306,9 +306,9 @@ void intel_alpm_lobf_compute_config(struct
> > intel_dp
> > *intel_dp,
> > adjusted_mode->crtc_vdisplay -
> > context_latency;
> > first_sdp_position = adjusted_mode->crtc_vtotal -
> > adjusted_mode-
> > > crtc_vsync_start;
> > if (intel_alpm_aux_less_wake_supported(intel_dp))
> > - waketime_in_lines = intel_dp-
> > > alpm_parameters.io_wake_lines;
> > + waketime_in_lines = crtc_state-
> > > alpm_parameters.io_wake_lines;
> > else
> > - waketime_in_lines = intel_dp-
> > > alpm_parameters.aux_less_wake_lines;
> > + waketime_in_lines = crtc_state-
> > > alpm_parameters.aux_less_wake_lines;
> >
> > crtc_state->has_lobf = (context_latency + guardband) >
> > (first_sdp_position + waketime_in_lines);
> > @@ -334,7 +334,7 @@ static void lnl_alpm_configure(struct intel_dp
> > *intel_dp,
> > alpm_ctl = ALPM_CTL_ALPM_ENABLE |
> > ALPM_CTL_ALPM_AUX_LESS_ENABLE |
> >
> > ALPM_CTL_AUX_LESS_SLEEP_HOLD_TIME_50_SYMBOLS |
> > - ALPM_CTL_AUX_LESS_WAKE_TIME(intel_dp-
> > > alpm_parameters.aux_less_wake_lines);
> > + ALPM_CTL_AUX_LESS_WAKE_TIME(crtc_state-
> > > alpm_parameters.aux_less_wake_lines);
> >
> > if (intel_dp->as_sdp_supported) {
> > u32 pr_alpm_ctl =
> > PR_ALPM_CTL_ADAPTIVE_SYNC_SDP_POSITION_T1;
> > @@ -352,7 +352,7 @@ static void lnl_alpm_configure(struct intel_dp
> > *intel_dp,
> >
> > } else {
> > alpm_ctl = ALPM_CTL_EXTENDED_FAST_WAKE_ENABLE |
> > - ALPM_CTL_EXTENDED_FAST_WAKE_TIME(intel_dp-
> > > alpm_parameters.fast_wake_lines);
> > + ALPM_CTL_EXTENDED_FAST_WAKE_TIME(crtc_stat
> > e-
> > > alpm_parameters.fast_wake_lines);
> > }
> >
> > if (crtc_state->has_lobf) {
> > @@ -360,7 +360,7 @@ static void lnl_alpm_configure(struct intel_dp
> > *intel_dp,
> > drm_dbg_kms(display->drm, "Link off between frames
> > (LOBF) enabled\n");
> > }
> >
> > - alpm_ctl |= ALPM_CTL_ALPM_ENTRY_CHECK(intel_dp-
> > > alpm_parameters.check_entry_lines);
> > + alpm_ctl |= ALPM_CTL_ALPM_ENTRY_CHECK(crtc_state-
> > > alpm_parameters.check_entry_lines);
> >
> > intel_de_write(display, ALPM_CTL(display, cpu_transcoder),
> > alpm_ctl);
> > mutex_unlock(&intel_dp->alpm_parameters.lock);
> > @@ -371,6 +371,8 @@ void intel_alpm_configure(struct intel_dp
> > *intel_dp,
> > {
> > lnl_alpm_configure(intel_dp, crtc_state);
> > intel_dp->alpm_parameters.transcoder = crtc_state-
> > > cpu_transcoder;
> > + intel_dp->alpm_parameters.io_wake_lines = crtc_state-
> > > alpm_parameters.io_wake_lines;
> > + intel_dp->alpm_parameters.fast_wake_lines = crtc_state-
> > > alpm_parameters.fast_wake_lines;
>
> As I understood io_wake_lines and fast_wake_lines will be needed in
> psr_work() and getting crtc_state will not be possible.
> Is it needed to store to crtc_state? maybe for the above reason we
> can keep in intel_dp only.
Whole point of the patch is to have computed parameters that are not
yet applied in crtc_state. Why this patch set is doing that: please
check commit message and ask for clarification/improvements if needed.
> Even if we don’t write into h/w still these values are saved in
> intel_dp during early return from lnl_alpm_configure().
How about if we do it only when intel_psr_needs_alpm() == true?
>
> > }
> >
> > void intel_alpm_port_configure(struct intel_dp *intel_dp,
> > @@ -388,14 +390,14 @@ void intel_alpm_port_configure(struct
> > intel_dp
> > *intel_dp,
> > PORT_ALPM_CTL_MAX_PHY_SWING_SETUP(15) |
> > PORT_ALPM_CTL_MAX_PHY_SWING_HOLD(0) |
> > PORT_ALPM_CTL_SILENCE_PERIOD(
> > - intel_dp-
> > > alpm_parameters.silence_period_sym_clocks);
> > + crtc_state-
> > > alpm_parameters.silence_period_sym_clocks);
> > lfps_ctl_val =
> > PORT_ALPM_LFPS_CTL_LFPS_CYCLE_COUNT(LFPS_CYCLE_COUNT) |
> >
> > PORT_ALPM_LFPS_CTL_LFPS_HALF_CYCLE_DURATION(
> > - intel_dp-
> > > alpm_parameters.lfps_half_cycle_num_of_syms) |
> > + crtc_state-
> > > alpm_parameters.lfps_half_cycle_num_of_syms) |
> >
> > PORT_ALPM_LFPS_CTL_FIRST_LFPS_HALF_CYCLE_DURATION(
> > - intel_dp-
> > > alpm_parameters.lfps_half_cycle_num_of_syms) |
> > + crtc_state-
> > > alpm_parameters.lfps_half_cycle_num_of_syms) |
> >
> > PORT_ALPM_LFPS_CTL_LAST_LFPS_HALF_CYCLE_DURATION(
> > - intel_dp-
> > > alpm_parameters.lfps_half_cycle_num_of_syms);
> > + crtc_state-
> > > alpm_parameters.lfps_half_cycle_num_of_syms);
> > }
> >
> > intel_de_write(display, PORT_ALPM_CTL(port),
> > alpm_ctl_val);
> > diff --git a/drivers/gpu/drm/i915/display/intel_alpm.h
> > b/drivers/gpu/drm/i915/display/intel_alpm.h
> > index a861c20b5d79..53599b464dea 100644
> > --- a/drivers/gpu/drm/i915/display/intel_alpm.h
> > +++ b/drivers/gpu/drm/i915/display/intel_alpm.h
> > @@ -17,7 +17,7 @@ struct intel_crtc;
> >
> > void intel_alpm_init(struct intel_dp *intel_dp);
> > bool intel_alpm_compute_params(struct intel_dp *intel_dp,
> > - const struct intel_crtc_state
> > *crtc_state);
> > + struct intel_crtc_state
> > *crtc_state);
> > void intel_alpm_lobf_compute_config(struct intel_dp *intel_dp,
> > struct intel_crtc_state
> > *crtc_state,
> > struct drm_connector_state
> > *conn_state);
> > diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h
> > b/drivers/gpu/drm/i915/display/intel_display_types.h
> > index fd9d2527889b..1fc778067397 100644
> > --- a/drivers/gpu/drm/i915/display/intel_display_types.h
> > +++ b/drivers/gpu/drm/i915/display/intel_display_types.h
> > @@ -1339,6 +1339,17 @@ struct intel_crtc_state {
> >
> > /* LOBF flag */
> > bool has_lobf;
> > +
> > + struct {
> > + u8 io_wake_lines;
> > + u8 fast_wake_lines;
> > +
> > + /* LNL and beyond */
> > + u8 check_entry_lines;
> > + u8 aux_less_wake_lines;
> > + u8 silence_period_sym_clocks;
> > + u8 lfps_half_cycle_num_of_syms;
> > + } alpm_parameters;
>
> The naming can be alpm_state here instead of alpm_parameters which is
> present in intel_dp.
Ok, I will change this.
BR,
Jouni Högander
>
> Regards,
> Animesh
>
> > };
> >
> > enum intel_pipe_crc_source {
> > @@ -1847,11 +1858,6 @@ struct intel_dp {
> > enum transcoder transcoder;
> > struct mutex lock;
> >
> > - /* LNL and beyond */
> > - u8 check_entry_lines;
> > - u8 aux_less_wake_lines;
> > - u8 silence_period_sym_clocks;
> > - u8 lfps_half_cycle_num_of_syms;
> > bool lobf_disable_debug;
> > bool sink_alpm_error;
> > } alpm_parameters;
> > diff --git a/drivers/gpu/drm/i915/display/intel_psr.c
> > b/drivers/gpu/drm/i915/display/intel_psr.c
> > index 22433fe2ee14..dd6df3154508 100644
> > --- a/drivers/gpu/drm/i915/display/intel_psr.c
> > +++ b/drivers/gpu/drm/i915/display/intel_psr.c
> > @@ -953,15 +953,16 @@ static u32 intel_psr2_get_tp_time(struct
> > intel_dp
> > *intel_dp)
> > return val;
> > }
> >
> > -static int psr2_block_count_lines(struct intel_dp *intel_dp)
> > +static int
> > +psr2_block_count_lines(u8 io_wake_lines, u8 fast_wake_lines)
> > {
> > - return intel_dp->alpm_parameters.io_wake_lines < 9 &&
> > - intel_dp->alpm_parameters.fast_wake_lines < 9 ? 8
> > : 12;
> > + return io_wake_lines < 9 && fast_wake_lines < 9 ? 8 : 12;
> > }
> >
> > static int psr2_block_count(struct intel_dp *intel_dp)
> > {
> > - return psr2_block_count_lines(intel_dp) / 4;
> > + return psr2_block_count_lines(intel_dp-
> > > alpm_parameters.io_wake_lines,
> > + intel_dp-
> > > alpm_parameters.fast_wake_lines) / 4;
> > }
> >
> > static u8 frames_before_su_entry(struct intel_dp *intel_dp)
> > @@ -1367,11 +1368,12 @@ static bool
> > wake_lines_fit_into_vblank(struct
> > intel_dp *intel_dp,
> > int wake_lines;
> >
> > if (aux_less)
> > - wake_lines = intel_dp-
> > > alpm_parameters.aux_less_wake_lines;
> > + wake_lines = crtc_state-
> > > alpm_parameters.aux_less_wake_lines;
> > else
> > wake_lines = DISPLAY_VER(display) < 20 ?
> > - psr2_block_count_lines(intel_dp) :
> > - intel_dp->alpm_parameters.io_wake_lines;
> > + psr2_block_count_lines(crtc_state-
> > > alpm_parameters.io_wake_lines,
> > + crtc_state-
> > > alpm_parameters.fast_wake_lines) :
> > + crtc_state->alpm_parameters.io_wake_lines;
> >
> > if (crtc_state->req_psr2_sdp_prior_scanline)
> > vblank -= 1;
> > @@ -1384,7 +1386,7 @@ static bool wake_lines_fit_into_vblank(struct
> > intel_dp *intel_dp,
> > }
> >
> > static bool alpm_config_valid(struct intel_dp *intel_dp,
> > - const struct intel_crtc_state
> > *crtc_state,
> > + struct intel_crtc_state *crtc_state,
> > bool aux_less)
> > {
> > struct intel_display *display =
> > to_intel_display(intel_dp);
> > @@ -1589,7 +1591,7 @@ static bool _psr_compute_config(struct
> > intel_dp
> > *intel_dp,
> >
> > static bool
> > _panel_replay_compute_config(struct intel_dp *intel_dp,
> > - const struct intel_crtc_state
> > *crtc_state,
> > + struct intel_crtc_state *crtc_state,
> > const struct drm_connector_state
> > *conn_state)
> > {
> > struct intel_display *display =
> > to_intel_display(intel_dp);
> > --
> > 2.43.0
>
