> -----Original Message-----
> From: Manna, Animesh
> Sent: Tuesday, February 25, 2025 2:32 PM
> To: Nikula, Jani <jani.nikula@xxxxxxxxx>; intel-gfx@xxxxxxxxxxxxxxxxxxxxx;
> intel-xe@xxxxxxxxxxxxxxxxxxxxx
> Cc: Hogander, Jouni <jouni.hogander@xxxxxxxxx>; B, Jeevan
> <Jeevan.B@xxxxxxxxx>
> Subject: RE: [PATCH v4 2/8] drm/i915/lobf: Disintegrate alpm_disable from
> psr_disable
>
>
>
> > -----Original Message-----
> > From: Nikula, Jani <jani.nikula@xxxxxxxxx>
> > Sent: Monday, February 24, 2025 4:15 PM
> > To: Manna, Animesh <animesh.manna@xxxxxxxxx>; intel-
> > gfx@xxxxxxxxxxxxxxxxxxxxx; intel-xe@xxxxxxxxxxxxxxxxxxxxx
> > Cc: Hogander, Jouni <jouni.hogander@xxxxxxxxx>; B, Jeevan
> > <jeevan.b@xxxxxxxxx>; Manna, Animesh <animesh.manna@xxxxxxxxx>
> > Subject: Re: [PATCH v4 2/8] drm/i915/lobf: Disintegrate alpm_disable
> > from psr_disable
> >
> > On Mon, 24 Feb 2025, Animesh Manna <animesh.manna@xxxxxxxxx>
> wrote:
> > > Currently clearing of alpm registers is done through psr_disable()
> > > which is always not correct, without psr also alpm can exist. So
> > > dis-integrate alpm_disable() from psr_disable().
> > >
> > > Signed-off-by: Animesh Manna <animesh.manna@xxxxxxxxx>
> > > ---
> > > drivers/gpu/drm/i915/display/intel_alpm.c | 21
> +++++++++++++++++++
> > > drivers/gpu/drm/i915/display/intel_alpm.h | 1 +
> > > drivers/gpu/drm/i915/display/intel_ddi.c | 2 ++
> > > .../drm/i915/display/intel_display_types.h | 1 +
> > > drivers/gpu/drm/i915/display/intel_psr.c | 11 ----------
> > > 5 files changed, 25 insertions(+), 11 deletions(-)
> > >
> > > diff --git a/drivers/gpu/drm/i915/display/intel_alpm.c
> > > b/drivers/gpu/drm/i915/display/intel_alpm.c
> > > index a53ed83f6b22..d94c96ba46b1 100644
> > > --- a/drivers/gpu/drm/i915/display/intel_alpm.c
> > > +++ b/drivers/gpu/drm/i915/display/intel_alpm.c
> > > @@ -365,6 +365,7 @@ void intel_alpm_configure(struct intel_dp
> > *intel_dp,
> > > const struct intel_crtc_state *crtc_state) {
> > > lnl_alpm_configure(intel_dp, crtc_state);
> > > + intel_dp->alpm_parameters.transcoder = crtc_state-
> > >cpu_transcoder;
> >
> > Why do we need to store this?
>
> While refactoring found that some places where we don't have access to
> crtc_state and only intel_dp is passed, using cpu_transcoder we can access
> ALPM register, will relook again and try to drop the saving of transcoder in
> intel_dp.
>
> >
> > > }
> > >
> > > void intel_alpm_post_plane_update(struct intel_atomic_state *state,
> > > @@ -440,3 +441,23 @@ void intel_alpm_lobf_debugfs_add(struct
> > intel_connector *connector)
> > > debugfs_create_file("i915_edp_lobf_info", 0444, root,
> > > connector, &i915_edp_lobf_info_fops); }
> > > +
> > > +void intel_alpm_disable(struct intel_dp *intel_dp) {
> > > + struct intel_display *display = to_intel_display(intel_dp);
> > > + enum transcoder cpu_transcoder =
> > > +intel_dp->alpm_parameters.transcoder;
> > > +
> > > + if (DISPLAY_VER(display) < 20)
> > > + return;
> > > +
> > > + if (!(intel_de_read(display, ALPM_CTL(display, cpu_transcoder)) &
> > ALPM_CTL_ALPM_ENABLE))
> > > + return;
> >
> > Why are we checking the hardware state here? We should know what state
> > the hardware is in, right?
> >
>
> Agree, we can drop the above read.
>
> > > +
> > > + intel_de_rmw(display, ALPM_CTL(display, cpu_transcoder),
> > > + ALPM_CTL_ALPM_ENABLE | ALPM_CTL_LOBF_ENABLE |
> > > + ALPM_CTL_ALPM_AUX_LESS_ENABLE, 0);
> > > +
> > > + intel_de_rmw(display,
> > > + PORT_ALPM_CTL(cpu_transcoder),
> > > + PORT_ALPM_CTL_ALPM_AUX_LESS_ENABLE, 0); }
> > > diff --git a/drivers/gpu/drm/i915/display/intel_alpm.h
> > > b/drivers/gpu/drm/i915/display/intel_alpm.h
> > > index 2f862b0476a8..91f51fb24f98 100644
> > > --- a/drivers/gpu/drm/i915/display/intel_alpm.h
> > > +++ b/drivers/gpu/drm/i915/display/intel_alpm.h
> > > @@ -28,4 +28,5 @@ void intel_alpm_post_plane_update(struct
> > > intel_atomic_state *state, void intel_alpm_lobf_debugfs_add(struct
> > > intel_connector *connector); bool
> > > intel_alpm_aux_wake_supported(struct intel_dp *intel_dp); bool
> > > intel_alpm_aux_less_wake_supported(struct intel_dp *intel_dp);
> > > +void intel_alpm_disable(struct intel_dp *intel_dp);
> > > #endif
> > > diff --git a/drivers/gpu/drm/i915/display/intel_ddi.c
> > > b/drivers/gpu/drm/i915/display/intel_ddi.c
> > > index 7937f4de66cb..26aa32d4d50e 100644
> > > --- a/drivers/gpu/drm/i915/display/intel_ddi.c
> > > +++ b/drivers/gpu/drm/i915/display/intel_ddi.c
> > > @@ -35,6 +35,7 @@
> > > #include "i915_drv.h"
> > > #include "i915_reg.h"
> > > #include "icl_dsi.h"
> > > +#include "intel_alpm.h"
> > > #include "intel_audio.h"
> > > #include "intel_audio_regs.h"
> > > #include "intel_backlight.h"
> > > @@ -3570,6 +3571,7 @@ static void intel_ddi_disable_dp(struct
> > intel_atomic_state *state,
> > > intel_dp->link_trained = false;
> > >
> > > intel_psr_disable(intel_dp, old_crtc_state);
> > > + intel_alpm_disable(intel_dp);
> >
> > We have old crtc state here, why do we save the transcoder to intel_dp
> > and use that?
>
> Got it, we can drop saving of transcoder in intel_dp here.
Tried removing transcoder from alpm_parameters but later found that for some erroneous case where we don't have crtc_state like sink error communicated through short pulse, we need to store transcoder in intel_dp. The same is done for PSR as well. So currently keeping it in my latest version on the patch.
Regards,
Animesh
>
> Regards,
> Animesh
>
> >
> > > intel_edp_backlight_off(old_conn_state);
> > > /* Disable the decompression in DP Sink */
> > > intel_dp_sink_disable_decompression(state,
> > > diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h
> > > b/drivers/gpu/drm/i915/display/intel_display_types.h
> > > index 4440521e3e9e..b78721c451b8 100644
> > > --- a/drivers/gpu/drm/i915/display/intel_display_types.h
> > > +++ b/drivers/gpu/drm/i915/display/intel_display_types.h
> > > @@ -1801,6 +1801,7 @@ struct intel_dp {
> > > struct {
> > > u8 io_wake_lines;
> > > u8 fast_wake_lines;
> > > + enum transcoder transcoder;
> > >
> > > /* LNL and beyond */
> > > u8 check_entry_lines;
> > > diff --git a/drivers/gpu/drm/i915/display/intel_psr.c
> > > b/drivers/gpu/drm/i915/display/intel_psr.c
> > > index c1dd9c739fd4..1d202f2eb356 100644
> > > --- a/drivers/gpu/drm/i915/display/intel_psr.c
> > > +++ b/drivers/gpu/drm/i915/display/intel_psr.c
> > > @@ -2141,17 +2141,6 @@ static void intel_psr_disable_locked(struct
> > intel_dp *intel_dp)
> > > if (intel_dp_is_edp(intel_dp))
> > >
> > > intel_snps_phy_update_psr_power_state(&dp_to_dig_port(intel_dp)-
> > >base,
> > > false);
> > >
> > > - /* Panel Replay on eDP is always using ALPM aux less. */
> > > - if (intel_dp->psr.panel_replay_enabled &&
> > intel_dp_is_edp(intel_dp)) {
> > > - intel_de_rmw(display, ALPM_CTL(display, cpu_transcoder),
> > > - ALPM_CTL_ALPM_ENABLE |
> > > - ALPM_CTL_ALPM_AUX_LESS_ENABLE, 0);
> > > -
> > > - intel_de_rmw(display,
> > > - PORT_ALPM_CTL(cpu_transcoder),
> > > - PORT_ALPM_CTL_ALPM_AUX_LESS_ENABLE, 0);
> > > - }
> > > -
> > > /* Disable PSR on Sink */
> > > if (!intel_dp->psr.panel_replay_enabled) {
> > > drm_dp_dpcd_writeb(&intel_dp->aux, DP_PSR_EN_CFG, 0);
> >
> > --
> > Jani Nikula, Intel
