On Wed, 2021-10-06 at 11:50 +0300, Gwan-gyeong Mun wrote:
>
> On 10/6/21 2:18 AM, José Roberto de Souza wrote:
> > Alderlake-P was getting 'max time under evasion' messages when PSR2
> > is enabled, this is due PIPE_SCANLINE/PIPEDSL returning 0 over a
> > period of time longer than VBLANK_EVASION_TIME_US.
> >
> > For PSR1 we had the same issue so intel_psr_wait_for_idle() was
> > implemented to wait for PSR1 to get into idle state but nothing was
> > done for PSR2.
> >
> > For PSR2 we can't only wait for idle state as PSR2 tends to keep
> > into sleep state(ready to send selective updates).
> > Waiting for any state below deep sleep proved to be effective in
> > avoiding the evasion messages and also not wasted a lot of time.
> >
> > v2:
> > - dropping the additional wait_for loops, only the _wait_for_atomic()
> > is necessary
> > - waiting for states below EDP_PSR2_STATUS_STATE_DEEP_SLEEP
> >
> > v3:
> > - dropping intel_wait_for_condition_atomic() function
> >
> > Cc: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
> > Cc: Gwan-gyeong Mun <gwan-gyeong.mun@xxxxxxxxx>
> > Signed-off-by: José Roberto de Souza <jose.souza@xxxxxxxxx>
> > ---
> > .../drm/i915/display/intel_display_debugfs.c | 3 +-
> > drivers/gpu/drm/i915/display/intel_psr.c | 52 +++++++++++--------
> > drivers/gpu/drm/i915/i915_reg.h | 10 ++--
> > 3 files changed, 36 insertions(+), 29 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/i915/display/intel_display_debugfs.c b/drivers/gpu/drm/i915/display/intel_display_debugfs.c
> > index 309d74fd86ce1..d7dd3a57c6170 100644
> > --- a/drivers/gpu/drm/i915/display/intel_display_debugfs.c
> > +++ b/drivers/gpu/drm/i915/display/intel_display_debugfs.c
> > @@ -303,8 +303,7 @@ psr_source_status(struct intel_dp *intel_dp, struct seq_file *m)
> > };
> > val = intel_de_read(dev_priv,
> > EDP_PSR2_STATUS(intel_dp->psr.transcoder));
> > - status_val = (val & EDP_PSR2_STATUS_STATE_MASK) >>
> > - EDP_PSR2_STATUS_STATE_SHIFT;
> > + status_val = REG_FIELD_GET(EDP_PSR2_STATUS_STATE_MASK, val);
> > if (status_val < ARRAY_SIZE(live_status))
> > status = live_status[status_val];
> > } else {
> > diff --git a/drivers/gpu/drm/i915/display/intel_psr.c b/drivers/gpu/drm/i915/display/intel_psr.c
> > index 7a205fd5023bb..ade514fc0a24d 100644
> > --- a/drivers/gpu/drm/i915/display/intel_psr.c
> > +++ b/drivers/gpu/drm/i915/display/intel_psr.c
> > @@ -1809,15 +1809,21 @@ void intel_psr_post_plane_update(const struct intel_atomic_state *state)
> > _intel_psr_post_plane_update(state, crtc_state);
> > }
> >
> > -/**
> > - * psr_wait_for_idle - wait for PSR1 to idle
> > - * @intel_dp: Intel DP
> > - * @out_value: PSR status in case of failure
> > - *
> > - * Returns: 0 on success or -ETIMEOUT if PSR status does not idle.
> > - *
> > - */
> > -static int psr_wait_for_idle(struct intel_dp *intel_dp, u32 *out_value)
> > +static int _psr2_ready_for_pipe_update_locked(struct intel_dp *intel_dp)
> > +{
> > + struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
> > +
> > + /*
> > + * Any state lower than EDP_PSR2_STATUS_STATE_DEEP_SLEEP is enough.
> > + * As all higher states has bit 4 of PSR2 state set we can just wait for
> > + * EDP_PSR2_STATUS_STATE_DEEP_SLEEP to be cleared.
> > + */
> > + return intel_de_wait_for_clear(dev_priv,
> > + EDP_PSR2_STATUS(intel_dp->psr.transcoder),
> > + EDP_PSR2_STATUS_STATE_DEEP_SLEEP, 50);
> Under the DEEP_SLEEP state, there are IDLE, CAPTURE, CPTURE_FS, SLEEP,
> BUFON_FW, ML_UP, SU_STANDBY, etc. In this case, whether the evasion
> messages are completely tested in the state that changes quickly I think
> the test period is a little insufficient.
What is your suggestion of test for this?
I left my Alderlake-P running overnight(more than 12 hours) with a News website open.
This website reloads the page at every 5 minutes, so it entered and exited DC5/6 states several times without any evasion messages.
> I think it may be necessary to test a little more or to have
> confirmation from the HW person in charge.
I can file an issue for this but it will probably several weeks to get an answer.
>
> [PSR2_STATUS]
> +-------+------------+-------------------------------------------------+
> > Value | Name | Description |
> +-------+------------+-------------------------------------------------+
> > 0000b | IDLE | Reset state |
> +-------+------------+-------------------------------------------------+
> > 0001b | CAPTURE | Send capture frame |
> +-------+------------+-------------------------------------------------+
> > 0010b | CPTURE_FS | Fast sleep after capture frame is sent |
> +-------+------------+-------------------------------------------------+
> > 0011b | SLEEP | Selective Update |
> +-------+------------+-------------------------------------------------+
> > 0100b | BUFON_FW | Turn Buffer on and Send Fast wake |
> +-------+------------+-------------------------------------------------+
> > 0101b | ML_UP | Turn Main link up and send SR |
> +-------+------------+-------------------------------------------------+
> > 0110b | SU_STANDBY | Selective update or Standby state |
> +-------+------------+-------------------------------------------------+
> > 0111b | FAST_SLEEP | Send Fast sleep |
>
> +-------+------------+-------------------------------------------------+
> > 1000b | DEEP_SLEEP | Enter Deep sleep |
> +-------+------------+-------------------------------------------------+
> > 1001b | BUF_ON | Turn ON IO Buffer |
> +-------+------------+-------------------------------------------------+
> > 1010b | TG_ON | Turn ON Timing Generator |
> +-------+------------+-------------------------------------------------+
> > 1011b | BUFON_FW_2 |Turn Buffer on and Send Fast wake for 3 BlockCase|
> +-------+------------+-------------------------------------------------+
> > +}
> > +
> > +static int _psr1_ready_for_pipe_update_locked(struct intel_dp *intel_dp)
> > {
> > struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
> >
> > @@ -1827,15 +1833,13 @@ static int psr_wait_for_idle(struct intel_dp *intel_dp, u32 *out_value)
> > * exit training time + 1.5 ms of aux channel handshake. 50 ms is
> > * defensive enough to cover everything.
> > */
> > - return __intel_wait_for_register(&dev_priv->uncore,
> > - EDP_PSR_STATUS(intel_dp->psr.transcoder),
> > - EDP_PSR_STATUS_STATE_MASK,
> > - EDP_PSR_STATUS_STATE_IDLE, 2, 50,
> > - out_value);
> > + return intel_de_wait_for_clear(dev_priv,
> > + EDP_PSR_STATUS(intel_dp->psr.transcoder),
> > + EDP_PSR_STATUS_STATE_MASK, 50);
> > }
> >
> > /**
> > - * intel_psr_wait_for_idle - wait for PSR1 to idle
> > + * intel_psr_wait_for_idle - 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
> > @@ -1852,19 +1856,23 @@ void intel_psr_wait_for_idle(const struct intel_crtc_state *new_crtc_state)
> > for_each_intel_encoder_mask_with_psr(&dev_priv->drm, encoder,
> > new_crtc_state->uapi.encoder_mask) {
> > struct intel_dp *intel_dp = enc_to_intel_dp(encoder);
> > - u32 psr_status;
> > + int ret;
> >
> > mutex_lock(&intel_dp->psr.lock);
> > - if (!intel_dp->psr.enabled || intel_dp->psr.psr2_enabled) {
> > +
> > + if (!intel_dp->psr.enabled) {
> > mutex_unlock(&intel_dp->psr.lock);
> > continue;
> > }
> >
> > - /* when the PSR1 is enabled */
> > - if (psr_wait_for_idle(intel_dp, &psr_status))
> > - drm_err(&dev_priv->drm,
> > - "PSR idle timed out 0x%x, atomic update may fail\n",
> > - psr_status);
> > + if (intel_dp->psr.psr2_enabled)
> > + ret = _psr2_ready_for_pipe_update_locked(intel_dp);
> > + else
> > + ret = _psr1_ready_for_pipe_update_locked(intel_dp);
> > +
> > + if (ret)
> > + drm_err(&dev_priv->drm, "PSR wait timed out, atomic update may fail\n");
> > +
> > mutex_unlock(&intel_dp->psr.lock);
> > }
> > }
> > diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
> > index a897f4abea0c3..e101579d3a4d8 100644
> > --- a/drivers/gpu/drm/i915/i915_reg.h
> > +++ b/drivers/gpu/drm/i915/i915_reg.h
> > @@ -4700,11 +4700,11 @@ enum {
> > #define PSR_EVENT_LPSP_MODE_EXIT (1 << 1)
> > #define PSR_EVENT_PSR_DISABLE (1 << 0)
> >
> > -#define _PSR2_STATUS_A 0x60940
> > -#define _PSR2_STATUS_EDP 0x6f940
> > -#define EDP_PSR2_STATUS(tran) _MMIO_TRANS2(tran, _PSR2_STATUS_A)
> > -#define EDP_PSR2_STATUS_STATE_MASK (0xf << 28)
> > -#define EDP_PSR2_STATUS_STATE_SHIFT 28
> > +#define _PSR2_STATUS_A 0x60940
> > +#define _PSR2_STATUS_EDP 0x6f940
> > +#define EDP_PSR2_STATUS(tran) _MMIO_TRANS2(tran, _PSR2_STATUS_A)
> > +#define EDP_PSR2_STATUS_STATE_MASK REG_GENMASK(31, 28)
> > +#define EDP_PSR2_STATUS_STATE_DEEP_SLEEP REG_FIELD_PREP(EDP_PSR2_STATUS_STATE_MASK, 0x8)
> >
> > #define _PSR2_SU_STATUS_A 0x60914
> > #define _PSR2_SU_STATUS_EDP 0x6f914
> >
