[Intel-gfx] [PATCH] drm/i915: Fix TypeC mode initialization during system resume
Imre Deak
imre.deak at intel.com
Mon Sep 26 14:41:26 UTC 2022
On Mon, Sep 26, 2022 at 10:49:19AM +0300, Kahola, Mika wrote:
> > -----Original Message-----
> > From: Intel-gfx <intel-gfx-bounces at lists.freedesktop.org> On Behalf Of Imre
> > Deak
> > Sent: Thursday, September 22, 2022 8:22 PM
> > To: intel-gfx at lists.freedesktop.org
> > Subject: [Intel-gfx] [PATCH] drm/i915: Fix TypeC mode initialization during
> > system resume
> >
> > During system resume DP MST requires AUX to be working already before the
> > HW state readout of the given encoder. Since AUX requires the encoder/PHY
> > TypeC mode to be initialized, which atm only happens during HW state readout,
> > these AUX transfers can change the TypeC mode incorrectly (disconnecting the
> > PHY for an enabled encoder) and trigger the state check WARNs in
> > intel_tc_port_sanitize().
> >
> > Fix this by initializing the TypeC mode earlier both during driver loading and
> > system resume and making sure that the mode can't change until the encoder's
> > state is read out. While at it add the missing DocBook comments and rename
> > intel_tc_port_sanitize()->intel_tc_port_sanitize_mode() for consistency.
> >
> > Signed-off-by: Imre Deak <imre.deak at intel.com>
> > ---
> > drivers/gpu/drm/i915/display/intel_ddi.c | 8 ++-
> > drivers/gpu/drm/i915/display/intel_tc.c | 68 ++++++++++++++++++------
> > drivers/gpu/drm/i915/display/intel_tc.h | 3 +-
> > 3 files changed, 61 insertions(+), 18 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/i915/display/intel_ddi.c
> > b/drivers/gpu/drm/i915/display/intel_ddi.c
> > index 643832d55c282..5ce5e885694c8 100644
> > --- a/drivers/gpu/drm/i915/display/intel_ddi.c
> > +++ b/drivers/gpu/drm/i915/display/intel_ddi.c
> > @@ -3591,7 +3591,7 @@ static void intel_ddi_sync_state(struct intel_encoder
> > *encoder,
> > enum phy phy = intel_port_to_phy(i915, encoder->port);
> >
> > if (intel_phy_is_tc(i915, phy))
> > - intel_tc_port_sanitize(enc_to_dig_port(encoder));
> > + intel_tc_port_sanitize_mode(enc_to_dig_port(encoder));
> >
> > if (crtc_state && intel_crtc_has_dp_encoder(crtc_state))
> > intel_dp_sync_state(encoder, crtc_state); @@ -3789,11
> > +3789,17 @@ static void intel_ddi_encoder_destroy(struct drm_encoder
> > *encoder)
> >
> > static void intel_ddi_encoder_reset(struct drm_encoder *encoder) {
> > + struct drm_i915_private *i915 = to_i915(encoder->dev);
> > struct intel_dp *intel_dp = enc_to_intel_dp(to_intel_encoder(encoder));
> > + struct intel_digital_port *dig_port =
> > enc_to_dig_port(to_intel_encoder(encoder));
> > + enum phy phy = intel_port_to_phy(i915, dig_port->base.port);
> >
> > intel_dp->reset_link_params = true;
> >
> > intel_pps_encoder_reset(intel_dp);
> > +
> > + if (intel_phy_is_tc(i915, phy))
> > + intel_tc_port_init_mode(dig_port);
> > }
> >
> > static const struct drm_encoder_funcs intel_ddi_funcs = { diff --git
> > a/drivers/gpu/drm/i915/display/intel_tc.c
> > b/drivers/gpu/drm/i915/display/intel_tc.c
> > index e5af955b5600f..b0aa1edd83028 100644
> > --- a/drivers/gpu/drm/i915/display/intel_tc.c
> > +++ b/drivers/gpu/drm/i915/display/intel_tc.c
> > @@ -687,18 +687,58 @@ static void
> > intel_tc_port_link_init_refcount(struct intel_digital_port *dig_port,
> > int refcount)
> > {
> > - struct drm_i915_private *i915 = to_i915(dig_port->base.base.dev);
> > -
> > - drm_WARN_ON(&i915->drm, dig_port->tc_link_refcount);
>
> I was thinking whether we should drop this function or not? This is
> now reduced as one liner.
The function also meant to document that setting the refcount directly
(vs. the usual inc/dec on it) is done only during init time.
> Anyway, patch looks ok to me.
>
> Reviewed-by: Mika Kahola <mika.kahola at intel.com>
>
> > dig_port->tc_link_refcount = refcount; }
> >
> > -void intel_tc_port_sanitize(struct intel_digital_port *dig_port)
> > +/**
> > + * intel_tc_port_init_mode: Read out HW state and init the given port's
> > +TypeC mode
> > + * @dig_port: digital port
> > + *
> > + * Read out the HW state and initialize the TypeC mode of @dig_port.
> > +The mode
> > + * will be locked until intel_tc_port_sanitize_mode() is called.
> > + */
> > +void intel_tc_port_init_mode(struct intel_digital_port *dig_port)
> > {
> > struct drm_i915_private *i915 = to_i915(dig_port->base.base.dev);
> > - struct intel_encoder *encoder = &dig_port->base;
> > intel_wakeref_t tc_cold_wref;
> > enum intel_display_power_domain domain;
> > +
> > + mutex_lock(&dig_port->tc_lock);
> > +
> > + drm_WARN_ON(&i915->drm, dig_port->tc_mode !=
> > TC_PORT_DISCONNECTED);
> > + drm_WARN_ON(&i915->drm, dig_port->tc_lock_wakeref);
> > + drm_WARN_ON(&i915->drm, dig_port->tc_link_refcount);
> > +
> > + tc_cold_wref = tc_cold_block(dig_port, &domain);
> > +
> > + dig_port->tc_mode = intel_tc_port_get_current_mode(dig_port);
> > + /* Prevent changing dig_port->tc_mode until
> > intel_tc_port_sanitize_mode() is called. */
> > + intel_tc_port_link_init_refcount(dig_port, 1);
> > + dig_port->tc_lock_wakeref = tc_cold_block(dig_port,
> > +&dig_port->tc_lock_power_domain);
> > +
> > + tc_cold_unblock(dig_port, domain, tc_cold_wref);
> > +
> > + drm_dbg_kms(&i915->drm, "Port %s: init mode (%s)\n",
> > + dig_port->tc_port_name,
> > + tc_port_mode_name(dig_port->tc_mode));
> > +
> > + mutex_unlock(&dig_port->tc_lock);
> > +}
> > +
> > +/**
> > + * intel_tc_port_sanitize_mode: Sanitize the given port's TypeC mode
> > + * @dig_port: digital port
> > + *
> > + * Sanitize @dig_port's TypeC mode wrt. the encoder's state right after
> > +driver
> > + * loading and system resume:
> > + * If the encoder is enabled keep the TypeC mode/PHY connected state
> > +locked until
> > + * the encoder is disabled.
> > + * If the encoder is disabled make sure the PHY is disconnected.
> > + */
> > +void intel_tc_port_sanitize_mode(struct intel_digital_port *dig_port) {
> > + struct drm_i915_private *i915 = to_i915(dig_port->base.base.dev);
> > + struct intel_encoder *encoder = &dig_port->base;
> > int active_links = 0;
> >
> > mutex_lock(&dig_port->tc_lock);
> > @@ -708,21 +748,14 @@ void intel_tc_port_sanitize(struct intel_digital_port
> > *dig_port)
> > else if (encoder->base.crtc)
> > active_links = to_intel_crtc(encoder->base.crtc)->active;
> >
> > - drm_WARN_ON(&i915->drm, dig_port->tc_mode !=
> > TC_PORT_DISCONNECTED);
> > - drm_WARN_ON(&i915->drm, dig_port->tc_lock_wakeref);
> > + drm_WARN_ON(&i915->drm, dig_port->tc_link_refcount != 1);
> > + intel_tc_port_link_init_refcount(dig_port, active_links);
> >
> > - tc_cold_wref = tc_cold_block(dig_port, &domain);
> > -
> > - dig_port->tc_mode = intel_tc_port_get_current_mode(dig_port);
> > if (active_links) {
> > if (!icl_tc_phy_is_connected(dig_port))
> > drm_dbg_kms(&i915->drm,
> > "Port %s: PHY disconnected with %d active
> > link(s)\n",
> > dig_port->tc_port_name, active_links);
> > - intel_tc_port_link_init_refcount(dig_port, active_links);
> > -
> > - dig_port->tc_lock_wakeref = tc_cold_block(dig_port,
> > - &dig_port-
> > >tc_lock_power_domain);
> > } else {
> > /*
> > * TBT-alt is the default mode in any case the PHY ownership is
> > not @@ -736,9 +769,10 @@ void intel_tc_port_sanitize(struct intel_digital_port
> > *dig_port)
> > dig_port->tc_port_name,
> > tc_port_mode_name(dig_port->tc_mode));
> > icl_tc_phy_disconnect(dig_port);
> > - }
> >
> > - tc_cold_unblock(dig_port, domain, tc_cold_wref);
> > + tc_cold_unblock(dig_port, dig_port->tc_lock_power_domain,
> > + fetch_and_zero(&dig_port->tc_lock_wakeref));
> > + }
> >
> > drm_dbg_kms(&i915->drm, "Port %s: sanitize mode (%s)\n",
> > dig_port->tc_port_name,
> > @@ -923,4 +957,6 @@ void intel_tc_port_init(struct intel_digital_port
> > *dig_port, bool is_legacy)
> > dig_port->tc_mode = TC_PORT_DISCONNECTED;
> > dig_port->tc_link_refcount = 0;
> > tc_port_load_fia_params(i915, dig_port);
> > +
> > + intel_tc_port_init_mode(dig_port);
> > }
> > diff --git a/drivers/gpu/drm/i915/display/intel_tc.h
> > b/drivers/gpu/drm/i915/display/intel_tc.h
> > index 6b47b29f551c9..d54082e2d5e8d 100644
> > --- a/drivers/gpu/drm/i915/display/intel_tc.h
> > +++ b/drivers/gpu/drm/i915/display/intel_tc.h
> > @@ -24,7 +24,8 @@ int intel_tc_port_fia_max_lane_count(struct
> > intel_digital_port *dig_port); void intel_tc_port_set_fia_lane_count(struct
> > intel_digital_port *dig_port,
> > int required_lanes);
> >
> > -void intel_tc_port_sanitize(struct intel_digital_port *dig_port);
> > +void intel_tc_port_init_mode(struct intel_digital_port *dig_port); void
> > +intel_tc_port_sanitize_mode(struct intel_digital_port *dig_port);
> > void intel_tc_port_lock(struct intel_digital_port *dig_port); void
> > intel_tc_port_unlock(struct intel_digital_port *dig_port); void
> > intel_tc_port_flush_work(struct intel_digital_port *dig_port);
> > --
> > 2.37.1
>
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