drm/i915: Beef up the IPS vs. CRC workaround

Oneshot disabling of IPS when CRC capturing is started is insufficient.
IPS may get re-enabled by any plane update, and hence tests that keep
CRC capturing on across plane updates will start to see inconsistent
results as soon as IPS kicks back in. Add a new knob into the crtc state
to make sure IPS stays disabled as long as CRC capturing is enabled.

Forcing a modeset is the easiest way to handle this since that's already
how we do the panel fitter workaround. It's a little heavy handed just
for IPS, but seeing as we might already do the panel fitter workaround
I think it's better to follow that. We migth want to optimize both cases
later if someone gets too upset by the extra delay from the modeset.

v2: Check the right thing when deciding whether to force a modeset
v3: Rebase, check HAS_IPS before forcing a modeset,
    move ips_force_disable check into pipe_config_supports_ips()

Cc: Paulo Zanoni <paulo.r.zanoni@intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Marta Lofstedt <marta.lofstedt@intel.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=101664
Reviewed-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Tested-by: Marta Lofsted <marta.lofstedt@intel.com> #v2
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20170817145509.15549-1-ville.syrjala@linux.intel.com

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index ad74d1d..eda1aa0 100644 (file)
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -6263,6 +6263,9 @@ retry:
 static bool pipe_config_supports_ips(struct drm_i915_private *dev_priv,
                                     struct intel_crtc_state *pipe_config)
 {
+       if (pipe_config->ips_force_disable)
+               return false;
+
        if (pipe_config->pipe_bpp > 24)
                return false;
 
@@ -10830,7 +10833,7 @@ clear_intel_crtc_state(struct intel_crtc_state *crtc_state)
        struct intel_dpll_hw_state dpll_hw_state;
        struct intel_shared_dpll *shared_dpll;
        struct intel_crtc_wm_state wm_state;
-       bool force_thru;
+       bool force_thru, ips_force_disable;
 
        /* FIXME: before the switch to atomic started, a new pipe_config was
         * kzalloc'd. Code that depends on any field being zero should be
@@ -10841,6 +10844,7 @@ clear_intel_crtc_state(struct intel_crtc_state *crtc_state)
        shared_dpll = crtc_state->shared_dpll;
        dpll_hw_state = crtc_state->dpll_hw_state;
        force_thru = crtc_state->pch_pfit.force_thru;
+       ips_force_disable = crtc_state->ips_force_disable;
        if (IS_G4X(dev_priv) ||
            IS_VALLEYVIEW(dev_priv) || IS_CHERRYVIEW(dev_priv))
                wm_state = crtc_state->wm;
@@ -10854,6 +10858,7 @@ clear_intel_crtc_state(struct intel_crtc_state *crtc_state)
        crtc_state->shared_dpll = shared_dpll;
        crtc_state->dpll_hw_state = dpll_hw_state;
        crtc_state->pch_pfit.force_thru = force_thru;
+       crtc_state->ips_force_disable = ips_force_disable;
        if (IS_G4X(dev_priv) ||
            IS_VALLEYVIEW(dev_priv) || IS_CHERRYVIEW(dev_priv))
                crtc_state->wm = wm_state;

diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index 74c1860..17649f1 100644 (file)
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -753,6 +753,7 @@ struct intel_crtc_state {
        struct intel_link_m_n fdi_m_n;
 
        bool ips_enabled;
+       bool ips_force_disable;
 
        bool enable_fbc;
 

diff --git a/drivers/gpu/drm/i915/intel_pipe_crc.c b/drivers/gpu/drm/i915/intel_pipe_crc.c
index 8fbd2bd..4e22bb9 100644 (file)
--- a/drivers/gpu/drm/i915/intel_pipe_crc.c
+++ b/drivers/gpu/drm/i915/intel_pipe_crc.c
@@ -506,8 +506,8 @@ static int ilk_pipe_crc_ctl_reg(enum intel_pipe_crc_source *source,
        return 0;
 }
 
-static void hsw_trans_edp_pipe_A_crc_wa(struct drm_i915_private *dev_priv,
-                                       bool enable)
+static void hsw_pipe_A_crc_wa(struct drm_i915_private *dev_priv,
+                             bool enable)
 {
        struct drm_device *dev = &dev_priv->drm;
        struct intel_crtc *crtc = intel_get_crtc_for_pipe(dev_priv, PIPE_A);
@@ -533,10 +533,24 @@ retry:
                goto put_state;
        }
 
-       pipe_config->pch_pfit.force_thru = enable;
-       if (pipe_config->cpu_transcoder == TRANSCODER_EDP &&
-           pipe_config->pch_pfit.enabled != enable)
-               pipe_config->base.connectors_changed = true;
+       if (HAS_IPS(dev_priv)) {
+               /*
+                * When IPS gets enabled, the pipe CRC changes. Since IPS gets
+                * enabled and disabled dynamically based on package C states,
+                * user space can't make reliable use of the CRCs, so let's just
+                * completely disable it.
+                */
+               pipe_config->ips_force_disable = enable;
+               if (pipe_config->ips_enabled == enable)
+                       pipe_config->base.connectors_changed = true;
+       }
+
+       if (IS_HASWELL(dev_priv)) {
+               pipe_config->pch_pfit.force_thru = enable;
+               if (pipe_config->cpu_transcoder == TRANSCODER_EDP &&
+                   pipe_config->pch_pfit.enabled != enable)
+                       pipe_config->base.connectors_changed = true;
+       }
 
        ret = drm_atomic_commit(state);
 
@@ -570,8 +584,9 @@ static int ivb_pipe_crc_ctl_reg(struct drm_i915_private *dev_priv,
                *val = PIPE_CRC_ENABLE | PIPE_CRC_SOURCE_SPRITE_IVB;
                break;
        case INTEL_PIPE_CRC_SOURCE_PF:
-               if (IS_HASWELL(dev_priv) && pipe == PIPE_A)
-                       hsw_trans_edp_pipe_A_crc_wa(dev_priv, true);
+               if ((IS_HASWELL(dev_priv) ||
+                    IS_BROADWELL(dev_priv)) && pipe == PIPE_A)
+                       hsw_pipe_A_crc_wa(dev_priv, true);
 
                *val = PIPE_CRC_ENABLE | PIPE_CRC_SOURCE_PF_IVB;
                break;
@@ -606,7 +621,6 @@ static int pipe_crc_set_source(struct drm_i915_private *dev_priv,
                               enum intel_pipe_crc_source source)
 {
        struct intel_pipe_crc *pipe_crc = &dev_priv->pipe_crc[pipe];
-       struct intel_crtc *crtc = intel_get_crtc_for_pipe(dev_priv, pipe);
        enum intel_display_power_domain power_domain;
        u32 val = 0; /* shut up gcc */
        int ret;
@@ -643,14 +657,6 @@ static int pipe_crc_set_source(struct drm_i915_private *dev_priv,
                        goto out;
                }
 
-               /*
-                * When IPS gets enabled, the pipe CRC changes. Since IPS gets
-                * enabled and disabled dynamically based on package C states,
-                * user space can't make reliable use of the CRCs, so let's just
-                * completely disable it.
-                */
-               hsw_disable_ips(crtc);
-
                spin_lock_irq(&pipe_crc->lock);
                kfree(pipe_crc->entries);
                pipe_crc->entries = entries;
@@ -691,10 +697,9 @@ static int pipe_crc_set_source(struct drm_i915_private *dev_priv,
                        g4x_undo_pipe_scramble_reset(dev_priv, pipe);
                else if (IS_VALLEYVIEW(dev_priv) || IS_CHERRYVIEW(dev_priv))
                        vlv_undo_pipe_scramble_reset(dev_priv, pipe);
-               else if (IS_HASWELL(dev_priv) && pipe == PIPE_A)
-                       hsw_trans_edp_pipe_A_crc_wa(dev_priv, false);
-
-               hsw_enable_ips(crtc);
+               else if ((IS_HASWELL(dev_priv) ||
+                         IS_BROADWELL(dev_priv)) && pipe == PIPE_A)
+                       hsw_pipe_A_crc_wa(dev_priv, false);
        }
 
        ret = 0;
@@ -935,16 +940,6 @@ int intel_crtc_set_crc_source(struct drm_crtc *crtc, const char *source_name,
        if (ret != 0)
                goto out;
 
-       if (source) {
-               /*
-                * When IPS gets enabled, the pipe CRC changes. Since IPS gets
-                * enabled and disabled dynamically based on package C states,
-                * user space can't make reliable use of the CRCs, so let's just
-                * completely disable it.
-                */
-               hsw_disable_ips(intel_crtc);
-       }
-
        I915_WRITE(PIPE_CRC_CTL(crtc->index), val);
        POSTING_READ(PIPE_CRC_CTL(crtc->index));
 
@@ -953,8 +948,9 @@ int intel_crtc_set_crc_source(struct drm_crtc *crtc, const char *source_name,
                        g4x_undo_pipe_scramble_reset(dev_priv, crtc->index);
                else if (IS_VALLEYVIEW(dev_priv) || IS_CHERRYVIEW(dev_priv))
                        vlv_undo_pipe_scramble_reset(dev_priv, crtc->index);
-               else if (IS_HASWELL(dev_priv) && crtc->index == PIPE_A)
-                       hsw_trans_edp_pipe_A_crc_wa(dev_priv, false);
+               else if ((IS_HASWELL(dev_priv) ||
+                         IS_BROADWELL(dev_priv)) && crtc->index == PIPE_A)
+                       hsw_pipe_A_crc_wa(dev_priv, false);
 
                hsw_enable_ips(intel_crtc);
        }