[PATCH v3 5/6] drm/i915: Apply the PPS register unlock workaround more consistently

Imre Deak
2016-08-09T18:59:21Z

Atm, we apply this workaround somewhat inconsistently at the following
points: driver loading, LVDS init, eDP PPS init, system resume. As this
workaround also affects registers other than PPS (timing, PLL) a more
consistent way is to apply it early after the PPS HW context is known to
be lost: driver loading, system resume and on VLV/CHV/BXT when turning
on power domains.

This is needed by the next patch that removes saving/restoring of the
PP_CONTROL register.

This also removes the incorrect programming of the workaround on HSW+
PCH platforms which don't have the register locking mechanism.

v2: (Ville)
- Don't apply the workaround on BXT.
- Simplify platform checks using HAS_DDI().
v3:
- Move the call of intel_pps_unlock_regs_wa() to the more
logical vlv_display_power_well_init() (also fixing CHV) (Ville).

Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
---
drivers/gpu/drm/i915/i915_drv.c | 1 +
drivers/gpu/drm/i915/intel_display.c | 26 ++++++++++++++++++++++++++
drivers/gpu/drm/i915/intel_dp.c | 3 ++-
drivers/gpu/drm/i915/intel_drv.h | 1 +
drivers/gpu/drm/i915/intel_lvds.c | 8 --------
drivers/gpu/drm/i915/intel_runtime_pm.c | 4 ++++
6 files changed, 34 insertions(+), 9 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index 8cfc264..0fcd1c0 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -1560,6 +1560,7 @@ static int i915_drm_resume(struct drm_device *dev)
i915_gem_resume(dev);

i915_restore_state(dev);
+ intel_pps_unlock_regs_wa(dev_priv);
intel_opregion_setup(dev_priv);

intel_init_pch_refclk(dev);
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 3d5fd06..bcbf277 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -14635,6 +14635,30 @@ static bool intel_crt_present(struct drm_device *dev)
return true;
}

+void intel_pps_unlock_regs_wa(struct drm_i915_private *dev_priv)
+{
+ int pps_num;
+ int pps_idx;
+
+ if (HAS_DDI(dev_priv))
+ return;
+ /*
+ * This w/a is needed at least on CPT/PPT, but to be sure apply it
+ * everywhere where registers can be write protected.
+ */
+ if (IS_VALLEYVIEW(dev_priv) || IS_CHERRYVIEW(dev_priv))
+ pps_num = 2;
+ else
+ pps_num = 1;
+
+ for (pps_idx = 0; pps_idx < pps_num; pps_idx++) {
+ u32 val = I915_READ(PP_CONTROL(pps_idx));
+
+ val = (val & ~PANEL_UNLOCK_MASK) | PANEL_UNLOCK_REGS;
+ I915_WRITE(PP_CONTROL(pps_idx), val);
+ }
+}
+
static void intel_pps_init(struct drm_i915_private *dev_priv)
{
if (HAS_PCH_SPLIT(dev_priv) || IS_BROXTON(dev_priv))
@@ -14643,6 +14667,8 @@ static void intel_pps_init(struct drm_i915_private *dev_priv)
dev_priv->pps_mmio_base = VLV_PPS_BASE;
else
dev_priv->pps_mmio_base = PPS_BASE;
+
+ intel_pps_unlock_regs_wa(dev_priv);
}

static void intel_setup_outputs(struct drm_device *dev)
diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index 2ef7b14..3d3d3fb 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -1829,7 +1829,8 @@ static u32 ironlake_get_pp_control(struct intel_dp *intel_dp)
lockdep_assert_held(&dev_priv->pps_mutex);

control = I915_READ(_pp_ctrl_reg(intel_dp));
- if (!IS_BROXTON(dev)) {
+ if (WARN_ON(!HAS_DDI(dev_priv) &&
+ (control & PANEL_UNLOCK_MASK) != PANEL_UNLOCK_REGS)) {
control &= ~PANEL_UNLOCK_MASK;
control |= PANEL_UNLOCK_REGS;
}
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index c29a429..cbce786 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -1159,6 +1159,7 @@ void intel_mark_busy(struct drm_i915_private *dev_priv);
void intel_mark_idle(struct drm_i915_private *dev_priv);
void intel_crtc_restore_mode(struct drm_crtc *crtc);
int intel_display_suspend(struct drm_device *dev);
+void intel_pps_unlock_regs_wa(struct drm_i915_private *dev_priv);
void intel_encoder_destroy(struct drm_encoder *encoder);
int intel_connector_init(struct intel_connector *);
struct intel_connector *intel_connector_alloc(void);
diff --git a/drivers/gpu/drm/i915/intel_lvds.c b/drivers/gpu/drm/i915/intel_lvds.c
index e79fae4..668eabb 100644
--- a/drivers/gpu/drm/i915/intel_lvds.c
+++ b/drivers/gpu/drm/i915/intel_lvds.c
@@ -978,14 +978,6 @@ void intel_lvds_init(struct drm_device *dev)
int pipe;
u8 pin;

- /*
- * Unlock registers and just leave them unlocked. Do this before
- * checking quirk lists to avoid bogus WARNINGs.
- */
- if (HAS_PCH_SPLIT(dev_priv) || INTEL_GEN(dev_priv) <= 4)
- I915_WRITE(PP_CONTROL(0),
- I915_READ(PP_CONTROL(0)) | PANEL_UNLOCK_REGS);
-
if (!intel_lvds_supported(dev))
return;

diff --git a/drivers/gpu/drm/i915/intel_runtime_pm.c b/drivers/gpu/drm/i915/intel_runtime_pm.c
index 1c603bb..d659d6f 100644
--- a/drivers/gpu/drm/i915/intel_runtime_pm.c
+++ b/drivers/gpu/drm/i915/intel_runtime_pm.c
@@ -592,6 +592,8 @@ void bxt_disable_dc9(struct drm_i915_private *dev_priv)
DRM_DEBUG_KMS("Disabling DC9\n");

gen9_set_dc_state(dev_priv, DC_STATE_DISABLE);
+
+ intel_pps_unlock_regs_wa(dev_priv);
}

static void assert_csr_loaded(struct drm_i915_private *dev_priv)
@@ -1121,6 +1123,8 @@ static void vlv_display_power_well_init(struct drm_i915_private *dev_priv)
}

i915_redisable_vga_power_on(&dev_priv->drm);
+
+ intel_pps_unlock_regs_wa(dev_priv);
}

static void vlv_display_power_well_deinit(struct drm_i915_private *dev_priv)
--
2.5.0