[PATCH 04/13] drm/i915/dmc_wl: Get wakelock when disabling dynamic DC states

[Gustavo Sousa]

Bspec says that disabling dynamic DC states require taking the DMC
wakelock to cause an DC exit before writing to DC_STATE_EN. Implement
that.

In fact, testing on PTL revealed we end up failing to exit DC5/6 without
this step.

Bspec: 71583
Signed-off-by: Gustavo Sousa <gustavo.so...@intel.com>
---
 .../drm/i915/display/intel_display_power_well.c    | 10 +++++++---
 drivers/gpu/drm/i915/display/intel_dmc_wl.c        | 14 ++++++++++++--
 drivers/gpu/drm/i915/display/intel_dmc_wl.h        |  2 ++
 3 files changed, 21 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_display_power_well.c 
b/drivers/gpu/drm/i915/display/intel_display_power_well.c
index adaf7cf3a33b..e8946ce86aaa 100644
--- a/drivers/gpu/drm/i915/display/intel_display_power_well.c
+++ b/drivers/gpu/drm/i915/display/intel_display_power_well.c
@@ -987,10 +987,14 @@ void gen9_disable_dc_states(struct intel_display *display)
                return;
        }
 
-       gen9_set_dc_state(display, DC_STATE_DISABLE);
-
-       if (!HAS_DISPLAY(display))
+       if (HAS_DISPLAY(display)) {
+               intel_dmc_wl_get_noreg(display);
+               gen9_set_dc_state(display, DC_STATE_DISABLE);
+               intel_dmc_wl_put_noreg(display);
+       } else {
+               gen9_set_dc_state(display, DC_STATE_DISABLE);
                return;
+       }
 
        intel_dmc_wl_disable(display);
 
diff --git a/drivers/gpu/drm/i915/display/intel_dmc_wl.c 
b/drivers/gpu/drm/i915/display/intel_dmc_wl.c
index c298aef89449..5ed610c9be39 100644
--- a/drivers/gpu/drm/i915/display/intel_dmc_wl.c
+++ b/drivers/gpu/drm/i915/display/intel_dmc_wl.c
@@ -194,7 +194,7 @@ void intel_dmc_wl_get(struct intel_display *display, 
i915_reg_t reg)
        if (!__intel_dmc_wl_supported(display))
                return;
 
-       if (!intel_dmc_wl_check_range(reg.reg))
+       if (i915_mmio_reg_valid(reg) && !intel_dmc_wl_check_range(reg.reg))
                return;
 
        spin_lock_irqsave(&wl->lock, flags);
@@ -246,7 +246,7 @@ void intel_dmc_wl_put(struct intel_display *display, 
i915_reg_t reg)
        if (!__intel_dmc_wl_supported(display))
                return;
 
-       if (!intel_dmc_wl_check_range(reg.reg))
+       if (i915_mmio_reg_valid(reg) && !intel_dmc_wl_check_range(reg.reg))
                return;
 
        spin_lock_irqsave(&wl->lock, flags);
@@ -267,3 +267,13 @@ void intel_dmc_wl_put(struct intel_display *display, 
i915_reg_t reg)
 out_unlock:
        spin_unlock_irqrestore(&wl->lock, flags);
 }
+
+void intel_dmc_wl_get_noreg(struct intel_display *display)
+{
+       intel_dmc_wl_get(display, INVALID_MMIO_REG);
+}
+
+void intel_dmc_wl_put_noreg(struct intel_display *display)
+{
+       intel_dmc_wl_put(display, INVALID_MMIO_REG);
+}
diff --git a/drivers/gpu/drm/i915/display/intel_dmc_wl.h 
b/drivers/gpu/drm/i915/display/intel_dmc_wl.h
index adab51208d0a..9aa72a4bf153 100644
--- a/drivers/gpu/drm/i915/display/intel_dmc_wl.h
+++ b/drivers/gpu/drm/i915/display/intel_dmc_wl.h
@@ -27,5 +27,7 @@ void intel_dmc_wl_enable(struct intel_display *display);
 void intel_dmc_wl_disable(struct intel_display *display);
 void intel_dmc_wl_get(struct intel_display *display, i915_reg_t reg);
 void intel_dmc_wl_put(struct intel_display *display, i915_reg_t reg);
+void intel_dmc_wl_get_noreg(struct intel_display *display);
+void intel_dmc_wl_put_noreg(struct intel_display *display);
 
 #endif /* __INTEL_WAKELOCK_H__ */
-- 
2.47.0