From: Paulo Zanoni <paulo.r.zanoni at intel.com>
If the power well is disabled, we should not try to read its
registers, otherwise we'll get "unclaimed register" messages.
V2: Don't check whether the power well is enabled or not, just check
whether we asked it to be enabled or not: if we asked to disable the
power well, don't use the registers on it, even if it's still enabled.
V3: Fix bug that breaks all non-Haswell machines.
Signed-off-by: Paulo Zanoni <paulo.r.zanoni at intel.com>
---
drivers/gpu/drm/i915/intel_display.c | 12 +++++++++---
1 file changed, 9 insertions(+), 3 deletions(-)
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 56c51dd..de3efdd 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -1214,9 +1214,15 @@ void assert_pipe(struct drm_i915_private *dev_priv,
if (pipe == PIPE_A && dev_priv->quirks & QUIRK_PIPEA_FORCE)
state = true;
- reg = PIPECONF(cpu_transcoder);
- val = I915_READ(reg);
- cur_state = !!(val & PIPECONF_ENABLE);
+ if (IS_HASWELL(dev_priv->dev) && cpu_transcoder != TRANSCODER_EDP &&
+ !(I915_READ(HSW_PWR_WELL_DRIVER) & HSW_PWR_WELL_ENABLE)) {
+ cur_state = false;
+ } else {
+ reg = PIPECONF(cpu_transcoder);
+ val = I915_READ(reg);
+ cur_state = !!(val & PIPECONF_ENABLE);
+ }
+
WARN(cur_state != state,
"pipe %c assertion failure (expected %s, current %s)\n",
pipe_name(pipe), state_string(state), state_string(cur_state));
--
1.7.10.4
