[PATCH 1/5] drm/i915: don't write powered down IRQ registers on Gen 8

Paulo Zanoni
2014-07-04T14:50:45Z

From: Paulo Zanoni <paulo.r.zanoni@intel.com>

If we enable unclaimed register reporting on Gen 8, we will discover
that the IRQ registers for pipes B and C are also on the power well,
so writes to them when the power well is disabled result in unclaimed
register errors.

Also, hsw_power_well_post_enable() already takes care of re-enabling
them once the power well is enabled.

Testcase: igt/pm_rpm/rte
Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
---
drivers/gpu/drm/i915/i915_irq.c | 11 ++++++++---
1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
index 1c1ec22..2e116e9d 100644
--- a/drivers/gpu/drm/i915/i915_irq.c
+++ b/drivers/gpu/drm/i915/i915_irq.c
@@ -3193,7 +3193,9 @@ static void gen8_irq_reset(struct drm_device *dev)
gen8_gt_irq_reset(dev_priv);

for_each_pipe(pipe)
- GEN8_IRQ_RESET_NDX(DE_PIPE, pipe);
+ if (intel_display_power_enabled(dev_priv,
+ POWER_DOMAIN_PIPE(pipe)))
+ GEN8_IRQ_RESET_NDX(DE_PIPE, pipe);

GEN5_IRQ_RESET(GEN8_DE_PORT_);
GEN5_IRQ_RESET(GEN8_DE_MISC_);
@@ -3526,8 +3528,11 @@ static void gen8_de_irq_postinstall(struct drm_i915_private *dev_priv)
dev_priv->de_irq_mask[PIPE_C] = ~de_pipe_masked;

for_each_pipe(pipe)
- GEN8_IRQ_INIT_NDX(DE_PIPE, pipe, dev_priv->de_irq_mask[pipe],
- de_pipe_enables);
+ if (intel_display_power_enabled(dev_priv,
+ POWER_DOMAIN_PIPE(pipe)))
+ GEN8_IRQ_INIT_NDX(DE_PIPE, pipe,
+ dev_priv->de_irq_mask[pipe],
+ de_pipe_enables);

GEN5_IRQ_INIT(GEN8_DE_PORT_, ~GEN8_AUX_CHANNEL_A, GEN8_AUX_CHANNEL_A);
}
--
2.0.0