[PATCH v3 1/5] drm/i915: take display port power domain in DP HPD handler

Imre Deak
2014-08-18T11:42:48Z

Ville noticed that we can call ibx_digital_port_connected() which accesses
the HW without holding any power well/runtime pm reference. Fix this by
holding a display port power domain reference around the whole hpd_pulse
handler.

Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
---
drivers/gpu/drm/i915/intel_dp.c | 19 ++++++++++++++-----
1 file changed, 14 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index ee3942f..a520188 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -4037,15 +4037,21 @@ bool
intel_dp_hpd_pulse(struct intel_digital_port *intel_dig_port, bool long_hpd)
{
struct intel_dp *intel_dp = &intel_dig_port->dp;
+ struct intel_encoder *intel_encoder = &intel_dig_port->base;
struct drm_device *dev = intel_dig_port->base.base.dev;
struct drm_i915_private *dev_priv = dev->dev_private;
- int ret;
+ enum intel_display_power_domain power_domain;
+ bool ret = true;
+
if (intel_dig_port->base.type != INTEL_OUTPUT_EDP)
intel_dig_port->base.type = INTEL_OUTPUT_DISPLAYPORT;

DRM_DEBUG_KMS("got hpd irq on port %d - %s\n", intel_dig_port->port,
long_hpd ? "long" : "short");

+ power_domain = intel_display_port_power_domain(intel_encoder);
+ intel_display_power_get(dev_priv, power_domain);
+
if (long_hpd) {
if (!ibx_digital_port_connected(dev_priv, intel_dig_port))
goto mst_fail;
@@ -4061,8 +4067,7 @@ intel_dp_hpd_pulse(struct intel_digital_port *intel_dig_port, bool long_hpd)

} else {
if (intel_dp->is_mst) {
- ret = intel_dp_check_mst_status(intel_dp);
- if (ret == -EINVAL)
+ if (intel_dp_check_mst_status(intel_dp) == -EINVAL)
goto mst_fail;
}

@@ -4076,7 +4081,8 @@ intel_dp_hpd_pulse(struct intel_digital_port *intel_dig_port, bool long_hpd)
drm_modeset_unlock(&dev->mode_config.connection_mutex);
}
}
- return false;
+ ret = false;
+ goto put_power;
mst_fail:
/* if we were in MST mode, and device is not there get out of MST mode */
if (intel_dp->is_mst) {
@@ -4084,7 +4090,10 @@ mst_fail:
intel_dp->is_mst = false;
drm_dp_mst_topology_mgr_set_mst(&intel_dp->mst_mgr, intel_dp->is_mst);
}
- return true;
+put_power:
+ intel_display_power_put(dev_priv, power_domain);
+
+ return ret;
}

/* Return which DP Port should be selected for Transcoder DP control */