This patch checks for changes in sink count between short pulse
hpds and forces full detect when there is a change.
This will allow both detection of hotplug and unplug of panels
through dongles that give only short pulse for such events.
v2: changed variable type from u8 to bool (Jani)
return immediately if perform_full_detect is set(Siva)
v3: changed method of determining full detection from using
pointer to return code (Siva)
v4: changed comments to indicate meaning of return value of
intel_dp_short_pulse and explain the use of return value
from intel_dp_get_dpcd in intel_dp_short_pulse (Ander)
Tested-by: Nathan D Ciobanu <nathan.d.ciobanu@xxxxxxxxx>
Signed-off-by: Sivakumar Thulasimani <sivakumar.thulasimani@xxxxxxxxx>
Signed-off-by: Shubhangi Shrivastava <shubhangi.shrivastava@xxxxxxxxx>
Reviewed-by: Ander Conselvan de Oliveira <conselvan2@xxxxxxxxx>
---
drivers/gpu/drm/i915/intel_dp.c | 33 +++++++++++++++++++++++++++------
1 file changed, 27 insertions(+), 6 deletions(-)
diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index 9b2b96f..538bc02 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -4273,12 +4273,19 @@ intel_dp_check_link_status(struct intel_dp *intel_dp)
* 2. Configure link according to Receiver Capabilities
* 3. Use Link Training from 2.5.3.3 and 3.5.1.3
* 4. Check link status on receipt of hot-plug interrupt
+ *
+ * intel_dp_short_pulse - handles short pulse interrupts
+ * when full detection is not required.
+ * Returns %true if short pulse is handled and full detection
+ * is NOT required and %false otherwise.
*/
-static void
+static bool
intel_dp_short_pulse(struct intel_dp *intel_dp)
{
struct drm_device *dev = intel_dp_to_dev(intel_dp);
u8 sink_irq_vector;
+ u8 old_sink_count = intel_dp->sink_count;
+ bool ret;
/*
* Clearing compliance test variables to allow capturing
@@ -4288,9 +4295,17 @@ intel_dp_short_pulse(struct intel_dp *intel_dp)
intel_dp->compliance_test_type = 0;
intel_dp->compliance_test_data = 0;
- /* Now read the DPCD to see if it's actually running */
- if (!intel_dp_get_dpcd(intel_dp)) {
- return;
+ /*
+ * Now read the DPCD to see if it's actually running
+ * If the current value of sink count doesn't match with
+ * the value that was stored earlier or dpcd read failed
+ * we need to do full detection
+ */
+ ret = intel_dp_get_dpcd(intel_dp);
+
+ if ((old_sink_count != intel_dp->sink_count) || !ret) {
+ /* No need to proceed if we are going to do full detect */
+ return false;
}
/* Try to read the source of the interrupt */
@@ -4310,6 +4325,8 @@ intel_dp_short_pulse(struct intel_dp *intel_dp)
drm_modeset_lock(&dev->mode_config.connection_mutex, NULL);
intel_dp_check_link_status(intel_dp);
drm_modeset_unlock(&dev->mode_config.connection_mutex);
+
+ return true;
}
/* XXX this is probably wrong for multiple downstream ports */
@@ -5043,8 +5060,12 @@ intel_dp_hpd_pulse(struct intel_digital_port *intel_dig_port, bool long_hpd)
}
}
- if (!intel_dp->is_mst)
- intel_dp_short_pulse(intel_dp);
+ if (!intel_dp->is_mst) {
+ if (!intel_dp_short_pulse(intel_dp)) {
+ intel_dp_long_pulse(intel_dp->attached_connector);
+ goto put_power;
+ }
+ }
}
ret = IRQ_HANDLED;
--
2.6.1
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