[PATCH 06/12] drm/i915: Update intel_dp_hpd_pulse() for non-MST operation

Todd Previte
2015-04-15T17:16:03Z

Update the hot plug function to handle the SST case. Instead of placing
the SST case within the long/short pulse block, it is now handled after
determining that MST mode is not in use. This way, the topology management
layer can handle any MST-related operations while SST operations are still
correctly handled afterwards.

This patch also corrects the problem of SST mode only being handled in the
case of a short (0.5ms - 1.0ms) HPD pulse. For compliance testing purposes
both short and long pulses are used by the different tests, thus both cases
need to be addressed for SST.

This patch replaces [PATCH 10/10] drm/i915: Fix intel_dp_hot_plug() in the
previous compliance testing patch sequence. Review feedback on that patch
indicated that updating intel_dp_hot_plug() was not the correct place for
the test handler.

For the SST case, the main stream is disabled for long HPD pulses as this
generally indicates either a connect/disconnect event or link failure. For
a number of case in compliance testing, the source is required to disable
the main link upon detection of a long HPD.

V2:
- N/A
V3:
- Place the SST mode link status check into the mst_fail case
- Remove obsolete comment regarding SST mode operation
- Removed an erroneous line of code that snuck in during rebasing
V4:
- Added a disable of the main stream (DP transport) for the long pulse case
for SST to support compliance testing
V5:
- Reworked SST handling to support tests 4.2.2.7 and 4.2.2.8
V6:
- Reformatted a comment
V7:
- Moved a comment again that was inadvertently moved
- Updated the code to properly handle all permutations of MST/SST and
short/long pulse.
- Adds a new 'connected' flag that prevents unnecessary operations when
the link is disconnected.
- Added a function to encapsulate detection of the HPD pin status in
in order to determine connected status
- Reformatted the if-statements in the function so the braces are
consistent for those with single statements after the if-statement
V8:
- Updated to account for long_hpd flag propagation

Signed-off-by: Todd Previte <tprevite@gmail.com>
---
drivers/gpu/drm/i915/intel_dp.c | 55 +++++++++++++++++++++++++---------------
drivers/gpu/drm/i915/intel_drv.h | 1 +
2 files changed, 35 insertions(+), 21 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index ee41e10..aa3b89d 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -4747,6 +4747,7 @@ intel_dp_hpd_pulse(struct intel_digital_port *intel_dig_port, bool long_hpd)
struct drm_i915_private *dev_priv = dev->dev_private;
enum intel_display_power_domain power_domain;
enum irqreturn ret = IRQ_NONE;
+ bool connected = false;

if (intel_dig_port->base.type != INTEL_OUTPUT_EDP)
intel_dig_port->base.type = INTEL_OUTPUT_DISPLAYPORT;
@@ -4770,19 +4771,15 @@ intel_dp_hpd_pulse(struct intel_digital_port *intel_dig_port, bool long_hpd)
power_domain = intel_display_port_power_domain(intel_encoder);
intel_display_power_get(dev_priv, power_domain);

+ connected = intel_dp_digital_port_connected(intel_dp);
+
if (long_hpd) {

- if (HAS_PCH_SPLIT(dev)) {
- if (!ibx_digital_port_connected(dev_priv, intel_dig_port))
- goto mst_fail;
- } else {
- if (g4x_digital_port_connected(dev, intel_dig_port) != 1)
- goto mst_fail;
- }
+ if (!connected)
+ goto mst_fail;

- if (!intel_dp_get_dpcd(intel_dp)) {
+ if (!intel_dp_get_dpcd(intel_dp))
goto mst_fail;
- }

intel_dp_probe_oui(intel_dp);

@@ -4790,20 +4787,9 @@ intel_dp_hpd_pulse(struct intel_digital_port *intel_dig_port, bool long_hpd)
goto mst_fail;

} else {
- if (intel_dp->is_mst) {
+ if (intel_dp->is_mst)
if (intel_dp_check_mst_status(intel_dp) == -EINVAL)
goto mst_fail;
- }
-
- if (!intel_dp->is_mst) {
- /*
- * we'll check the link status via the normal hot plug path later -
- * but for short hpds we should check it now
- */
- drm_modeset_lock(&dev->mode_config.connection_mutex, NULL);
- intel_dp_check_link_status(intel_dp, long_hpd);
- drm_modeset_unlock(&dev->mode_config.connection_mutex);
- }
}

ret = IRQ_HANDLED;
@@ -4817,6 +4803,15 @@ mst_fail:
drm_dp_mst_topology_mgr_set_mst(&intel_dp->mst_mgr, intel_dp->is_mst);
}
put_power:
+ /* SST mode - handle short/long pulses here */
+ if (!intel_dp->is_mst) {
+
+ drm_modeset_lock(&dev->mode_config.connection_mutex, NULL);
+ if (connected)
+ intel_dp_check_link_status(intel_dp, long_hpd);
+ drm_modeset_unlock(&dev->mode_config.connection_mutex);
+ ret = IRQ_HANDLED;
+ }
intel_display_power_put(dev_priv, power_domain);

return ret;
@@ -5803,3 +5798,21 @@ void intel_dp_mst_resume(struct drm_device *dev)
}
}
}
+
+bool intel_dp_digital_port_connected(struct intel_dp *intel_dp)
+{
+ struct intel_digital_port *intel_dig_port = dp_to_dig_port(intel_dp);
+ struct drm_device *dev = intel_dig_port->base.base.dev;
+ struct drm_i915_private *dev_priv = dev->dev_private;
+ bool connected = true;
+
+ if (HAS_PCH_SPLIT(dev)) {
+ if (!ibx_digital_port_connected(dev_priv, intel_dig_port))
+ connected = false;
+ } else {
+ if (g4x_digital_port_connected(dev, intel_dig_port) != 1)
+ connected = false;
+ }
+
+ return connected;
+}
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index a4675fa..accf08b 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -1173,6 +1173,7 @@ void intel_edp_drrs_disable(struct intel_dp *intel_dp);
void intel_edp_drrs_invalidate(struct drm_device *dev,
unsigned frontbuffer_bits);
void intel_edp_drrs_flush(struct drm_device *dev, unsigned frontbuffer_bits);
+bool intel_dp_digital_port_connected(struct intel_dp *intel_dp);

/* intel_dp_mst.c */
int intel_dp_mst_encoder_init(struct intel_digital_port *intel_dig_port, int conn_id);