On 8/26/2015 5:21 PM, Ville Syrjälä wrote:
On Tue, Aug 25, 2015 at 05:20:36PM +0530, Sivakumar Thulasimani wrote:
From: "Thulasimani,Sivakumar" <sivakumar.thulasimani@xxxxxxxxx>
This patch reads sink_count dpcd always and removes its
read operation based on values in downstream port dpcd. Also
we should read it irrespective of current status of sink.
SINK_COUNT dpcd is not dependent on DOWNSTREAM_PORT_PRESENT dpcd.
SINK_COUNT denotes if a display is attached, while
DOWNSTREAM_PORT_PRESET indicates how many ports are available
in the dongle where display can be attached. so it is possible
for sink count to change irrespective of value in downstream
port dpcd.
Here is a table of possible values and scenarios
sink_count downstream_port
present
0 0 no display is attached
0 1 dongle is connected without display
1 0 display connected directly
1 1 display connected through dongle
Signed-off-by: Sivakumar Thulasimani <sivakumar.thulasimani@xxxxxxxxx>
---
drivers/gpu/drm/i915/intel_dp.c | 33 ++++++++++++++-------------------
1 file changed, 14 insertions(+), 19 deletions(-)
diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index 8a66a44..9e4e27d 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -3898,6 +3898,7 @@ intel_dp_get_dpcd(struct intel_dp *intel_dp)
struct drm_device *dev = dig_port->base.base.dev;
struct drm_i915_private *dev_priv = dev->dev_private;
uint8_t rev;
+ uint8_t reg;
if (intel_dp_dpcd_read_wake(&intel_dp->aux, 0x000, intel_dp->dpcd,
sizeof(intel_dp->dpcd)) < 0)
@@ -3908,6 +3909,13 @@ intel_dp_get_dpcd(struct intel_dp *intel_dp)
if (intel_dp->dpcd[DP_DPCD_REV] == 0)
return false; /* DPCD not present */
+ if (intel_dp_dpcd_read_wake(&intel_dp->aux, DP_SINK_COUNT,
+ ®, 1) < 0)
+ return false;
+
+ if (!DP_GET_SINK_COUNT(reg))
+ return false;
+
/* Check if the panel supports PSR */
memset(intel_dp->psr_dpcd, 0, sizeof(intel_dp->psr_dpcd));
if (is_edp(intel_dp)) {
@@ -4374,12 +4382,6 @@ intel_dp_check_link_status(struct intel_dp *intel_dp)
WARN_ON(!drm_modeset_is_locked(&dev->mode_config.connection_mutex));
- if (!intel_encoder->base.crtc)
- return;
-
- if (!to_intel_crtc(intel_encoder->base.crtc)->active)
- return;
-
I don't like trying to overload intel_dp_check_link_status() to do other
stuff besides link retraining. The sink irq stuff already snuck in
somehow, but I think we should pull it out and try to make the function
names match what they do.
The entire DP hpd locking also needs more though. We now grab the
connection_mutex for the retraining to prevent racing against modeset,
but it doesn't prevent racing against ->detect(). And for MST we take
no locks whatsoever, even for the retraining (I have a patch for that
that I'll send out soon).
Agree, i am still thinking on how to extract the Automated test request
part so
we can avoid having same code twice in intel_dp_detect() and in
intel_dp_check_link_status. if your patch also cleans up this function i can
rebase on top of it.
/* Try to read receiver status if the link appears to be up */
if (!intel_dp_get_link_status(intel_dp, link_status)) {
return;
@@ -4390,6 +4392,12 @@ intel_dp_check_link_status(struct intel_dp *intel_dp)
return;
}
+ if (!intel_encoder->base.crtc)
+ return;
+
+ if (!to_intel_crtc(intel_encoder->base.crtc)->active)
+ return;
+
/* Try to read the source of the interrupt */
if (intel_dp->dpcd[DP_DPCD_REV] >= 0x11 &&
intel_dp_get_sink_irq(intel_dp, &sink_irq_vector)) {
@@ -4427,19 +4435,6 @@ intel_dp_detect_dpcd(struct intel_dp *intel_dp)
if (!(dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DWN_STRM_PORT_PRESENT))
return connector_status_connected;
- /* If we're HPD-aware, SINK_COUNT changes dynamically */
- if (intel_dp->dpcd[DP_DPCD_REV] >= 0x11 &&
- intel_dp->downstream_ports[0] & DP_DS_PORT_HPD) {
- uint8_t reg;
-
- if (intel_dp_dpcd_read_wake(&intel_dp->aux, DP_SINK_COUNT,
- ®, 1) < 0)
- return connector_status_unknown;
-
- return DP_GET_SINK_COUNT(reg) ? connector_status_connected
- : connector_status_disconnected;
- }
-
/* If no HPD, poke DDC gently */
if (drm_probe_ddc(&intel_dp->aux.ddc))
return connector_status_connected;
--
1.7.9.5
--
regards,
Sivakumar
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