drm/i915/dp: cache eDP DPCD data
Cache the first 4 bytes of DPCD data in the eDP case. It's unlikely to
change and can save us some trouble at link training time.
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 6d49a9f..84e33ae 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -350,6 +350,7 @@
int bpp;
struct edp_power_seq pps;
} edp;
+ bool no_aux_handshake;
struct notifier_block lid_notifier;
diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index 944dfe1..7fa8282 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -1724,6 +1724,26 @@
intel_dp_i2c_init(intel_dp, intel_connector, name);
+ /* Cache some DPCD data in the eDP case */
+ if (is_edp(intel_dp)) {
+ int ret;
+ bool was_on;
+
+ was_on = ironlake_edp_panel_on(intel_dp);
+ ret = intel_dp_aux_native_read(intel_dp, DP_DPCD_REV,
+ intel_dp->dpcd,
+ sizeof(intel_dp->dpcd));
+ if (ret == sizeof(intel_dp->dpcd)) {
+ if (intel_dp->dpcd[0] >= 0x11)
+ dev_priv->no_aux_handshake = intel_dp->dpcd[3] &
+ DP_NO_AUX_HANDSHAKE_LINK_TRAINING;
+ } else {
+ DRM_ERROR("failed to retrieve link info\n");
+ }
+ if (!was_on)
+ ironlake_edp_panel_off(dev);
+ }
+
intel_encoder->hot_plug = intel_dp_hot_plug;
if (is_edp(intel_dp)) {