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path: root/drivers/gpu/drm/i915/intel_dp.c
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Diffstat (limited to 'drivers/gpu/drm/i915/intel_dp.c')
-rw-r--r--drivers/gpu/drm/i915/intel_dp.c62
1 files changed, 55 insertions, 7 deletions
diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index 300f64b4238b..864417cffe9a 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -479,6 +479,7 @@ intel_dp_i2c_aux_ch(struct i2c_adapter *adapter, int mode,
uint16_t address = algo_data->address;
uint8_t msg[5];
uint8_t reply[2];
+ unsigned retry;
int msg_bytes;
int reply_bytes;
int ret;
@@ -513,14 +514,33 @@ intel_dp_i2c_aux_ch(struct i2c_adapter *adapter, int mode,
break;
}
- for (;;) {
- ret = intel_dp_aux_ch(intel_dp,
- msg, msg_bytes,
- reply, reply_bytes);
+ for (retry = 0; retry < 5; retry++) {
+ ret = intel_dp_aux_ch(intel_dp,
+ msg, msg_bytes,
+ reply, reply_bytes);
if (ret < 0) {
DRM_DEBUG_KMS("aux_ch failed %d\n", ret);
return ret;
}
+
+ switch (reply[0] & AUX_NATIVE_REPLY_MASK) {
+ case AUX_NATIVE_REPLY_ACK:
+ /* I2C-over-AUX Reply field is only valid
+ * when paired with AUX ACK.
+ */
+ break;
+ case AUX_NATIVE_REPLY_NACK:
+ DRM_DEBUG_KMS("aux_ch native nack\n");
+ return -EREMOTEIO;
+ case AUX_NATIVE_REPLY_DEFER:
+ udelay(100);
+ continue;
+ default:
+ DRM_ERROR("aux_ch invalid native reply 0x%02x\n",
+ reply[0]);
+ return -EREMOTEIO;
+ }
+
switch (reply[0] & AUX_I2C_REPLY_MASK) {
case AUX_I2C_REPLY_ACK:
if (mode == MODE_I2C_READ) {
@@ -528,17 +548,20 @@ intel_dp_i2c_aux_ch(struct i2c_adapter *adapter, int mode,
}
return reply_bytes - 1;
case AUX_I2C_REPLY_NACK:
- DRM_DEBUG_KMS("aux_ch nack\n");
+ DRM_DEBUG_KMS("aux_i2c nack\n");
return -EREMOTEIO;
case AUX_I2C_REPLY_DEFER:
- DRM_DEBUG_KMS("aux_ch defer\n");
+ DRM_DEBUG_KMS("aux_i2c defer\n");
udelay(100);
break;
default:
- DRM_ERROR("aux_ch invalid reply 0x%02x\n", reply[0]);
+ DRM_ERROR("aux_i2c invalid reply 0x%02x\n", reply[0]);
return -EREMOTEIO;
}
}
+
+ DRM_ERROR("too many retries, giving up\n");
+ return -EREMOTEIO;
}
static int
@@ -1376,6 +1399,9 @@ intel_dp_link_down(struct intel_dp *intel_dp)
struct drm_i915_private *dev_priv = dev->dev_private;
uint32_t DP = intel_dp->DP;
+ if ((I915_READ(intel_dp->output_reg) & DP_PORT_EN) == 0)
+ return;
+
DRM_DEBUG_KMS("\n");
if (is_edp(intel_dp)) {
@@ -1398,6 +1424,28 @@ intel_dp_link_down(struct intel_dp *intel_dp)
if (is_edp(intel_dp))
DP |= DP_LINK_TRAIN_OFF;
+
+ if (!HAS_PCH_CPT(dev) &&
+ I915_READ(intel_dp->output_reg) & DP_PIPEB_SELECT) {
+ struct intel_crtc *intel_crtc = to_intel_crtc(intel_dp->base.base.crtc);
+ /* Hardware workaround: leaving our transcoder select
+ * set to transcoder B while it's off will prevent the
+ * corresponding HDMI output on transcoder A.
+ *
+ * Combine this with another hardware workaround:
+ * transcoder select bit can only be cleared while the
+ * port is enabled.
+ */
+ DP &= ~DP_PIPEB_SELECT;
+ I915_WRITE(intel_dp->output_reg, DP);
+
+ /* Changes to enable or select take place the vblank
+ * after being written.
+ */
+ intel_wait_for_vblank(intel_dp->base.base.dev,
+ intel_crtc->pipe);
+ }
+
I915_WRITE(intel_dp->output_reg, DP & ~DP_PORT_EN);
POSTING_READ(intel_dp->output_reg);
}