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authorKeith Packard <keithp@keithp.com>2011-09-19 13:54:47 -0700
committerKeith Packard <keithp@keithp.com>2011-09-30 16:23:45 -0700
commit9b984daec45632c4c1ef6e628dca4d2bc8f544ed (patch)
tree93dc57e7d712dcf1be291b078308894ce01c1bc5 /drivers/gpu/drm/i915/intel_dp.c
parent47f0eb2234a2a1c790825393bbaccfadf82463d3 (diff)
downloadop-kernel-dev-9b984daec45632c4c1ef6e628dca4d2bc8f544ed.zip
op-kernel-dev-9b984daec45632c4c1ef6e628dca4d2bc8f544ed.tar.gz
drm/i915: Check eDP power when doing aux channel communications
Verify that the eDP VDD is on, either with the panel being on or with the VDD force-on bit being set. This demonstrates that in many instances, VDD is not on when needed, which leads to failed EDID communications. Signed-off-by: Keith Packard <keithp@keithp.com>
Diffstat (limited to 'drivers/gpu/drm/i915/intel_dp.c')
-rw-r--r--drivers/gpu/drm/i915/intel_dp.c22
1 files changed, 22 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index 3717fa6..1bf3258 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -279,6 +279,24 @@ intel_hrawclk(struct drm_device *dev)
}
}
+static void
+intel_dp_check_edp(struct intel_dp *intel_dp)
+{
+ struct drm_device *dev = intel_dp->base.base.dev;
+ struct drm_i915_private *dev_priv = dev->dev_private;
+ u32 pp_status, pp_control;
+ if (!is_edp(intel_dp))
+ return;
+ pp_status = I915_READ(PCH_PP_STATUS);
+ pp_control = I915_READ(PCH_PP_CONTROL);
+ if ((pp_status & PP_ON) == 0 && (pp_control & EDP_FORCE_VDD) == 0) {
+ WARN(1, "eDP powered off while attempting aux channel communication.\n");
+ DRM_DEBUG_KMS("Status 0x%08x Control 0x%08x\n",
+ pp_status,
+ I915_READ(PCH_PP_CONTROL));
+ }
+}
+
static int
intel_dp_aux_ch(struct intel_dp *intel_dp,
uint8_t *send, int send_bytes,
@@ -295,6 +313,7 @@ intel_dp_aux_ch(struct intel_dp *intel_dp,
uint32_t aux_clock_divider;
int try, precharge;
+ intel_dp_check_edp(intel_dp);
/* The clock divider is based off the hrawclk,
* and would like to run at 2MHz. So, take the
* hrawclk value and divide by 2 and use that
@@ -408,6 +427,7 @@ intel_dp_aux_native_write(struct intel_dp *intel_dp,
int msg_bytes;
uint8_t ack;
+ intel_dp_check_edp(intel_dp);
if (send_bytes > 16)
return -1;
msg[0] = AUX_NATIVE_WRITE << 4;
@@ -450,6 +470,7 @@ intel_dp_aux_native_read(struct intel_dp *intel_dp,
uint8_t ack;
int ret;
+ intel_dp_check_edp(intel_dp);
msg[0] = AUX_NATIVE_READ << 4;
msg[1] = address >> 8;
msg[2] = address & 0xff;
@@ -493,6 +514,7 @@ intel_dp_i2c_aux_ch(struct i2c_adapter *adapter, int mode,
int reply_bytes;
int ret;
+ intel_dp_check_edp(intel_dp);
/* Set up the command byte */
if (mode & MODE_I2C_READ)
msg[0] = AUX_I2C_READ << 4;
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