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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.c58
1 files changed, 28 insertions, 30 deletions
diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index 9caccd03dcc..51d142939a2 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -239,7 +239,6 @@ intel_dp_aux_ch(struct intel_dp *intel_dp,
uint32_t ch_data = ch_ctl + 4;
int i;
int recv_bytes;
- uint32_t ctl;
uint32_t status;
uint32_t aux_clock_divider;
int try, precharge;
@@ -263,41 +262,43 @@ intel_dp_aux_ch(struct intel_dp *intel_dp,
else
precharge = 5;
+ if (I915_READ(ch_ctl) & DP_AUX_CH_CTL_SEND_BUSY) {
+ DRM_ERROR("dp_aux_ch not started status 0x%08x\n",
+ I915_READ(ch_ctl));
+ return -EBUSY;
+ }
+
/* Must try at least 3 times according to DP spec */
for (try = 0; try < 5; try++) {
/* Load the send data into the aux channel data registers */
- for (i = 0; i < send_bytes; i += 4) {
- uint32_t d = pack_aux(send + i, send_bytes - i);
-
- I915_WRITE(ch_data + i, d);
- }
-
- ctl = (DP_AUX_CH_CTL_SEND_BUSY |
- DP_AUX_CH_CTL_TIME_OUT_400us |
- (send_bytes << DP_AUX_CH_CTL_MESSAGE_SIZE_SHIFT) |
- (precharge << DP_AUX_CH_CTL_PRECHARGE_2US_SHIFT) |
- (aux_clock_divider << DP_AUX_CH_CTL_BIT_CLOCK_2X_SHIFT) |
- DP_AUX_CH_CTL_DONE |
- DP_AUX_CH_CTL_TIME_OUT_ERROR |
- DP_AUX_CH_CTL_RECEIVE_ERROR);
+ for (i = 0; i < send_bytes; i += 4)
+ I915_WRITE(ch_data + i,
+ pack_aux(send + i, send_bytes - i));
/* Send the command and wait for it to complete */
- I915_WRITE(ch_ctl, ctl);
- (void) I915_READ(ch_ctl);
+ I915_WRITE(ch_ctl,
+ DP_AUX_CH_CTL_SEND_BUSY |
+ DP_AUX_CH_CTL_TIME_OUT_400us |
+ (send_bytes << DP_AUX_CH_CTL_MESSAGE_SIZE_SHIFT) |
+ (precharge << DP_AUX_CH_CTL_PRECHARGE_2US_SHIFT) |
+ (aux_clock_divider << DP_AUX_CH_CTL_BIT_CLOCK_2X_SHIFT) |
+ DP_AUX_CH_CTL_DONE |
+ DP_AUX_CH_CTL_TIME_OUT_ERROR |
+ DP_AUX_CH_CTL_RECEIVE_ERROR);
for (;;) {
- udelay(100);
status = I915_READ(ch_ctl);
if ((status & DP_AUX_CH_CTL_SEND_BUSY) == 0)
break;
+ udelay(100);
}
/* Clear done status and any errors */
- I915_WRITE(ch_ctl, (status |
- DP_AUX_CH_CTL_DONE |
- DP_AUX_CH_CTL_TIME_OUT_ERROR |
- DP_AUX_CH_CTL_RECEIVE_ERROR));
- (void) I915_READ(ch_ctl);
- if ((status & DP_AUX_CH_CTL_TIME_OUT_ERROR) == 0)
+ I915_WRITE(ch_ctl,
+ status |
+ DP_AUX_CH_CTL_DONE |
+ DP_AUX_CH_CTL_TIME_OUT_ERROR |
+ DP_AUX_CH_CTL_RECEIVE_ERROR);
+ if (status & DP_AUX_CH_CTL_DONE)
break;
}
@@ -324,15 +325,12 @@ intel_dp_aux_ch(struct intel_dp *intel_dp,
/* Unload any bytes sent back from the other side */
recv_bytes = ((status & DP_AUX_CH_CTL_MESSAGE_SIZE_MASK) >>
DP_AUX_CH_CTL_MESSAGE_SIZE_SHIFT);
-
if (recv_bytes > recv_size)
recv_bytes = recv_size;
- for (i = 0; i < recv_bytes; i += 4) {
- uint32_t d = I915_READ(ch_data + i);
-
- unpack_aux(d, recv + i, recv_bytes - i);
- }
+ for (i = 0; i < recv_bytes; i += 4)
+ unpack_aux(I915_READ(ch_data + i),
+ recv + i, recv_bytes - i);
return recv_bytes;
}