drm/i915: Clarify error returns from display port aux channel I/O
Use distinct error return values for each kind of aux channel I/O failure.
Signed-off-by: Keith Packard <keithp@keithp.com>
diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index 3f8d7b4..818fe34 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -209,15 +209,19 @@
if ((status & DP_AUX_CH_CTL_DONE) == 0) {
printk(KERN_ERR "dp_aux_ch not done status 0x%08x\n", status);
- return -1;
+ return -EBUSY;
}
/* Check for timeout or receive error.
* Timeouts occur when the sink is not connected
*/
- if (status & (DP_AUX_CH_CTL_TIME_OUT_ERROR | DP_AUX_CH_CTL_RECEIVE_ERROR)) {
- printk(KERN_ERR "dp_aux_ch error status 0x%08x\n", status);
- return -1;
+ if (status & DP_AUX_CH_CTL_RECEIVE_ERROR) {
+ printk(KERN_ERR "dp_aux_ch receive error status 0x%08x\n", status);
+ return -EIO;
+ }
+ if (status & DP_AUX_CH_CTL_TIME_OUT_ERROR) {
+ printk(KERN_ERR "dp_aux_ch timeout status 0x%08x\n", status);
+ return -ETIMEDOUT;
}
/* Unload any bytes sent back from the other side */
@@ -263,7 +267,7 @@
else if ((ack & AUX_NATIVE_REPLY_MASK) == AUX_NATIVE_REPLY_DEFER)
udelay(100);
else
- return -1;
+ return -EIO;
}
return send_bytes;
}
@@ -299,7 +303,9 @@
for (;;) {
ret = intel_dp_aux_ch(intel_output, msg, msg_bytes,
reply, reply_bytes);
- if (ret <= 0)
+ if (ret == 0)
+ return -EPROTO;
+ if (ret < 0)
return ret;
ack = reply[0];
if ((ack & AUX_NATIVE_REPLY_MASK) == AUX_NATIVE_REPLY_ACK) {
@@ -309,7 +315,7 @@
else if ((ack & AUX_NATIVE_REPLY_MASK) == AUX_NATIVE_REPLY_DEFER)
udelay(100);
else
- return -1;
+ return -EIO;
}
}