diff options
Diffstat (limited to 'drivers/gpu/drm/i915/intel_dp.c')
| -rw-r--r-- | drivers/gpu/drm/i915/intel_dp.c | 19 |
1 files changed, 13 insertions, 6 deletions
diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c index 2f517b85b3f..57552eb386b 100644 --- a/drivers/gpu/drm/i915/intel_dp.c +++ b/drivers/gpu/drm/i915/intel_dp.c @@ -537,6 +537,7 @@ intel_dp_aux_native_write(struct intel_dp *intel_dp, uint8_t msg[20]; int msg_bytes; uint8_t ack; + int retry; if (WARN_ON(send_bytes > 16)) return -E2BIG; @@ -548,19 +549,21 @@ intel_dp_aux_native_write(struct intel_dp *intel_dp, msg[3] = send_bytes - 1; memcpy(&msg[4], send, send_bytes); msg_bytes = send_bytes + 4; - for (;;) { + for (retry = 0; retry < 7; retry++) { ret = intel_dp_aux_ch(intel_dp, msg, msg_bytes, &ack, 1); if (ret < 0) return ret; ack >>= 4; if ((ack & DP_AUX_NATIVE_REPLY_MASK) == DP_AUX_NATIVE_REPLY_ACK) - break; + return send_bytes; else if ((ack & DP_AUX_NATIVE_REPLY_MASK) == DP_AUX_NATIVE_REPLY_DEFER) - udelay(100); + usleep_range(400, 500); else return -EIO; } - return send_bytes; + + DRM_ERROR("too many retries, giving up\n"); + return -EIO; } /* Write a single byte to the aux channel in native mode */ @@ -582,6 +585,7 @@ intel_dp_aux_native_read(struct intel_dp *intel_dp, int reply_bytes; uint8_t ack; int ret; + int retry; if (WARN_ON(recv_bytes > 19)) return -E2BIG; @@ -595,7 +599,7 @@ intel_dp_aux_native_read(struct intel_dp *intel_dp, msg_bytes = 4; reply_bytes = recv_bytes + 1; - for (;;) { + for (retry = 0; retry < 7; retry++) { ret = intel_dp_aux_ch(intel_dp, msg, msg_bytes, reply, reply_bytes); if (ret == 0) @@ -608,10 +612,13 @@ intel_dp_aux_native_read(struct intel_dp *intel_dp, return ret - 1; } else if ((ack & DP_AUX_NATIVE_REPLY_MASK) == DP_AUX_NATIVE_REPLY_DEFER) - udelay(100); + usleep_range(400, 500); else return -EIO; } + + DRM_ERROR("too many retries, giving up\n"); + return -EIO; } static int |