diff options
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/gpu/drm/drm_dp_helper.c | 42 |
1 files changed, 22 insertions, 20 deletions
diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c index 7dd330a..540c3e4 100644 --- a/drivers/gpu/drm/drm_dp_helper.c +++ b/drivers/gpu/drm/drm_dp_helper.c @@ -178,8 +178,8 @@ static int drm_dp_dpcd_access(struct drm_dp_aux *aux, u8 request, unsigned int offset, void *buffer, size_t size) { struct drm_dp_aux_msg msg; - unsigned int retry; - int err = 0; + unsigned int retry, native_reply; + int err = 0, ret = 0; memset(&msg, 0, sizeof(msg)); msg.address = offset; @@ -196,37 +196,39 @@ static int drm_dp_dpcd_access(struct drm_dp_aux *aux, u8 request, * sufficient, bump to 32 which makes Dell 4k monitors happier. */ for (retry = 0; retry < 32; retry++) { - if (err != 0 && err != -ETIMEDOUT) { + if (ret != 0 && ret != -ETIMEDOUT) { usleep_range(AUX_RETRY_INTERVAL, AUX_RETRY_INTERVAL + 100); } - err = aux->transfer(aux, &msg); - if (err < 0) { - if (err == -EBUSY) - continue; - - goto unlock; - } + ret = aux->transfer(aux, &msg); - switch (msg.reply & DP_AUX_NATIVE_REPLY_MASK) { - case DP_AUX_NATIVE_REPLY_ACK: - if (err < size) - err = -EPROTO; - goto unlock; + if (ret > 0) { + native_reply = msg.reply & DP_AUX_NATIVE_REPLY_MASK; + if (native_reply == DP_AUX_NATIVE_REPLY_ACK) { + if (ret == size) + goto unlock; - case DP_AUX_NATIVE_REPLY_NACK: - err = -EIO; - goto unlock; + ret = -EPROTO; + } else + ret = -EIO; } + + /* + * We want the error we return to be the error we received on + * the first transaction, since we may get a different error the + * next time we retry + */ + if (!err) + err = ret; } DRM_DEBUG_KMS("too many retries, giving up\n"); - err = -EIO; + ret = err; unlock: mutex_unlock(&aux->hw_mutex); - return err; + return ret; } /** |