6 files changed, 92 insertions, 44 deletions

diff --git a/drivers/dma-buf/dma-fence.c b/drivers/dma-buf/dma-fence.c
index 57da14c15987..56e0a0e1b600 100644
--- a/drivers/dma-buf/dma-fence.c
+++ b/drivers/dma-buf/dma-fence.c
@@ -75,11 +75,6 @@ int dma_fence_signal_locked(struct dma_fence *fence)
         if (WARN_ON(!fence))
                 return -EINVAL;
 
-        if (!ktime_to_ns(fence->timestamp)) {
-                fence->timestamp = ktime_get();
-                smp_mb__before_atomic();
-        }
-
         if (test_and_set_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &fence->flags)) {
                 ret = -EINVAL;
 
@@ -87,8 +82,11 @@ int dma_fence_signal_locked(struct dma_fence *fence)
                  * we might have raced with the unlocked dma_fence_signal,
                  * still run through all callbacks
                  */
-        } else
+        } else {
+                fence->timestamp = ktime_get();
+                set_bit(DMA_FENCE_FLAG_TIMESTAMP_BIT, &fence->flags);
                 trace_dma_fence_signaled(fence);
+        }
 
         list_for_each_entry_safe(cur, tmp, &fence->cb_list, node) {
                 list_del_init(&cur->node);
@@ -115,14 +113,11 @@ int dma_fence_signal(struct dma_fence *fence)
         if (!fence)
                 return -EINVAL;
 
-        if (!ktime_to_ns(fence->timestamp)) {
-                fence->timestamp = ktime_get();
-                smp_mb__before_atomic();
-        }
-
         if (test_and_set_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &fence->flags))
                 return -EINVAL;
 
+        fence->timestamp = ktime_get();
+        set_bit(DMA_FENCE_FLAG_TIMESTAMP_BIT, &fence->flags);
         trace_dma_fence_signaled(fence);
 
         if (test_bit(DMA_FENCE_FLAG_ENABLE_SIGNAL_BIT, &fence->flags)) {
diff --git a/drivers/dma-buf/sync_debug.c b/drivers/dma-buf/sync_debug.c
index 82a6e7f6d37f..59a3b2f8ee91 100644
--- a/drivers/dma-buf/sync_debug.c
+++ b/drivers/dma-buf/sync_debug.c
@@ -84,7 +84,7 @@ static void sync_print_fence(struct seq_file *s,
                    show ? "_" : "",
                    sync_status_str(status));
 
-        if (status) {
+        if (test_bit(DMA_FENCE_FLAG_TIMESTAMP_BIT, &fence->flags)) {
                 struct timespec64 ts64 =
                         ktime_to_timespec64(fence->timestamp);
 
diff --git a/drivers/dma-buf/sync_file.c b/drivers/dma-buf/sync_file.c
index 545e2c5c4815..d7e219d2669d 100644
--- a/drivers/dma-buf/sync_file.c
+++ b/drivers/dma-buf/sync_file.c
@@ -391,7 +391,13 @@ static void sync_fill_fence_info(struct dma_fence *fence,
                 sizeof(info->driver_name));
 
         info->status = dma_fence_get_status(fence);
-        info->timestamp_ns = ktime_to_ns(fence->timestamp);
+        while (test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &fence->flags) &&
+               !test_bit(DMA_FENCE_FLAG_TIMESTAMP_BIT, &fence->flags))
+                cpu_relax();
+        info->timestamp_ns =
+                test_bit(DMA_FENCE_FLAG_TIMESTAMP_BIT, &fence->flags) ?
+                ktime_to_ns(fence->timestamp) :
+                ktime_set(0, 0);
 }
 
 static long sync_file_ioctl_fence_info(struct sync_file *sync_file,
diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c
index bfd237c15e76..ae5f06895562 100644
--- a/drivers/gpu/drm/drm_dp_mst_topology.c
+++ b/drivers/gpu/drm/drm_dp_mst_topology.c
@@ -330,6 +330,13 @@ static bool drm_dp_sideband_msg_build(struct drm_dp_sideband_msg_rx *msg,
                         return false;
                 }
 
+                /*
+                 * ignore out-of-order messages or messages that are part of a
+                 * failed transaction
+                 */
+                if (!recv_hdr.somt && !msg->have_somt)
+                        return false;
+
                 /* get length contained in this portion */
                 msg->curchunk_len = recv_hdr.msg_len;
                 msg->curchunk_hdrlen = hdrlen;
@@ -2164,7 +2171,7 @@ out_unlock:
 }
 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_resume);
 
-static void drm_dp_get_one_sb_msg(struct drm_dp_mst_topology_mgr *mgr, bool up)
+static bool drm_dp_get_one_sb_msg(struct drm_dp_mst_topology_mgr *mgr, bool up)
 {
         int len;
         u8 replyblock[32];
@@ -2179,12 +2186,12 @@ static void drm_dp_get_one_sb_msg(struct drm_dp_mst_topology_mgr *mgr, bool up)
                                replyblock, len);
         if (ret != len) {
                 DRM_DEBUG_KMS("failed to read DPCD down rep %d %d\n", len, ret);
-                return;
+                return false;
         }
         ret = drm_dp_sideband_msg_build(msg, replyblock, len, true);
         if (!ret) {
                 DRM_DEBUG_KMS("sideband msg build failed %d\n", replyblock[0]);
-                return;
+                return false;
         }
         replylen = msg->curchunk_len + msg->curchunk_hdrlen;
 
@@ -2196,21 +2203,32 @@ static void drm_dp_get_one_sb_msg(struct drm_dp_mst_topology_mgr *mgr, bool up)
                 ret = drm_dp_dpcd_read(mgr->aux, basereg + curreply,
                                     replyblock, len);
                 if (ret != len) {
-                        DRM_DEBUG_KMS("failed to read a chunk\n");
+                        DRM_DEBUG_KMS("failed to read a chunk (len %d, ret %d)\n",
+                                      len, ret);
+                        return false;
                 }
+
                 ret = drm_dp_sideband_msg_build(msg, replyblock, len, false);
-                if (ret == false)
+                if (!ret) {
                         DRM_DEBUG_KMS("failed to build sideband msg\n");
+                        return false;
+                }
+
                 curreply += len;
                 replylen -= len;
         }
+        return true;
 }
 
 static int drm_dp_mst_handle_down_rep(struct drm_dp_mst_topology_mgr *mgr)
 {
         int ret = 0;
 
-        drm_dp_get_one_sb_msg(mgr, false);
+        if (!drm_dp_get_one_sb_msg(mgr, false)) {
+                memset(&mgr->down_rep_recv, 0,
+                       sizeof(struct drm_dp_sideband_msg_rx));
+                return 0;
+        }
 
         if (mgr->down_rep_recv.have_eomt) {
                 struct drm_dp_sideband_msg_tx *txmsg;
@@ -2266,7 +2284,12 @@ static int drm_dp_mst_handle_down_rep(struct drm_dp_mst_topology_mgr *mgr)
 static int drm_dp_mst_handle_up_req(struct drm_dp_mst_topology_mgr *mgr)
 {
         int ret = 0;
-        drm_dp_get_one_sb_msg(mgr, true);
+
+        if (!drm_dp_get_one_sb_msg(mgr, true)) {
+                memset(&mgr->up_req_recv, 0,
+                       sizeof(struct drm_dp_sideband_msg_rx));
+                return 0;
+        }
 
         if (mgr->up_req_recv.have_eomt) {
                 struct drm_dp_sideband_msg_req_body msg;
@@ -2318,7 +2341,9 @@ static int drm_dp_mst_handle_up_req(struct drm_dp_mst_topology_mgr *mgr)