diff --git a/tools/quest/kgsl_compat.c b/tools/quest/kgsl_compat.c
index 18fd61b0a..f3afa289a 100644
--- a/tools/quest/kgsl_compat.c
+++ b/tools/quest/kgsl_compat.c
@@ -29,7 +29,7 @@ static void report(const char *operation, int error) {
     errno = saved;
 }
 
-#define TRACKED_CONTEXTS 32
+#define TRACKED_CONTEXTS 128
 
 static struct {
     unsigned int context, queued, retired;
@@ -51,7 +51,11 @@ static int tracked_find(unsigned int context, int create) {
         if (free_slot < 0 && tracked[i].context == 0) free_slot = i;
     }
     if (!create) return -1;
-    if (free_slot < 0) free_slot = (int)(context % TRACKED_CONTEXTS);
+    if (free_slot < 0) {
+        free_slot = (int)(context % TRACKED_CONTEXTS);
+        for (int i = 0; i < TRACKED_CONTEXTS; i++)
+            if (tracked[i].queued == tracked[i].retired) { free_slot = i; break; }
+    }
     tracked[free_slot].context = context;
     tracked[free_slot].queued = tracked[free_slot].retired = 0;
     return free_slot;
@@ -81,7 +85,10 @@ static int read_timestamp(quest_ioctl_fn real, int fd, struct kgsl_cmdstream_rea
     unsigned int queued = slot < 0 ? 0 : tracked[slot].queued;
     unsigned int retired = slot < 0 ? 0 : tracked[slot].retired;
     tracked_release();
-    if (slot < 0) { errno = EACCES; return -1; }
+    if (slot < 0 || (query->type != KGSL_TIMESTAMP_RETIRED && query->type != KGSL_TIMESTAMP_QUEUED)) {
+        errno = EACCES;
+        return -1;
+    }
 
     if (query->type == KGSL_TIMESTAMP_RETIRED && (int)(queued - retired) > 0) {
         struct kgsl_device_waittimestamp_ctxtid wait = {
diff --git a/tools/quest/test_kgsl_compat.c b/tools/quest/test_kgsl_compat.c
index 4c9b84e2a..cc453635b 100644
--- a/tools/quest/test_kgsl_compat.c
+++ b/tools/quest/test_kgsl_compat.c
@@ -79,6 +79,7 @@ static void timestamp_scenarios(void) {
     assert(read_ts(5, KGSL_TIMESTAMP_RETIRED, &ts) == -1 && errno == EACCES && ts == 0xdead);
     submit(5, 10);
     assert(read_ts(5, KGSL_TIMESTAMP_QUEUED, &ts) == 0 && ts == 10 && waits == 0);
+    assert(read_ts(5, KGSL_TIMESTAMP_CONSUMED, &ts) == -1 && errno == EACCES && ts == 0xdead);
     wait_error = ETIMEDOUT;
     assert(read_ts(5, KGSL_TIMESTAMP_RETIRED, &ts) == 0 && ts == 0 && waits == 1 && waited_for == 10);
     wait_error = 0;
@@ -96,6 +97,9 @@ static void timestamp_scenarios(void) {
     struct kgsl_drawctxt_destroy gone = {.drawctxt_id = 5};
     assert(quest_kgsl_ioctl(timestamp_mock, 42, IOCTL_KGSL_DRAWCTXT_DESTROY, &gone) == 0);
     assert(read_ts(5, KGSL_TIMESTAMP_QUEUED, &ts) == -1 && errno == EACCES);
+    for (unsigned int c = 100; c < 100 + 130; c++) submit(c, 7);
+    submit(200, 9);
+    assert(read_ts(200, KGSL_TIMESTAMP_QUEUED, &ts) == 0 && ts == 9);
     read_error = EIO;
     submit(6, 3);
     assert(read_ts(6, KGSL_TIMESTAMP_QUEUED, &ts) == -1 && errno == EIO);