3 files changed, 46 insertions, 1 deletions

diff --git a/drivers/gpu/host1x/dev.c b/drivers/gpu/host1x/dev.c
index d0ebb70e2fdd..fbb6447b8659 100644
--- a/drivers/gpu/host1x/dev.c
+++ b/drivers/gpu/host1x/dev.c
@@ -77,6 +77,7 @@ static const struct host1x_info host1x01_info = {
 	.has_hypervisor = false,
 	.num_sid_entries = 0,
 	.sid_table = NULL,
+	.reserve_vblank_syncpts = true,
 };
 
 static const struct host1x_info host1x02_info = {
@@ -91,6 +92,7 @@ static const struct host1x_info host1x02_info = {
 	.has_hypervisor = false,
 	.num_sid_entries = 0,
 	.sid_table = NULL,
+	.reserve_vblank_syncpts = true,
 };
 
 static const struct host1x_info host1x04_info = {
@@ -105,6 +107,7 @@ static const struct host1x_info host1x04_info = {
 	.has_hypervisor = false,
 	.num_sid_entries = 0,
 	.sid_table = NULL,
+	.reserve_vblank_syncpts = false,
 };
 
 static const struct host1x_info host1x05_info = {
@@ -119,6 +122,7 @@ static const struct host1x_info host1x05_info = {
 	.has_hypervisor = false,
 	.num_sid_entries = 0,
 	.sid_table = NULL,
+	.reserve_vblank_syncpts = false,
 };
 
 static const struct host1x_sid_entry tegra186_sid_table[] = {
@@ -142,6 +146,7 @@ static const struct host1x_info host1x06_info = {
 	.has_hypervisor = true,
 	.num_sid_entries = ARRAY_SIZE(tegra186_sid_table),
 	.sid_table = tegra186_sid_table,
+	.reserve_vblank_syncpts = false,
 };
 
 static const struct host1x_sid_entry tegra194_sid_table[] = {
@@ -165,6 +170,7 @@ static const struct host1x_info host1x07_info = {
 	.has_hypervisor = true,
 	.num_sid_entries = ARRAY_SIZE(tegra194_sid_table),
 	.sid_table = tegra194_sid_table,
+	.reserve_vblank_syncpts = false,
 };
 
 static const struct of_device_id host1x_of_match[] = {
diff --git a/drivers/gpu/host1x/dev.h b/drivers/gpu/host1x/dev.h
index 63010ae37a97..fa6d4bc46e98 100644
--- a/drivers/gpu/host1x/dev.h
+++ b/drivers/gpu/host1x/dev.h
@@ -101,6 +101,12 @@ struct host1x_info {
 	bool has_hypervisor; /* has hypervisor registers */
 	unsigned int num_sid_entries;
 	const struct host1x_sid_entry *sid_table;
+	/*
+	 * On T20-T148, the boot chain may setup DC to increment syncpoints
+	 * 26/27 on VBLANK. As such we cannot use these syncpoints until
+	 * the display driver disables VBLANK increments.
+	 */
+	bool reserve_vblank_syncpts;
 };
 
 struct host1x {
diff --git a/drivers/gpu/host1x/syncpt.c b/drivers/gpu/host1x/syncpt.c
index 877c5ab40cbd..e648ebbb2027 100644
--- a/drivers/gpu/host1x/syncpt.c
+++ b/drivers/gpu/host1x/syncpt.c
@@ -67,7 +67,7 @@ struct host1x_syncpt *host1x_syncpt_alloc(struct host1x *host,
 
 	mutex_lock(&host->syncpt_mutex);
 
-	for (i = 0; i < host->info->nb_pts && sp->name; i++, sp++)
+	for (i = 0; i < host->info->nb_pts && kref_read(&sp->ref); i++, sp++)
 		;
 
 	if (i >= host->info->nb_pts)
@@ -374,6 +374,11 @@ int host1x_syncpt_init(struct host1x *host)
 	if (!host->nop_sp)
 		return -ENOMEM;
 
+	if (host->info->reserve_vblank_syncpts) {
+		kref_init(&host->syncpt[26].ref);
+		kref_init(&host->syncpt[27].ref);
+	}
+
 	return 0;
 }
 
@@ -559,3 +564,31 @@ u32 host1x_syncpt_base_id(struct host1x_syncpt_base *base)
 	return base->id;
 }
 EXPORT_SYMBOL(host1x_syncpt_base_id);
+
+static void do_nothing(struct kref *ref)
+{
+}
+
+/**
+ * host1x_syncpt_release_vblank_reservation() - Make VBLANK syncpoint
+ *   available for allocation
+ *
+ * @client: host1x bus client
+ * @syncpt_id: syncpoint ID to make available
+ *
+ * Makes VBLANK<i> syncpoint available for allocatation if it was
+ * reserved at initialization time. This should be called by the display
+ * driver after it has ensured that any VBLANK increment programming configured
+ * by the boot chain has been disabled.
+ */
+void host1x_syncpt_release_vblank_reservation(struct host1x_client *client,
+					      u32 syncpt_id)
+{
+	struct host1x *host = dev_get_drvdata(client->host->parent);
+
+	if (!host->info->reserve_vblank_syncpts)
+		return;
+
+	kref_put(&host->syncpt[syncpt_id].ref, do_nothing);
+}
+EXPORT_SYMBOL(host1x_syncpt_release_vblank_reservation);