capture-ivc: fix multi-cam race condition

add semaphore to avoid multi-cam race condition

Bug 4425972

Change-Id: I6e01ccb0596efed32ed53618ccf80c1e751b4f29
Signed-off-by: Jerry Chang <jerchang@nvidia.com>
Reviewed-on: https://git-master.nvidia.com/r/c/linux-nv-oot/+/3315501
Reviewed-by: svcacv <svcacv@nvidia.com>
Reviewed-by: Anubhav Rai <arai@nvidia.com>
Reviewed-by: Shan Neng Chen <snchen@nvidia.com>
Reviewed-by: Narendra Kondapalli <nkondapalli@nvidia.com>
GVS: buildbot_gerritrpt <buildbot_gerritrpt@nvidia.com>
Tested-by: Shan Neng Chen <snchen@nvidia.com>

drivers/platform/tegra/rtcpu/capture-ivc-priv.h

@@ -1,6 +1,16 @@
-/* SPDX-License-Identifier: GPL-2.0-only */
+/* SPDX-License-Identifier: LicenseRef-NvidiaProprietary
-/*
+ *
- * Copyright (c) 2022-2023, NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+ * SPDX-FileCopyrightText: Copyright (c) 2017-2025 NVIDIA CORPORATION.
+ *                         All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
  */
 
 #ifndef __CAPTURE_IVC_PRIV_H__
@@ -26,6 +36,7 @@ struct tegra_capture_ivc_cb_ctx {
 	tegra_capture_ivc_cb_func cb_func;
 	/** Private context of a VI/ISP capture context */
 	const void *priv_context;
+	struct semaphore sem_ch;
 };
 
 /**

drivers/platform/tegra/rtcpu/capture-ivc.c

@@ -1,6 +1,20 @@
-// SPDX-License-Identifier: GPL-2.0
+// SPDX-License-Identifier: LicenseRef-NvidiaProprietary
-// Copyright (c) 2022-2024, NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+/*
-
+ * SPDX-FileCopyrightText: Copyright (c) 2017-2025 NVIDIA CORPORATION.
+ *                         All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
 #include <nvidia/conftest.h>
 
 #include <linux/tegra-capture-ivc.h>
@@ -17,12 +31,17 @@
 #include <linux/kthread.h>
 #include <linux/sched.h>
 #include <linux/version.h>
+#include <linux/semaphore.h>
 #include <asm/barrier.h>
 
 #include <trace/events/tegra_capture.h>
 
 #include "capture-ivc-priv.h"
 
+/* Timeout for acquiring channel-id */
+#define TIMEOUT_ACQUIRE_CHANNEL_ID 120
+
+
 static int tegra_capture_ivc_tx_(struct tegra_capture_ivc *civc,
 				const void *req, size_t len)
 {
@@ -184,6 +203,11 @@ int tegra_capture_ivc_notify_chan_id(uint32_t chan_id, uint32_t trans_id)
 
 	civc = __scivc_control;
 
+	if (down_timeout(&civc->cb_ctx[chan_id].sem_ch,
+				TIMEOUT_ACQUIRE_CHANNEL_ID)) {
+		return -EBUSY;
+	}
+
 	mutex_lock(&civc->cb_ctx_lock);
 
 	if (WARN(civc->cb_ctx[trans_id].cb_func == NULL,
@@ -288,6 +312,7 @@ int tegra_capture_ivc_unregister_control_cb(uint32_t id)
 	civc->cb_ctx[id].priv_context = NULL;
 
 	mutex_unlock(&civc->cb_ctx_lock);
+	up(&civc->cb_ctx[id].sem_ch);
 
 	/*
 	 * If it's trans_id, client encountered an error before or during
@@ -454,6 +479,9 @@ static int tegra_capture_ivc_probe(struct tegra_ivc_channel *chan)
 	mutex_init(&civc->cb_ctx_lock);
 	mutex_init(&civc->ivc_wr_lock);
 
+	for (i = 0; i < TOTAL_CHANNELS; i++)
+		sema_init(&civc->cb_ctx[i].sem_ch, 1);
+
 	/* Initialize kworker */
 	kthread_init_work(&civc->work, tegra_capture_ivc_worker);