Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Received-SPF: Pass (protection.outlook.com: domain of nvidia.com designates
 216.228.117.160 as permitted sender) receiver=protection.outlook.com;
 client-ip=216.228.117.160; helo=mail.nvidia.com; pr=C
From:   Akhil R <akhilrajeev@nvidia.com>
To:     <christian.koenig@amd.com>, <digetx@gmail.com>,
        <jonathanh@nvidia.com>, <ldewangan@nvidia.com>,
        <linux-i2c@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
        <linux-tegra@vger.kernel.org>, <sumit.semwal@linaro.org>,
        <thierry.reding@gmail.com>, <wsa@kernel.org>
CC:     <akhilrajeev@nvidia.com>
Subject: [PATCH] i2c: tegra: Fix the check during DMA channel release
Date:   Mon, 17 Jul 2023 20:42:40 +0530
Message-ID: <20230717151240.68899-1-akhilrajeev@nvidia.com>
MIME-Version: 1.0
Content-Type: text/plain
X-MS-Exchange-CrossTenant-OriginalArrivalTime: 17 Jul 2023 15:13:29.9405
 (UTC)
X-MS-Exchange-CrossTenant-Network-Message-Id: 1dc5f98e-c7ff-4224-4684-08db86d860ee
X-MS-Exchange-CrossTenant-Id: 43083d15-7273-40c1-b7db-39efd9ccc17a
X-MS-Exchange-CrossTenant-OriginalAttributedTenantConnectingIp: TenantId=43083d15-7273-40c1-b7db-39efd9ccc17a;Ip=[216.228.117.160];Helo=[mail.nvidia.com]
X-MS-Exchange-CrossTenant-AuthSource: CO1NAM11FT096.eop-nam11.prod.protection.outlook.com
X-MS-Exchange-CrossTenant-AuthAs: Anonymous
X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem
X-MS-Exchange-Transport-CrossTenantHeadersStamped: SN7PR12MB8771
X-Spam-Status: No, score=-1.1 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH,
        DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,FORGED_SPF_HELO,
        RCVD_IN_DNSWL_BLOCKED,RCVD_IN_MSPIKE_H2,SPF_HELO_PASS,SPF_NONE,
        T_SCC_BODY_TEXT_LINE autolearn=no autolearn_force=no version=3.4.6
X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on
        lindbergh.monkeyblade.net
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

Check for error and NULL before attempting to release DMA channel.

This, otherwise, was causing panic and crash in kernel when the
dma_chan has an invalid value. The condition occurs during init_dma()
when the dma_request_chan() function returns an error.

Fixes: fcc8a89a1c83 ("i2c: tegra: Share same DMA channel for RX and TX")
Signed-off-by: Akhil R <akhilrajeev@nvidia.com>
---
 drivers/i2c/busses/i2c-tegra.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/i2c/busses/i2c-tegra.c b/drivers/i2c/busses/i2c-tegra.c
index bcbbf23aa530..636bf340e707 100644
--- a/drivers/i2c/busses/i2c-tegra.c
+++ b/drivers/i2c/busses/i2c-tegra.c
@@ -427,7 +427,7 @@ static void tegra_i2c_release_dma(struct tegra_i2c_dev *i2c_dev)
 		i2c_dev->dma_buf = NULL;
 	}
 
-	if (i2c_dev->dma_chan) {
+	if (!IS_ERR_OR_NULL(i2c_dev->dma_chan)) {
 		dma_release_channel(i2c_dev->dma_chan);
 		i2c_dev->dma_chan = NULL;
 	}
-- 
2.17.1