linux-kernel - [PATCH 4/7] staging: vt6656: clean error path for firmware management

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Message-ID: <20190520163844.1225-5-quentin.deslandes@itdev.co.uk>
Date:   Mon, 20 May 2019 16:39:03 +0000
From:   Quentin Deslandes <quentin.deslandes@...ev.co.uk>
To:     "devel@...verdev.osuosl.org" <devel@...verdev.osuosl.org>
CC:     Forest Bond <forest@...ttletooquiet.net>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Quentin Deslandes <quentin.deslandes@...ev.co.uk>,
        Mukesh Ojha <mojha@...eaurora.org>,
        Ojaswin Mujoo <ojaswin25111998@...il.com>,
        Nishad Kamdar <nishadkamdar@...il.com>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: [PATCH 4/7] staging: vt6656: clean error path for firmware management

Avoid discarding return value of functions called during firmware
management process. Handle such return value and return 0 on success or
a negative errno value on error.

Signed-off-by: Quentin Deslandes <quentin.deslandes@...ev.co.uk>
---
 drivers/staging/vt6656/firmware.c | 91 ++++++++++++++-----------------
 1 file changed, 40 insertions(+), 51 deletions(-)

diff --git a/drivers/staging/vt6656/firmware.c b/drivers/staging/vt6656/firmware.c
index 38521c338917..60a00af250bf 100644
--- a/drivers/staging/vt6656/firmware.c
+++ b/drivers/staging/vt6656/firmware.c
@@ -30,98 +30,87 @@ int vnt_download_firmware(struct vnt_private *priv)
 {
 	struct device *dev = &priv->usb->dev;
 	const struct firmware *fw;
-	int status;
 	void *buffer = NULL;
-	bool result = false;
 	u16 length;
-	int ii, rc;
+	int ii;
+	int ret = 0;
 
 	dev_dbg(dev, "---->Download firmware\n");
 
-	rc = request_firmware(&fw, FIRMWARE_NAME, dev);
-	if (rc) {
+	ret = request_firmware(&fw, FIRMWARE_NAME, dev);
+	if (ret) {
 		dev_err(dev, "firmware file %s request failed (%d)\n",
-			FIRMWARE_NAME, rc);
-			goto out;
+			FIRMWARE_NAME, ret);
+		goto end;
 	}
 
 	buffer = kmalloc(FIRMWARE_CHUNK_SIZE, GFP_KERNEL);
-	if (!buffer)
+	if (!buffer) {
+		ret = -ENOMEM;
 		goto free_fw;
+	}
 
 	for (ii = 0; ii < fw->size; ii += FIRMWARE_CHUNK_SIZE) {
 		length = min_t(int, fw->size - ii, FIRMWARE_CHUNK_SIZE);
 		memcpy(buffer, fw->data + ii, length);
 
-		status = vnt_control_out(priv,
-					 0,
-					 0x1200 + ii,
-					 0x0000,
-					 length,
-					 buffer);
+		ret = vnt_control_out(priv, 0, 0x1200 + ii, 0x0000, length,
+				      buffer);
+		if (ret)
+			goto free_buffer;
 
 		dev_dbg(dev, "Download firmware...%d %zu\n", ii, fw->size);
-
-		if (status != STATUS_SUCCESS)
-			goto free_fw;
 	}
 
-	result = true;
+free_buffer:
+	kfree(buffer);
 free_fw:
 	release_firmware(fw);
-
-out:
-	kfree(buffer);
-
-	return result;
+end:
+	return ret;
 }
 MODULE_FIRMWARE(FIRMWARE_NAME);
 
 int vnt_firmware_branch_to_sram(struct vnt_private *priv)
 {
-	int status;
-
 	dev_dbg(&priv->usb->dev, "---->Branch to Sram\n");
 
-	status = vnt_control_out(priv,
-				 1,
-				 0x1200,
-				 0x0000,
-				 0,
-				 NULL);
-	return status == STATUS_SUCCESS;
+	return vnt_control_out(priv, 1, 0x1200, 0x0000, 0, NULL);
 }
 
 int vnt_check_firmware_version(struct vnt_private *priv)
 {
-	int status;
-
-	status = vnt_control_in(priv,
-				MESSAGE_TYPE_READ,
-				0,
-				MESSAGE_REQUEST_VERSION,
-				2,
-				(u8 *)&priv->firmware_version);
+	int ret = 0;
+
+	ret = vnt_control_in(priv, MESSAGE_TYPE_READ, 0,
+			     MESSAGE_REQUEST_VERSION, 2,
+			     (u8 *)&priv->firmware_version);
+	if (ret) {
+		dev_dbg(&priv->usb->dev,
+			"Could not get firmware version: %d.\n", ret);
+		goto end;
+	}
 
 	dev_dbg(&priv->usb->dev, "Firmware Version [%04x]\n",
 		priv->firmware_version);
 
-	if (status != STATUS_SUCCESS) {
-		dev_dbg(&priv->usb->dev, "Firmware Invalid.\n");
-		return false;
-	}
 	if (priv->firmware_version == 0xFFFF) {
 		dev_dbg(&priv->usb->dev, "In Loader.\n");
-		return false;
+		ret = -EINVAL;
+		goto end;
 	}
 
-	dev_dbg(&priv->usb->dev, "Firmware Version [%04x]\n",
-		priv->firmware_version);
-
 	if (priv->firmware_version < FIRMWARE_VERSION) {
 		/* branch to loader for download new firmware */
-		vnt_firmware_branch_to_sram(priv);
-		return false;
+		ret = vnt_firmware_branch_to_sram(priv);
+		if (ret) {
+			dev_dbg(&priv->usb->dev,
+				"Could not branch to SRAM: %d.\n", ret);
+		} else {
+			ret = -EINVAL;
+		}
 	}
-	return true;
+
+end:
+	return ret;
 }
-- 
2.17.1