linux-kernel - [PATCH 2/3] coresight: ultrasoc-smb: simplify the code for check to

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Message-ID: <20231012094706.21565-3-hejunhao3@huawei.com>
Date:   Thu, 12 Oct 2023 17:47:05 +0800
From:   Junhao He <hejunhao3@...wei.com>
To:     <suzuki.poulose@....com>, <james.clark@....com>
CC:     <coresight@...ts.linaro.org>,
        <linux-arm-kernel@...ts.infradead.org>,
        <linux-kernel@...r.kernel.org>, <linuxarm@...wei.com>,
        <jonathan.cameron@...wei.com>, <yangyicong@...wei.com>,
        <prime.zeng@...ilicon.com>, <hejunhao3@...wei.com>
Subject: [PATCH 2/3] coresight: ultrasoc-smb: simplify the code for check to_copy valid

We only need to check once when before using the to_copy variable
to simplify the code.

Signed-off-by: Junhao He <hejunhao3@...wei.com>
---
 drivers/hwtracing/coresight/ultrasoc-smb.c | 13 ++++---------
 1 file changed, 4 insertions(+), 9 deletions(-)

diff --git a/drivers/hwtracing/coresight/ultrasoc-smb.c b/drivers/hwtracing/coresight/ultrasoc-smb.c
index b08a619d1116..e78edc3480ce 100644
--- a/drivers/hwtracing/coresight/ultrasoc-smb.c
+++ b/drivers/hwtracing/coresight/ultrasoc-smb.c
@@ -127,20 +127,15 @@ static ssize_t smb_read(struct file *file, char __user *data, size_t len,
 					struct smb_drv_data, miscdev);
 	struct smb_data_buffer *sdb = &drvdata->sdb;
 	struct device *dev = &drvdata->csdev->dev;
-	ssize_t to_copy = 0;
-
-	if (!len)
-		return 0;
-
-	if (!sdb->data_size)
-		return 0;
-
-	to_copy = min(sdb->data_size, len);
+	ssize_t to_copy = min(sdb->data_size, len);
 
 	/* Copy parts of trace data when read pointer wrap around SMB buffer */
 	if (sdb->buf_rdptr + to_copy > sdb->buf_size)
 		to_copy = sdb->buf_size - sdb->buf_rdptr;
 
+	if (!to_copy)
+		return 0;
+
 	if (copy_to_user(data, sdb->buf_base + sdb->buf_rdptr, to_copy)) {
 		dev_dbg(dev, "Failed to copy data to user\n");
 		return -EFAULT;
-- 
2.33.0