[PATCH 2/3] coresight: ultrasoc-smb: simplify the code for check to_copy valid

From: Junhao He
Date: Thu Oct 12 2023 - 05:46:42 EST


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

Signed-off-by: Junhao He <hejunhao3@xxxxxxxxxx>
---
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