From: SF Markus Elfring <elfring@users.sourceforge.net>
To: devel@driverdev.osuosl.org,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
H Hartley Sweeten <hsweeten@visionengravers.com>,
Ian Abbott <abbotti@mev.co.uk>
Cc: LKML <linux-kernel@vger.kernel.org>, kernel-janitors@vger.kernel.org
Subject: [PATCH] staging: comedi: usbduxfast: Improve unlocking of a mutex in usbduxfast_ai_insn_read()
Date: Thu, 2 Nov 2017 20:40:12 +0100 [thread overview]
Message-ID: <b0acc12a-e48c-d51a-f7e3-606e66e6fe7b@users.sourceforge.net> (raw)
From: Markus Elfring <elfring@users.sourceforge.net>
Date: Thu, 2 Nov 2017 20:30:31 +0100
* Add a jump target so that a call of the function "mutex_unlock" is stored
only twice in this function implementation.
* Replace five calls by goto statements.
This issue was detected by using the Coccinelle software.
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
---
drivers/staging/comedi/drivers/usbduxfast.c | 24 ++++++++++++------------
1 file changed, 12 insertions(+), 12 deletions(-)
diff --git a/drivers/staging/comedi/drivers/usbduxfast.c b/drivers/staging/comedi/drivers/usbduxfast.c
index 608403c7586b..e5884faf7275 100644
--- a/drivers/staging/comedi/drivers/usbduxfast.c
+++ b/drivers/staging/comedi/drivers/usbduxfast.c
@@ -777,8 +777,8 @@ static int usbduxfast_ai_insn_read(struct comedi_device *dev,
if (devpriv->ai_cmd_running) {
dev_err(dev->class_dev,
"ai_insn_read not possible, async cmd is running\n");
- mutex_unlock(&devpriv->mut);
- return -EBUSY;
+ ret = -EBUSY;
+ goto unlock;
}
/* set command for the first channel */
@@ -798,10 +798,8 @@ static int usbduxfast_ai_insn_read(struct comedi_device *dev,
usbduxfast_cmd_data(dev, 6, 0x01, 0x00, rngmask, 0x00);
ret = usbduxfast_send_cmd(dev, SENDADCOMMANDS);
- if (ret < 0) {
- mutex_unlock(&devpriv->mut);
- return ret;
- }
+ if (ret < 0)
+ goto unlock;
for (i = 0; i < PACKETS_TO_IGNORE; i++) {
ret = usb_bulk_msg(usb, usb_rcvbulkpipe(usb, BULKINEP),
@@ -809,8 +807,7 @@ static int usbduxfast_ai_insn_read(struct comedi_device *dev,
&actual_length, 10000);
if (ret < 0) {
dev_err(dev->class_dev, "insn timeout, no data\n");
- mutex_unlock(&devpriv->mut);
- return ret;
+ goto unlock;
}
}
@@ -820,14 +817,13 @@ static int usbduxfast_ai_insn_read(struct comedi_device *dev,
&actual_length, 10000);
if (ret < 0) {
dev_err(dev->class_dev, "insn data error: %d\n", ret);
- mutex_unlock(&devpriv->mut);
- return ret;
+ goto unlock;
}
n = actual_length / sizeof(u16);
if ((n % 16) != 0) {
dev_err(dev->class_dev, "insn data packet corrupted\n");
- mutex_unlock(&devpriv->mut);
- return -EINVAL;
+ ret = -EINVAL;
+ goto unlock;
}
for (j = chan; (j < n) && (i < insn->n); j = j + 16) {
data[i] = ((u16 *)(devpriv->inbuf))[j];
@@ -838,6 +834,10 @@ static int usbduxfast_ai_insn_read(struct comedi_device *dev,
mutex_unlock(&devpriv->mut);
return insn->n;
+
+unlock:
+ mutex_unlock(&devpriv->mut);
+ return ret;
}
static int usbduxfast_upload_firmware(struct comedi_device *dev,
--
2.15.0
next reply other threads:[~2017-11-02 19:40 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-11-02 19:40 SF Markus Elfring [this message]
2017-11-03 14:00 ` [PATCH] staging: comedi: usbduxfast: Improve unlocking of a mutex in usbduxfast_ai_insn_read() Ian Abbott
2017-11-03 14:14 ` Greg Kroah-Hartman
2017-11-03 17:07 ` SF Markus Elfring
2017-11-03 16:39 ` [PATCH] " SF Markus Elfring
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