Messages in this thread | | | Subject | Re: [PATCH] staging: comedi: usbduxfast: Improve unlocking of a mutex in usbduxfast_ai_insn_read() | From | Ian Abbott <> | Date | Fri, 3 Nov 2017 14:00:18 +0000 |
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On 02/11/17 19:40, SF Markus Elfring wrote: > 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;
Minor niggle: You could also remove that call to mutex_unlock() by replacing the above three lines with:
ret = insn->n;
which will fall through to the 'unlock:' label below.
> + > +unlock: > + mutex_unlock(&devpriv->mut); > + return ret; > } > > static int usbduxfast_upload_firmware(struct comedi_device *dev, >
-- -=( Ian Abbott @ MEV Ltd. E-mail: <abbotti@mev.co.uk> )=- -=( Web: http://www.mev.co.uk/ )=-
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