diff options
author | David S. Miller <davem@davemloft.net> | 2013-08-04 04:36:46 (GMT) |
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committer | David S. Miller <davem@davemloft.net> | 2013-08-04 04:36:46 (GMT) |
commit | 0e76a3a587fc7abda2badf249053b427baad255e (patch) | |
tree | 646a1da67dc25654552028225ca4b7a0a8043cc9 /drivers/staging/comedi/comedi_fops.c | |
parent | fba3679d34511c42bf452e89dda457a1219eb43a (diff) | |
parent | 72a67a94bcba71a5fddd6b3596a20604d2b5dcd6 (diff) | |
download | linux-fsl-qoriq-0e76a3a587fc7abda2badf249053b427baad255e.tar.xz |
Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Merge net into net-next to setup some infrastructure Eric
Dumazet needs for usbnet changes.
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/staging/comedi/comedi_fops.c')
-rw-r--r-- | drivers/staging/comedi/comedi_fops.c | 32 |
1 files changed, 21 insertions, 11 deletions
diff --git a/drivers/staging/comedi/comedi_fops.c b/drivers/staging/comedi/comedi_fops.c index 8647518..f4a197b 100644 --- a/drivers/staging/comedi/comedi_fops.c +++ b/drivers/staging/comedi/comedi_fops.c @@ -1413,22 +1413,19 @@ static int do_cmd_ioctl(struct comedi_device *dev, DPRINTK("subdevice busy\n"); return -EBUSY; } - s->busy = file; /* make sure channel/gain list isn't too long */ if (cmd.chanlist_len > s->len_chanlist) { DPRINTK("channel/gain list too long %u > %d\n", cmd.chanlist_len, s->len_chanlist); - ret = -EINVAL; - goto cleanup; + return -EINVAL; } /* make sure channel/gain list isn't too short */ if (cmd.chanlist_len < 1) { DPRINTK("channel/gain list too short %u < 1\n", cmd.chanlist_len); - ret = -EINVAL; - goto cleanup; + return -EINVAL; } async->cmd = cmd; @@ -1438,8 +1435,7 @@ static int do_cmd_ioctl(struct comedi_device *dev, kmalloc(async->cmd.chanlist_len * sizeof(int), GFP_KERNEL); if (!async->cmd.chanlist) { DPRINTK("allocation failed\n"); - ret = -ENOMEM; - goto cleanup; + return -ENOMEM; } if (copy_from_user(async->cmd.chanlist, user_chanlist, @@ -1491,6 +1487,9 @@ static int do_cmd_ioctl(struct comedi_device *dev, comedi_set_subdevice_runflags(s, ~0, SRF_USER | SRF_RUNNING); + /* set s->busy _after_ setting SRF_RUNNING flag to avoid race with + * comedi_read() or comedi_write() */ + s->busy = file; ret = s->do_cmd(dev, s); if (ret == 0) return 0; @@ -1705,6 +1704,7 @@ static int do_cancel_ioctl(struct comedi_device *dev, unsigned int arg, void *file) { struct comedi_subdevice *s; + int ret; if (arg >= dev->n_subdevices) return -EINVAL; @@ -1721,7 +1721,11 @@ static int do_cancel_ioctl(struct comedi_device *dev, unsigned int arg, if (s->busy != file) return -EBUSY; - return do_cancel(dev, s); + ret = do_cancel(dev, s); + if (comedi_get_subdevice_runflags(s) & SRF_USER) + wake_up_interruptible(&s->async->wait_head); + + return ret; } /* @@ -2053,11 +2057,13 @@ static ssize_t comedi_write(struct file *file, const char __user *buf, if (!comedi_is_subdevice_running(s)) { if (count == 0) { + mutex_lock(&dev->mutex); if (comedi_is_subdevice_in_error(s)) retval = -EPIPE; else retval = 0; do_become_nonbusy(dev, s); + mutex_unlock(&dev->mutex); } break; } @@ -2156,11 +2162,13 @@ static ssize_t comedi_read(struct file *file, char __user *buf, size_t nbytes, if (n == 0) { if (!comedi_is_subdevice_running(s)) { + mutex_lock(&dev->mutex); do_become_nonbusy(dev, s); if (comedi_is_subdevice_in_error(s)) retval = -EPIPE; else retval = 0; + mutex_unlock(&dev->mutex); break; } if (file->f_flags & O_NONBLOCK) { @@ -2198,9 +2206,11 @@ static ssize_t comedi_read(struct file *file, char __user *buf, size_t nbytes, buf += n; break; /* makes device work like a pipe */ } - if (comedi_is_subdevice_idle(s) && - async->buf_read_count - async->buf_write_count == 0) { - do_become_nonbusy(dev, s); + if (comedi_is_subdevice_idle(s)) { + mutex_lock(&dev->mutex); + if (async->buf_read_count - async->buf_write_count == 0) + do_become_nonbusy(dev, s); + mutex_unlock(&dev->mutex); } set_current_state(TASK_RUNNING); remove_wait_queue(&async->wait_head, &wait); |