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authorIan Abbott <abbotti@mev.co.uk>2015-11-18 17:55:09 +0000
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2015-12-21 15:58:54 -0800
commit40d0e80e08012ac99b187cbaaeb8aab92b71714d (patch)
tree779e97ea7e0188c9418f959f3dc4780b5c1f9ddd /drivers
parent35a7475dc818320915e89ed0217872ff1ab66ec2 (diff)
staging: comedi: return error on "write" if no command set up
The "write" file operation handler, `comedi_write()` returns an error for pretty much any condition that prevents a "write" going ahead. One of the conditions that prevents a "write" going ahead is that no asynchronous command has been set up, but that currently results in a return value of 0 (unless COMEDI instructions are being processed or an asynchronous command has been set up by a different file object). Change it to return `-EINVAL` in this case. Signed-off-by: Ian Abbott <abbotti@mev.co.uk> Reviewed-by: H Hartley Sweeten <hsweeten@visionengravers.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/staging/comedi/comedi_fops.c11
1 files changed, 8 insertions, 3 deletions
diff --git a/drivers/staging/comedi/comedi_fops.c b/drivers/staging/comedi/comedi_fops.c
index 4dd42890c641..2a2b5a06ed0e 100644
--- a/drivers/staging/comedi/comedi_fops.c
+++ b/drivers/staging/comedi/comedi_fops.c
@@ -2331,9 +2331,12 @@ static ssize_t comedi_write(struct file *file, const char __user *buf,
}
async = s->async;
-
- if (!s->busy || !nbytes)
+ if (!nbytes)
+ goto out;
+ if (!s->busy) {
+ retval = -EINVAL;
goto out;
+ }
if (s->busy != file) {
retval = -EACCES;
goto out;
@@ -2373,8 +2376,10 @@ static ssize_t comedi_write(struct file *file, const char __user *buf,
retval = -ERESTARTSYS;
break;
}
- if (!s->busy)
+ if (!s->busy) {
+ retval = -EINVAL;
break;
+ }
if (s->busy != file) {
retval = -EACCES;
break;