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authorIan Abbott <abbotti@mev.co.uk>2015-11-18 17:55:10 +0000
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2015-12-21 15:58:54 -0800
commit3318c7add8b43a071498a973548dd24b55c587d4 (patch)
tree181e0ed5c02e2115fcef85c2423d002850f416f4 /drivers/staging/comedi
parent40d0e80e08012ac99b187cbaaeb8aab92b71714d (diff)
downloadlinux-3318c7add8b43a071498a973548dd24b55c587d4.tar.bz2
staging: comedi: simplify returned errors for comedi_write()
In order to perform a "write" file operation, an asynchronous COMEDI command in the "write" direction needs to have been set up by the current file object on the COMEDI "write" subdevice associated with the file object. If there is a "write" subdevice, but a command has not been set up by the file object (or is has been set-up in the wrong direction), `comedi_write()` currently returns one of two error values `-EINVAL` or `-EACCES`. `-EACCES` is returned if the command was set up by a different subdevice, or somewhat randomly, if a COMEDI "instruction" is currently being processed. `-EINVAL` is returned in other cases. Simplify it by returning `-EINVAL` for all these cases. 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/staging/comedi')
-rw-r--r--drivers/staging/comedi/comedi_fops.c21
1 files changed, 3 insertions, 18 deletions
diff --git a/drivers/staging/comedi/comedi_fops.c b/drivers/staging/comedi/comedi_fops.c
index 2a2b5a06ed0e..5a9c9d9782f3 100644
--- a/drivers/staging/comedi/comedi_fops.c
+++ b/drivers/staging/comedi/comedi_fops.c
@@ -2333,15 +2333,7 @@ static ssize_t comedi_write(struct file *file, const char __user *buf,
async = s->async;
if (!nbytes)
goto out;
- if (!s->busy) {
- retval = -EINVAL;
- goto out;
- }
- if (s->busy != file) {
- retval = -EACCES;
- goto out;
- }
- if (!(async->cmd.flags & CMDF_WRITE)) {
+ if (s->busy != file || !(async->cmd.flags & CMDF_WRITE)) {
retval = -EINVAL;
goto out;
}
@@ -2376,15 +2368,8 @@ static ssize_t comedi_write(struct file *file, const char __user *buf,
retval = -ERESTARTSYS;
break;
}
- if (!s->busy) {
- retval = -EINVAL;
- break;
- }
- if (s->busy != file) {
- retval = -EACCES;
- break;
- }
- if (!(async->cmd.flags & CMDF_WRITE)) {
+ if (s->busy != file ||
+ !(async->cmd.flags & CMDF_WRITE)) {
retval = -EINVAL;
break;
}