From 39582847757ef79fb9de2661dd9297f1c988478d Mon Sep 17 00:00:00 2001 From: Ian Abbott Date: Mon, 12 Oct 2015 17:21:28 +0100 Subject: [PATCH] staging: comedi: simplify returned errors for comedi_read() In order to perform a "read" file operation, an asynchronous COMEDI command in the "read" direction needs to have been set up by the current file object on the COMEDI "read" subdevice associated with the file object. If there is a "read" subdevice, but a command has not been set up by the file object (or is has been set-up in the wrong direction), `comedi_read()` 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 Reviewed-by: H Hartley Sweeten Signed-off-by: Greg Kroah-Hartman --- drivers/staging/comedi/comedi_fops.c | 21 +++------------------ 1 file changed, 3 insertions(+), 18 deletions(-) diff --git a/drivers/staging/comedi/comedi_fops.c b/drivers/staging/comedi/comedi_fops.c index 190592a..466dc95 100644 --- a/drivers/staging/comedi/comedi_fops.c +++ b/drivers/staging/comedi/comedi_fops.c @@ -2480,15 +2480,7 @@ static ssize_t comedi_read(struct file *file, char __user *buf, size_t nbytes, 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; } @@ -2520,15 +2512,8 @@ static ssize_t comedi_read(struct file *file, char __user *buf, size_t nbytes, 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; } -- 2.7.4