From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1427689AbcBSQP4 (ORCPT ); Fri, 19 Feb 2016 11:15:56 -0500 Received: from smtp73.iad3a.emailsrvr.com ([173.203.187.73]:47953 "EHLO smtp73.iad3a.emailsrvr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1949172AbcBSQOM (ORCPT ); Fri, 19 Feb 2016 11:14:12 -0500 X-Auth-ID: abbotti@mev.co.uk X-Sender-Id: abbotti@mev.co.uk From: Ian Abbott To: devel@driverdev.osuosl.org Cc: Greg Kroah-Hartman , Ian Abbott , H Hartley Sweeten , linux-kernel@vger.kernel.org Subject: [PATCH 5/8] staging: comedi: COMEDI_BUFINFO: return error if no active command Date: Fri, 19 Feb 2016 16:13:54 +0000 Message-Id: <1455898437-4640-6-git-send-email-abbotti@mev.co.uk> X-Mailer: git-send-email 2.7.0 In-Reply-To: <1455898437-4640-1-git-send-email-abbotti@mev.co.uk> References: <1455898437-4640-1-git-send-email-abbotti@mev.co.uk> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The `COMEDI_BUFINFO` ioctl is used to advance the current position in the buffer and/or get the current buffer position. If no asynchronous command is active (started via the file object that issued this ioctl), this information is meaningless. Change it to return an error (`-EINVAL`) in this case. Prior to this change, if a command was started via a different file object, the ioctl returned `-EACCES`, but now it will return `-EINVAL`, which is consistent with the current behavior of the "read" and "write" file operation handlers. Signed-off-by: Ian Abbott --- drivers/staging/comedi/comedi_fops.c | 22 ++-------------------- 1 file changed, 2 insertions(+), 20 deletions(-) diff --git a/drivers/staging/comedi/comedi_fops.c b/drivers/staging/comedi/comedi_fops.c index b7c9270..a9fabf7 100644 --- a/drivers/staging/comedi/comedi_fops.c +++ b/drivers/staging/comedi/comedi_fops.c @@ -1123,24 +1123,8 @@ static int do_bufinfo_ioctl(struct comedi_device *dev, async = s->async; - if (!async) { - dev_dbg(dev->class_dev, - "subdevice does not have async capability\n"); - bi.buf_write_ptr = 0; - bi.buf_read_ptr = 0; - bi.buf_write_count = 0; - bi.buf_read_count = 0; - bi.bytes_read = 0; - bi.bytes_written = 0; - goto copyback; - } - if (!s->busy) { - bi.bytes_read = 0; - bi.bytes_written = 0; - goto copyback_position; - } - if (s->busy != file) - return -EACCES; + if (!async || s->busy != file) + return -EINVAL; if (!(async->cmd.flags & CMDF_WRITE)) { /* command was set up in "read" direction */ @@ -1165,7 +1149,6 @@ static int do_bufinfo_ioctl(struct comedi_device *dev, bi.bytes_read = 0; } -copyback_position: bi.buf_write_count = async->buf_write_count; bi.buf_write_ptr = async->buf_write_ptr; bi.buf_read_count = async->buf_read_count; @@ -1174,7 +1157,6 @@ copyback_position: if (become_nonbusy) do_become_nonbusy(dev, s); -copyback: if (copy_to_user(arg, &bi, sizeof(bi))) return -EFAULT; -- 2.7.0