From patchwork Wed Sep 30 09:49:21 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Luis Henriques X-Patchwork-Id: 524224 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from huckleberry.canonical.com (huckleberry.canonical.com [91.189.94.19]) by ozlabs.org (Postfix) with ESMTP id 9B10E140D21; Wed, 30 Sep 2015 19:53:45 +1000 (AEST) Received: from localhost ([127.0.0.1] helo=huckleberry.canonical.com) by huckleberry.canonical.com with esmtp (Exim 4.76) (envelope-from ) id 1ZhE4z-0008M4-AO; Wed, 30 Sep 2015 09:53:41 +0000 Received: from youngberry.canonical.com ([91.189.89.112]) by huckleberry.canonical.com with esmtp (Exim 4.76) (envelope-from ) id 1ZhE3G-0007Ed-7s for kernel-team@lists.ubuntu.com; Wed, 30 Sep 2015 09:51:54 +0000 Received: from av-217-129-142-138.netvisao.pt ([217.129.142.138] helo=localhost) by youngberry.canonical.com with esmtpsa (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.76) (envelope-from ) id 1ZhE3G-0005vT-3f; Wed, 30 Sep 2015 09:51:54 +0000 From: Luis Henriques To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Subject: [PATCH 3.16.y-ckt 013/133] staging: comedi: usbduxsigma: don't clobber ao_timer in command test Date: Wed, 30 Sep 2015 10:49:21 +0100 Message-Id: <1443606681-7124-14-git-send-email-luis.henriques@canonical.com> X-Mailer: git-send-email 2.1.4 In-Reply-To: <1443606681-7124-1-git-send-email-luis.henriques@canonical.com> References: <1443606681-7124-1-git-send-email-luis.henriques@canonical.com> X-Extended-Stable: 3.16 Cc: Ian Abbott X-BeenThere: kernel-team@lists.ubuntu.com X-Mailman-Version: 2.1.14 Precedence: list List-Id: Kernel team discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: kernel-team-bounces@lists.ubuntu.com Sender: kernel-team-bounces@lists.ubuntu.com 3.16.7-ckt18 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Ian Abbott commit c04a1f17803e0d3eeada586ca34a6b436959bc20 upstream. `devpriv->ao_timer` is used while an asynchronous command is running on the AO subdevice. It also gets modified by the subdevice's `cmdtest` handler for checking new asynchronous commands, `usbduxsigma_ao_cmdtest()`, which is not correct as it's allowed to check new commands while an old command is still running. Fix it by moving the code which sets up `devpriv->ao_timer` into the subdevice's `cmd` handler, `usbduxsigma_ao_cmd()`. ** This backported patch also moves the code that sets up `devpriv->ao_sample_count` from `usbduxsigma_ao_cmdtest()` to `usbduxsigma_ao_cmd()` for the same reason as above. (This was not needed in the upstream commit.) ** Note that the removed code in `usbduxsigma_ao_cmdtest()` checked that `devpriv->ao_timer` did not end up less that 1, but that could not happen due because `cmd->scan_begin_arg` or `cmd->convert_arg` had already been range-checked. Also note that we tested the `high_speed` variable in the old code, but that is currently always 0 and means that we always use "scan" timing (`cmd->scan_begin_src == TRIG_TIMER` and `cmd->convert_src == TRIG_NOW`) and never "convert" (individual sample) timing (`cmd->scan_begin_src == TRIG_FOLLOW` and `cmd->convert_src == TRIG_TIMER`). The moved code tests `cmd->convert_src` instead to decide whether "scan" or "convert" timing is being used, although currently only "scan" timing is supported. Fixes: fb1ef622e7a3 ("staging: comedi: usbduxsigma: tidy up analog output command support") Signed-off-by: Ian Abbott Signed-off-by: Luis Henriques --- drivers/staging/comedi/drivers/usbduxsigma.c | 46 ++++++++++++---------------- 1 file changed, 20 insertions(+), 26 deletions(-) diff --git a/drivers/staging/comedi/drivers/usbduxsigma.c b/drivers/staging/comedi/drivers/usbduxsigma.c index e2c0c54e0910..823ccf6fef66 100644 --- a/drivers/staging/comedi/drivers/usbduxsigma.c +++ b/drivers/staging/comedi/drivers/usbduxsigma.c @@ -946,11 +946,26 @@ static int usbduxsigma_ao_cmdtest(struct comedi_device *dev, if (err) return 3; - /* Step 4: fix up any arguments */ + return 0; +} - /* we count in timer steps */ - if (high_speed) { - /* timing of the conversion itself: every 125 us */ +static int usbduxsigma_ao_cmd(struct comedi_device *dev, + struct comedi_subdevice *s) +{ + struct usbduxsigma_private *devpriv = dev->private; + struct comedi_cmd *cmd = &s->async->cmd; + int ret; + + down(&devpriv->sem); + + /* set current channel of the running acquisition to zero */ + s->async->cur_chan = 0; + + if (cmd->convert_src == TRIG_TIMER) { + /* + * timing of the conversion itself: every 125 us + * at high speed (not used yet) + */ devpriv->ao_timer = cmd->convert_arg / 125000; } else { /* @@ -959,12 +974,9 @@ static int usbduxsigma_ao_cmdtest(struct comedi_device *dev, */ devpriv->ao_timer = cmd->scan_begin_arg / 1000000; } - if (devpriv->ao_timer < 1) - err |= -EINVAL; - if (cmd->stop_src == TRIG_COUNT) { /* not continuous, use counter */ - if (high_speed) { + if (cmd->convert_src == TRIG_TIMER) { /* high speed also scans everything at once */ devpriv->ao_sample_count = cmd->stop_arg * cmd->scan_end_arg; @@ -981,24 +993,6 @@ static int usbduxsigma_ao_cmdtest(struct comedi_device *dev, devpriv->ao_sample_count = 0; } - if (err) - return 4; - - return 0; -} - -static int usbduxsigma_ao_cmd(struct comedi_device *dev, - struct comedi_subdevice *s) -{ - struct usbduxsigma_private *devpriv = dev->private; - struct comedi_cmd *cmd = &s->async->cmd; - int ret; - - down(&devpriv->sem); - - /* set current channel of the running acquisition to zero */ - s->async->cur_chan = 0; - devpriv->ao_counter = devpriv->ao_timer; if (cmd->start_src == TRIG_NOW) {