From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752953AbbJBNZi (ORCPT ); Fri, 2 Oct 2015 09:25:38 -0400 Received: from mx2.suse.de ([195.135.220.15]:39533 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752811AbbJBNZc (ORCPT ); Fri, 2 Oct 2015 09:25:32 -0400 X-Amavis-Alert: BAD HEADER SECTION, Duplicate header field: "References" From: Jiri Slaby To: stable@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Ian Abbott , Jiri Slaby Subject: [PATCH 3.12 04/84] staging: comedi: usbduxsigma: don't clobber ao_timer in command test Date: Fri, 2 Oct 2015 15:24:09 +0200 Message-Id: <92ca2aaa4cc43fd8bb1cd018d7183a2d68352b2e.1443792303.git.jslaby@suse.cz> X-Mailer: git-send-email 2.6.0 In-Reply-To: <4386f737d429451d61358f771e315ed47e2f451f.1443792303.git.jslaby@suse.cz> References: <4386f737d429451d61358f771e315ed47e2f451f.1443792303.git.jslaby@suse.cz> In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Ian Abbott 3.12-stable review patch. If anyone has any objections, please let me know. =============== 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` and `devpriv->ao_continuous` 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: Jiri Slaby --- drivers/staging/comedi/drivers/usbduxsigma.c | 41 ++++++++++++---------------- 1 file changed, 17 insertions(+), 24 deletions(-) diff --git a/drivers/staging/comedi/drivers/usbduxsigma.c b/drivers/staging/comedi/drivers/usbduxsigma.c index c61a1b9d7cd8..580c1358eb84 100644 --- a/drivers/staging/comedi/drivers/usbduxsigma.c +++ b/drivers/staging/comedi/drivers/usbduxsigma.c @@ -950,10 +950,24 @@ static int usbduxsigma_ao_cmdtest(struct comedi_device *dev, if (err) return 3; - /* Step 4: fix up any arguments */ + 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; + int i; + + down(&devpriv->sem); + + /* set current channel of the running acquisition to zero */ + s->async->cur_chan = 0; /* we count in timer steps */ - if (high_speed) { + if (cmd->convert_src == TRIG_TIMER) { /* timing of the conversion itself: every 125 us */ devpriv->ao_timer = cmd->convert_arg / 125000; } else { @@ -963,12 +977,9 @@ 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; @@ -987,24 +998,6 @@ 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; - int i; - - down(&devpriv->sem); - - /* set current channel of the running acquisition to zero */ - s->async->cur_chan = 0; for (i = 0; i < cmd->chanlist_len; ++i) devpriv->ao_chanlist[i] = CR_CHAN(cmd->chanlist[i]); -- 2.6.0