From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:43938 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752290AbbIPAaV (ORCPT ); Tue, 15 Sep 2015 20:30:21 -0400 Subject: Patch "staging: comedi: usbduxsigma: don't clobber ao_timer in command test" has been added to the 4.2-stable tree To: abbotti@mev.co.uk, gregkh@linuxfoundation.org, hsweeten@visionengravers.com, mail@berndporr.me.uk Cc: , From: Date: Tue, 15 Sep 2015 17:30:21 -0700 Message-ID: <144236342111820@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: This is a note to let you know that I've just added the patch titled staging: comedi: usbduxsigma: don't clobber ao_timer in command test to the 4.2-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: staging-comedi-usbduxsigma-don-t-clobber-ao_timer-in-command-test.patch and it can be found in the queue-4.2 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From c04a1f17803e0d3eeada586ca34a6b436959bc20 Mon Sep 17 00:00:00 2001 From: Ian Abbott Date: Thu, 23 Jul 2015 16:46:58 +0100 Subject: staging: comedi: usbduxsigma: don't clobber ao_timer in command test 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()`. 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 Reviewed-by: Bernd Porr Reviewed-by: H Hartley Sweeten Signed-off-by: Greg Kroah-Hartman --- drivers/staging/comedi/drivers/usbduxsigma.c | 33 +++++++++++---------------- 1 file changed, 14 insertions(+), 19 deletions(-) --- a/drivers/staging/comedi/drivers/usbduxsigma.c +++ b/drivers/staging/comedi/drivers/usbduxsigma.c @@ -912,25 +912,6 @@ static int usbduxsigma_ao_cmdtest(struct if (err) return 3; - /* Step 4: fix up any arguments */ - - /* we count in timer steps */ - if (high_speed) { - /* timing of the conversion itself: every 125 us */ - devpriv->ao_timer = cmd->convert_arg / 125000; - } else { - /* - * timing of the scan: every 1ms - * we get all channels at once - */ - devpriv->ao_timer = cmd->scan_begin_arg / 1000000; - } - if (devpriv->ao_timer < 1) - err |= -EINVAL; - - if (err) - return 4; - return 0; } @@ -943,6 +924,20 @@ static int usbduxsigma_ao_cmd(struct com down(&devpriv->sem); + 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 { + /* + * timing of the scan: every 1ms + * we get all channels at once + */ + devpriv->ao_timer = cmd->scan_begin_arg / 1000000; + } + devpriv->ao_counter = devpriv->ao_timer; if (cmd->start_src == TRIG_NOW) { Patches currently in stable-queue which might be from abbotti@mev.co.uk are queue-4.2/staging-comedi-usbduxsigma-don-t-clobber-ao_timer-in-command-test.patch queue-4.2/staging-comedi-adl_pci7x3x-fix-digital-output-on-pci-7230.patch queue-4.2/staging-comedi-usbduxsigma-don-t-clobber-ai_timer-in-command-test.patch