From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from youngberry.canonical.com ([91.189.89.112]:43510 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932798AbbIVSrd (ORCPT ); Tue, 22 Sep 2015 14:47:33 -0400 Date: Tue, 22 Sep 2015 19:47:31 +0100 From: Luis Henriques To: Jiri Slaby Cc: stable@vger.kernel.org, Ian Abbott Subject: Re: [patch added to the 3.12 stable tree] staging: comedi: usbduxsigma: don't clobber ai_timer in command test Message-ID: <20150922184731.GA13426@charon> References: <1442432295-7805-1-git-send-email-jslaby@suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <1442432295-7805-1-git-send-email-jslaby@suse.cz> Sender: stable-owner@vger.kernel.org List-ID: On Wed, Sep 16, 2015 at 09:38:12PM +0200, Jiri Slaby wrote: > From: Ian Abbott > > This patch has been added to the 3.12 stable tree. If you have any > objections, please let us know. > Please note that this commit (and the next one) were tagged for kernels >= 3.19. Cheers, -- Lu�s > =============== > > commit 423b24c37dd5794a674c74b0ed56392003a69891 upstream > > `devpriv->ai_timer` is used while an asynchronous command is running on > the AI subdevice. It also gets modified by the subdevice's `cmdtest` > handler for checking new asynchronous commands > (`usbduxsigma_ai_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->ai_timer` and > `devpriv->ai_interval` into the subdevice's `cmd` handler, > `usbduxsigma_ai_cmd()`. > > ** This backported patch also moves the code that sets up > `devpriv->ai_sample_count` and `devpriv->ai_continuous` from > `usbduxsigma_ai_cmdtest()` to `usbduxsigma_ai_cmd()` for the same reason > as above. (This was not needed in the upstream commit.) ** > > Note that the removed code in `usbduxsigma_ai_cmdtest()` checked that > `devpriv->ai_timer` did not end up less than than 1, but that could not > happen because `cmd->scan_begin_arg` had already been checked to be at > least the minimum required value (at least when `cmd->scan_begin_src == > TRIG_TIMER`, which had also been checked to be the case). > > Fixes: b986be8527c7 ("staging: comedi: usbduxsigma: tidy up analog input command support) > Signed-off-by: Ian Abbott > Signed-off-by: Jiri Slaby > --- > drivers/staging/comedi/drivers/usbduxsigma.c | 58 +++++++++++++--------------- > 1 file changed, 27 insertions(+), 31 deletions(-) > > diff --git a/drivers/staging/comedi/drivers/usbduxsigma.c b/drivers/staging/comedi/drivers/usbduxsigma.c > index c47f4087568f..c61a1b9d7cd8 100644 > --- a/drivers/staging/comedi/drivers/usbduxsigma.c > +++ b/drivers/staging/comedi/drivers/usbduxsigma.c > @@ -575,37 +575,6 @@ static int usbduxsigma_ai_cmdtest(struct comedi_device *dev, > if (err) > return 3; > > - /* Step 4: fix up any arguments */ > - > - if (high_speed) { > - /* > - * every 2 channels get a time window of 125us. Thus, if we > - * sample all 16 channels we need 1ms. If we sample only one > - * channel we need only 125us > - */ > - devpriv->ai_interval = interval; > - devpriv->ai_timer = cmd->scan_begin_arg / (125000 * interval); > - } else { > - /* interval always 1ms */ > - devpriv->ai_interval = 1; > - devpriv->ai_timer = cmd->scan_begin_arg / 1000000; > - } > - if (devpriv->ai_timer < 1) > - err |= -EINVAL; > - > - if (cmd->stop_src == TRIG_COUNT) { > - /* data arrives as one packet */ > - devpriv->ai_sample_count = cmd->stop_arg; > - devpriv->ai_continuous = 0; > - } else { > - /* continuous acquisition */ > - devpriv->ai_continuous = 1; > - devpriv->ai_sample_count = 0; > - } > - > - if (err) > - return 4; > - > return 0; > } > > @@ -704,6 +673,33 @@ static int usbduxsigma_ai_cmd(struct comedi_device *dev, > > /* set current channel of the running acquisition to zero */ > s->async->cur_chan = 0; > + > + if (devpriv->high_speed) { > + /* > + * every 2 channels get a time window of 125us. Thus, if we > + * sample all 16 channels we need 1ms. If we sample only one > + * channel we need only 125us > + */ > + unsigned int interval = usbduxsigma_chans_to_interval(len); > + > + devpriv->ai_interval = interval; > + devpriv->ai_timer = cmd->scan_begin_arg / (125000 * interval); > + } else { > + /* interval always 1ms */ > + devpriv->ai_interval = 1; > + devpriv->ai_timer = cmd->scan_begin_arg / 1000000; > + } > + > + if (cmd->stop_src == TRIG_COUNT) { > + /* data arrives as one packet */ > + devpriv->ai_sample_count = cmd->stop_arg; > + devpriv->ai_continuous = 0; > + } else { > + /* continuous acquisition */ > + devpriv->ai_continuous = 1; > + devpriv->ai_sample_count = 0; > + } > + > for (i = 0; i < len; i++) { > unsigned int chan = CR_CHAN(cmd->chanlist[i]); > > -- > 2.5.2 > > -- > To unsubscribe from this list: send the line "unsubscribe stable" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html