Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964787AbbGXRFA (ORCPT ); Fri, 24 Jul 2015 13:05:00 -0400 Received: from jabba.london.02.net ([82.132.130.169]:34366 "EHLO mail.o2.co.uk" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1753954AbbGXRE6 (ORCPT ); Fri, 24 Jul 2015 13:04:58 -0400 Message-ID: <55B26EDB.9060707@berndporr.me.uk> Date: Fri, 24 Jul 2015 17:59:07 +0100 From: Bernd Porr User-Agent: Thunderbird 2.0.0.24 (X11/20100228) MIME-Version: 1.0 To: Ian Abbott CC: driverdev-devel@linuxdriverproject.org, Greg Kroah-Hartman , H Hartley Sweeten , linux-kernel@vger.kernel.org Subject: Re: [PATCH 5/6] staging: comedi: usbduxsigma: remove unused "convert" timing for AO References: <1437666422-25222-1-git-send-email-abbotti@mev.co.uk> <1437666422-25222-6-git-send-email-abbotti@mev.co.uk> In-Reply-To: <1437666422-25222-6-git-send-email-abbotti@mev.co.uk> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4303 Lines: 115 Reviewed-by: Bernd Porr Ian Abbott wrote: > The `cmdtest` and `cmd` handlers for the AO subdevice > (`usbduxsigma_ao_cmdtest()` and `usbduxsigma_ao_cmd()`) support "scan" > timing of commands with all channels updated every "scan" period. There > is some disabled code to use "convert" timing in high speed mode. That > would allow channels to be updated sequentially every "convert" period. > Since that code is incomplete and currently disabled, remove it to > simplify the existing code. > > Signed-off-by: Ian Abbott > --- > drivers/staging/comedi/drivers/usbduxsigma.c | 58 ++++++++-------------------- > 1 file changed, 17 insertions(+), 41 deletions(-) > > diff --git a/drivers/staging/comedi/drivers/usbduxsigma.c b/drivers/staging/comedi/drivers/usbduxsigma.c > index 4655048..d97253e 100644 > --- a/drivers/staging/comedi/drivers/usbduxsigma.c > +++ b/drivers/staging/comedi/drivers/usbduxsigma.c > @@ -838,28 +838,20 @@ static int usbduxsigma_ao_cmdtest(struct comedi_device *dev, > { > struct usbduxsigma_private *devpriv = dev->private; > int err = 0; > - int high_speed; > - unsigned int flags; > - > - /* high speed conversions are not used yet */ > - high_speed = 0; /* (devpriv->high_speed) */ > > /* Step 1 : check if triggers are trivially valid */ > > err |= comedi_check_trigger_src(&cmd->start_src, TRIG_NOW | TRIG_INT); > > - if (high_speed) { > - /* > - * start immediately a new scan > - * the sampling rate is set by the coversion rate > - */ > - flags = TRIG_FOLLOW; > - } else { > - /* start a new scan (output at once) with a timer */ > - flags = TRIG_TIMER; > - } > - err |= comedi_check_trigger_src(&cmd->scan_begin_src, flags); > - > + /* > + * For now, always use "scan" timing with all channels updated at once > + * (cmd->scan_begin_src == TRIG_TIMER, cmd->convert_src == TRIG_NOW). > + * > + * In a future version, "convert" timing with channels updated > + * indivually may be supported in high speed mode > + * (cmd->scan_begin_src == TRIG_FOLLOW, cmd->convert_src == TRIG_TIMER). > + */ > + err |= comedi_check_trigger_src(&cmd->scan_begin_src, TRIG_TIMER); > err |= comedi_check_trigger_src(&cmd->convert_src, TRIG_NOW); > err |= comedi_check_trigger_src(&cmd->scan_end_src, TRIG_COUNT); > err |= comedi_check_trigger_src(&cmd->stop_src, TRIG_COUNT | TRIG_NONE); > @@ -883,17 +875,7 @@ static int usbduxsigma_ao_cmdtest(struct comedi_device *dev, > > err |= comedi_check_trigger_arg_is(&cmd->start_arg, 0); > > - if (cmd->scan_begin_src == TRIG_FOLLOW) /* internal trigger */ > - err |= comedi_check_trigger_arg_is(&cmd->scan_begin_arg, 0); > - > - if (cmd->scan_begin_src == TRIG_TIMER) { > - err |= comedi_check_trigger_arg_min(&cmd->scan_begin_arg, > - 1000000); > - } > - > - /* not used now, is for later use */ > - if (cmd->convert_src == TRIG_TIMER) > - err |= comedi_check_trigger_arg_min(&cmd->convert_arg, 125000); > + err |= comedi_check_trigger_arg_min(&cmd->scan_begin_arg, 1000000); > > err |= comedi_check_trigger_arg_is(&cmd->scan_end_arg, > cmd->chanlist_len); > @@ -918,19 +900,13 @@ static int usbduxsigma_ao_cmd(struct comedi_device *dev, > > 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; > - } > + /* > + * For now, only "scan" timing is supported. A future version may > + * support "convert" timing in high speed mode. > + * > + * Timing of the scan: every 1ms all channels updated at once. > + */ > + devpriv->ao_timer = cmd->scan_begin_arg / 1000000; > > devpriv->ao_counter = devpriv->ao_timer; > -- http://www.berndporr.me.uk http://www.linux-usb-daq.co.uk http://www.imdb.com/name/nm3293421/ +44 (0)7840 340069 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/