From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755368Ab3FDXMm (ORCPT ); Tue, 4 Jun 2013 19:12:42 -0400 Received: from 1wt.eu ([62.212.114.60]:35446 "EHLO 1wt.eu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752996Ab3FDWmU (ORCPT ); Tue, 4 Jun 2013 18:42:20 -0400 Message-Id: <20130604172133.125203398@1wt.eu> User-Agent: quilt/0.48-1 Date: Tue, 04 Jun 2013 19:22:38 +0200 From: Willy Tarreau To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Ian Abbott , Willy Tarreau Subject: [ 068/184] staging: comedi: ni_labpc: set up command4 register In-Reply-To: <58df134a4b98edf5b0073e2e1e988fe6@local> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2.6.32-longterm review patch. If anyone has any objections, please let me know. ------------------ *after* command3 From: Ian Abbott Commit 22056e2b46246d97ff0f7c6e21a77b8daa07f02c upstream. Tuomas reported problems getting meaningful output from a Lab-PC+ in differential mode for AI cmds, but AI insn reads gave correct readings. He tracked it down to two problems, one of which is addressed by this patch. It seems that writing to the command3 register after writing to the command4 register in `labpc_ai_cmd()` messes up the differential reference bit setting in the command4 register. Set up the command4 register after the command3 register (as in `labpc_ai_rinsn()`) to avoid the problem. Thanks to Tuomas for suggesting the fix. Signed-off-by: Ian Abbott Signed-off-by: Willy Tarreau --- drivers/staging/comedi/drivers/ni_labpc.c | 31 ++++++++++++++++--------------- 1 file changed, 16 insertions(+), 15 deletions(-) diff --git a/drivers/staging/comedi/drivers/ni_labpc.c b/drivers/staging/comedi/drivers/ni_labpc.c index eada2ce..76ca73a 100644 --- a/drivers/staging/comedi/drivers/ni_labpc.c +++ b/drivers/staging/comedi/drivers/ni_labpc.c @@ -1195,21 +1195,6 @@ static int labpc_ai_cmd(struct comedi_device *dev, struct comedi_subdevice *s) devpriv->write_byte(devpriv->command1_bits, dev->iobase + COMMAND1_REG); } - /* setup any external triggering/pacing (command4 register) */ - devpriv->command4_bits = 0; - if (cmd->convert_src != TRIG_EXT) - devpriv->command4_bits |= EXT_CONVERT_DISABLE_BIT; - /* XXX should discard first scan when using interval scanning - * since manual says it is not synced with scan clock */ - if (labpc_use_continuous_mode(cmd) == 0) { - devpriv->command4_bits |= INTERVAL_SCAN_EN_BIT; - if (cmd->scan_begin_src == TRIG_EXT) - devpriv->command4_bits |= EXT_SCAN_EN_BIT; - } - /* single-ended/differential */ - if (aref == AREF_DIFF) - devpriv->command4_bits |= ADC_DIFF_BIT; - devpriv->write_byte(devpriv->command4_bits, dev->iobase + COMMAND4_REG); devpriv->write_byte(cmd->chanlist_len, dev->iobase + INTERVAL_COUNT_REG); @@ -1287,6 +1272,22 @@ static int labpc_ai_cmd(struct comedi_device *dev, struct comedi_subdevice *s) devpriv->command3_bits &= ~ADC_FNE_INTR_EN_BIT; devpriv->write_byte(devpriv->command3_bits, dev->iobase + COMMAND3_REG); + /* setup any external triggering/pacing (command4 register) */ + devpriv->command4_bits = 0; + if (cmd->convert_src != TRIG_EXT) + devpriv->command4_bits |= EXT_CONVERT_DISABLE_BIT; + /* XXX should discard first scan when using interval scanning + * since manual says it is not synced with scan clock */ + if (labpc_use_continuous_mode(cmd) == 0) { + devpriv->command4_bits |= INTERVAL_SCAN_EN_BIT; + if (cmd->scan_begin_src == TRIG_EXT) + devpriv->command4_bits |= EXT_SCAN_EN_BIT; + } + /* single-ended/differential */ + if (aref == AREF_DIFF) + devpriv->command4_bits |= ADC_DIFF_BIT; + devpriv->write_byte(devpriv->command4_bits, dev->iobase + COMMAND4_REG); + /* startup aquisition */ /* command2 reg */ -- 1.7.12.2.21.g234cd45.dirty