Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754908Ab3CATsT (ORCPT ); Fri, 1 Mar 2013 14:48:19 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:52085 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754678Ab3CATqy (ORCPT ); Fri, 1 Mar 2013 14:46:54 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Ian Abbott Subject: [ 29/30] staging: comedi: ni_labpc: set up command4 register *after* command3 Date: Fri, 1 Mar 2013 11:45:50 -0800 Message-Id: <20130301194531.168938974@linuxfoundation.org> X-Mailer: git-send-email 1.8.1.rc1.5.g7e0651a In-Reply-To: <20130301194527.988540148@linuxfoundation.org> References: <20130301194527.988540148@linuxfoundation.org> User-Agent: quilt/0.60-2.1.2 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3201 Lines: 82 3.0-stable review patch. If anyone has any objections, please let me know. ------------------ 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: Greg Kroah-Hartman --- drivers/staging/comedi/drivers/ni_labpc.c | 31 +++++++++++++++--------------- 1 file changed, 16 insertions(+), 15 deletions(-) --- a/drivers/staging/comedi/drivers/ni_labpc.c +++ b/drivers/staging/comedi/drivers/ni_labpc.c @@ -1259,21 +1259,6 @@ static int labpc_ai_cmd(struct comedi_de 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); @@ -1351,6 +1336,22 @@ static int labpc_ai_cmd(struct comedi_de 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 acquisition */ /* command2 reg */ -- 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/