From patchwork Thu Feb 28 14:44:48 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Luis Henriques X-Patchwork-Id: 224105 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from huckleberry.canonical.com (huckleberry.canonical.com [91.189.94.19]) by ozlabs.org (Postfix) with ESMTP id A59E32C029D for ; Fri, 1 Mar 2013 01:51:53 +1100 (EST) Received: from localhost ([127.0.0.1] helo=huckleberry.canonical.com) by huckleberry.canonical.com with esmtp (Exim 4.76) (envelope-from ) id 1UB4ph-0000xn-A5; Thu, 28 Feb 2013 14:51:41 +0000 Received: from youngberry.canonical.com ([91.189.89.112]) by huckleberry.canonical.com with esmtp (Exim 4.76) (envelope-from ) id 1UB4pZ-0000pd-Dw for kernel-team@lists.ubuntu.com; Thu, 28 Feb 2013 14:51:33 +0000 Received: from [188.250.143.69] (helo=localhost) by youngberry.canonical.com with esmtpsa (TLS1.0:DHE_RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1UB4pY-0001Xd-TJ; Thu, 28 Feb 2013 14:51:33 +0000 From: Luis Henriques To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Subject: [PATCH 138/139] staging: comedi: ni_labpc: set up command4 register *after* command3 Date: Thu, 28 Feb 2013 14:44:48 +0000 Message-Id: <1362062689-2567-139-git-send-email-luis.henriques@canonical.com> X-Mailer: git-send-email 1.8.1.2 In-Reply-To: <1362062689-2567-1-git-send-email-luis.henriques@canonical.com> References: <1362062689-2567-1-git-send-email-luis.henriques@canonical.com> X-Extended-Stable: 3.5 Cc: Ian Abbott X-BeenThere: kernel-team@lists.ubuntu.com X-Mailman-Version: 2.1.14 Precedence: list List-Id: Kernel team discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: kernel-team-bounces@lists.ubuntu.com Sender: kernel-team-bounces@lists.ubuntu.com 3.5.7.7 -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: Luis Henriques --- 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 5334977..5b2b966 100644 --- a/drivers/staging/comedi/drivers/ni_labpc.c +++ b/drivers/staging/comedi/drivers/ni_labpc.c @@ -1275,21 +1275,6 @@ 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); @@ -1369,6 +1354,22 @@ 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 acquisition */ /* command2 reg */