From 333e40aee3f2d0457e2cbadc742619a6f449b2e7 Mon Sep 17 00:00:00 2001 From: Ian Abbott Date: Thu, 23 Jul 2015 16:47:00 +0100 Subject: [PATCH] staging: comedi: usbduxsigma: round down AI scan_begin_arg at step 4. The return value of the `cmdtest` handler for a subdevice checks the prospective new command in various steps and returns the step number at which any problem was detected, or 0 if no problem was detected. It is allowed to modify the command in various ways at each step. Corrections for out-of-range values are generally made at step 3, and minor adjustments such as rounding are generally made at step 4. The `cmdtest` handler for the AI subdevice (`usbduxsigma_ai_cmdtest()`) currently modifies `cmd->scan_begin_arg` to bring it into range and round it down at step 3. Move the rounding down part to step 4 to follow the usual Comedi convention. Signed-off-by: Ian Abbott Reviewed-by: Bernd Porr Reviewed-by: H Hartley Sweeten Signed-off-by: Greg Kroah-Hartman --- drivers/staging/comedi/drivers/usbduxsigma.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-) diff --git a/drivers/staging/comedi/drivers/usbduxsigma.c b/drivers/staging/comedi/drivers/usbduxsigma.c index fdc880a..535cf01b 100644 --- a/drivers/staging/comedi/drivers/usbduxsigma.c +++ b/drivers/staging/comedi/drivers/usbduxsigma.c @@ -519,17 +519,12 @@ static int usbduxsigma_ai_cmdtest(struct comedi_device *dev, */ err |= comedi_check_trigger_arg_min(&cmd->scan_begin_arg, (125000 * interval)); - - tmp = (cmd->scan_begin_arg / 125000) * 125000; } else { /* full speed */ /* 1kHz scans every USB frame */ err |= comedi_check_trigger_arg_min(&cmd->scan_begin_arg, 1000000); - - tmp = (cmd->scan_begin_arg / 1000000) * 1000000; } - err |= comedi_check_trigger_arg_is(&cmd->scan_begin_arg, tmp); err |= comedi_check_trigger_arg_is(&cmd->scan_end_arg, cmd->chanlist_len); @@ -542,6 +537,14 @@ static int usbduxsigma_ai_cmdtest(struct comedi_device *dev, if (err) return 3; + /* Step 4: fix up any arguments */ + + tmp = rounddown(cmd->scan_begin_arg, high_speed ? 125000 : 1000000); + err |= comedi_check_trigger_arg_is(&cmd->scan_begin_arg, tmp); + + if (err) + return 4; + return 0; } -- 2.7.4