From 1a02387063fbd32f51c98540499b90acc8b4317f Mon Sep 17 00:00:00 2001 From: H Hartley Sweeten Date: Wed, 5 Aug 2015 10:44:42 -0700 Subject: [PATCH] staging: comedi: me4000: remove 'board' from me4000_ai_insn_read() The 'board' pointer is only used in this function to verify that the 'chan' is valid for an aref of AREF_DIFF. For differential inputs, the maximum channel is half the subdevice 'n_chan'. Use that instead and remove the 'board' variable. Also, the comedi core does not validate the aref flags. Add a check to ensure that the subdevice actually supports the AREF_DIFF mode. Signed-off-by: H Hartley Sweeten Reviewed-by: Ian Abbott Signed-off-by: Greg Kroah-Hartman --- drivers/staging/comedi/drivers/me4000.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-) diff --git a/drivers/staging/comedi/drivers/me4000.c b/drivers/staging/comedi/drivers/me4000.c index d6b7adc19056..335fafc73a94 100644 --- a/drivers/staging/comedi/drivers/me4000.c +++ b/drivers/staging/comedi/drivers/me4000.c @@ -436,10 +436,10 @@ static void me4000_reset(struct comedi_device *dev) ===========================================================================*/ static int me4000_ai_insn_read(struct comedi_device *dev, - struct comedi_subdevice *subdevice, - struct comedi_insn *insn, unsigned int *data) + struct comedi_subdevice *s, + struct comedi_insn *insn, + unsigned int *data) { - const struct me4000_board *board = dev->board_ptr; int chan = CR_CHAN(insn->chanspec); int rang = CR_RANGE(insn->chanspec); int aref = CR_AREF(insn->chanspec); @@ -481,13 +481,19 @@ static int me4000_ai_insn_read(struct comedi_device *dev, break; case AREF_DIFF: + if (!(s->subdev_flags && SDF_DIFF)) { + dev_err(dev->class_dev, + "Differential inputs are not available\n"); + return -EINVAL; + } + if (rang == 0 || rang == 1) { dev_err(dev->class_dev, "Range must be bipolar when aref = diff\n"); return -EINVAL; } - if (chan >= board->ai_diff_nchan) { + if (chan >= (s->n_chan / 2)) { dev_err(dev->class_dev, "Analog input is not available\n"); return -EINVAL; -- 2.20.1