From 4ec85dadb7c7bb6cf84f18b7207f60efe0095d72 Mon Sep 17 00:00:00 2001 From: H Hartley Sweeten Date: Wed, 5 Aug 2015 10:44:43 -0700 Subject: [PATCH] staging: comedi: me4000: remove 'board' from me4000_ai_check_chanlist() The maximum differential channel is half the subdevice 'n_chan'. Use that instead and remove the need for the 'board' variable. Also, the comedi core does no 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 | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/drivers/staging/comedi/drivers/me4000.c b/drivers/staging/comedi/drivers/me4000.c index 335fafc..008929e 100644 --- a/drivers/staging/comedi/drivers/me4000.c +++ b/drivers/staging/comedi/drivers/me4000.c @@ -568,8 +568,6 @@ static int me4000_ai_check_chanlist(struct comedi_device *dev, struct comedi_subdevice *s, struct comedi_cmd *cmd) { - const struct me4000_board *board = dev->board_ptr; - unsigned int max_diff_chan = board->ai_diff_nchan; unsigned int aref0 = CR_AREF(cmd->chanlist[0]); int i; @@ -585,7 +583,13 @@ static int me4000_ai_check_chanlist(struct comedi_device *dev, } if (aref == AREF_DIFF) { - if (chan >= max_diff_chan) { + if (!(s->subdev_flags && SDF_DIFF)) { + dev_err(dev->class_dev, + "Differential inputs are not available\n"); + return -EINVAL; + } + + if (chan >= (s->n_chan / 2)) { dev_dbg(dev->class_dev, "Channel number to high\n"); return -EINVAL; -- 2.7.4