From 2b56b35820eee978c9f4bee7e40e18ddb3d9bc26 Mon Sep 17 00:00:00 2001 From: Ian Abbott Date: Fri, 5 Jun 2015 18:30:08 +0100 Subject: [PATCH] staging: comedi: das08: improve test for programmable gain `das08_ai_rinsn()` handles Comedi `INSN_READ` instructions for the AI subdevice. This programs the gain for the analog input channel if the board has support for that, and acquires data from the channel. If programmable gain is supported, the gain code is read from the array pointed to by `devpriv->pg_gainlist` indexed by the range index. The function assumes that programmable gain is supported if the AI subdevice's range table supports more than one range. Replace that with a more direct test for `devpriv->pg_gainlist` being non-NULL, as it is only initialized to a non-NULL pointer for boards that support programmable gain. This will also allow range tables to be included for convenience for those boards that support multiple ranges by DIP switches. Those boards are currently initialized to use a single "unknown" range. Signed-off-by: Ian Abbott Reviewed-by: H Hartley Sweeten Signed-off-by: Greg Kroah-Hartman --- drivers/staging/comedi/drivers/das08.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/staging/comedi/drivers/das08.c b/drivers/staging/comedi/drivers/das08.c index b1cd6ea..2521352 100644 --- a/drivers/staging/comedi/drivers/das08.c +++ b/drivers/staging/comedi/drivers/das08.c @@ -225,7 +225,7 @@ static int das08_ai_rinsn(struct comedi_device *dev, struct comedi_subdevice *s, outb(devpriv->do_mux_bits, dev->iobase + DAS08_CONTROL); spin_unlock(&dev->spinlock); - if (s->range_table->length > 1) { + if (devpriv->pg_gainlist) { /* set gain/range */ range = CR_RANGE(insn->chanspec); outb(devpriv->pg_gainlist[range], -- 2.7.4