staging: comedi: icp_multi: correct insn_bits returned data for DO

For some unfathomable reason, the Comedi `insn_bits` handler for the
digital output subdevice (`icp_multi_insn_bits_do()`) writes the digital
output register and reads back the unrelated digital input register.
Read back the current state of the outputs (held in `s->state`) instead.

Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Reviewed-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/staging/comedi/drivers/icp_multi.c b/drivers/staging/comedi/drivers/icp_multi.c
index a412394..fbbcab2 100644 (file)
--- a/drivers/staging/comedi/drivers/icp_multi.c
+++ b/drivers/staging/comedi/drivers/icp_multi.c
@@ -53,7 +53,7 @@ Configuration options: not applicable, uses PCI auto config
 #define ICP_MULTI_AI           2       /* R:   Analogue input data */
 #define ICP_MULTI_DAC_CSR      4       /* R/W: DAC command/status register */
 #define ICP_MULTI_AO           6       /* R/W: Analogue output data */
-#define ICP_MULTI_DI           8       /* R/W: Digital inouts */
+#define ICP_MULTI_DI           8       /* R/W: Digital inputs */
 #define ICP_MULTI_DO           0x0A    /* R/W: Digital outputs */
 #define ICP_MULTI_INT_EN       0x0C    /* R/W: Interrupt enable register */
 #define ICP_MULTI_INT_STAT     0x0E    /* R/W: Interrupt status register */
@@ -319,7 +319,7 @@ static int icp_multi_insn_bits_do(struct comedi_device *dev,
        if (comedi_dio_update_state(s, data))
                writew(s->state, dev->mmio + ICP_MULTI_DO);
 
-       data[1] = readw(dev->mmio + ICP_MULTI_DI);
+       data[1] = s->state;
 
        return insn->n;
 }