[PATCH] staging: comedi: icp_multi: correct insn_bits returned data for DO

[Hartley Sweeten]

On Friday, October 31, 2014 7:32 AM, Ian Abbott wrote:
> 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 at mev.co.uk>
> ---
>  drivers/staging/comedi/drivers/icp_multi.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/staging/comedi/drivers/icp_multi.c b/drivers/staging/comedi/drivers/icp_multi.c
> index f4e1c1c..db744c8 100644
> --- 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;
>  }

Reviewed-by: H Hartley Sweeten <hsweeten at visionengravers.com>