2014-10-31 14:32:50

by Ian Abbott

Subject: [PATCH] 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 <[email protected]>
---
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;
}
--
2.1.1

2014-10-31 16:55:20

by Hartley Sweeten

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

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 <[email protected]>
> ---
> 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 <[email protected]>