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 <abbo...@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;
}
--
2.1.1
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