On Friday, May 02, 2014 9:50 AM, Ian Abbott wrote:
> On 2014-05-02 15:57, Brilliantov Kirill Vladimirovich wrote:
>> Signed-off-by: Brilliantov Kirill Vladimirovich <brillian...@inbox.ru>
>> ---
>> drivers/staging/comedi/drivers/ni_stc.h | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/staging/comedi/drivers/ni_stc.h
>> b/drivers/staging/comedi/drivers/ni_stc.h
>> index f0630b78..197b568 100644
>> --- a/drivers/staging/comedi/drivers/ni_stc.h
>> +++ b/drivers/staging/comedi/drivers/ni_stc.h
>> @@ -717,7 +717,7 @@ enum AI_AO_Select_Bits {
>> static inline unsigned ni_stc_dma_channel_select_bitfield(unsigned channel)
>> {
>> if (channel < 4)
>> - return 1 << channel;
>> + return 1 << (channel & 0x3);
>> if (channel == 4)
>> return 0x3;
>> if (channel == 5)
>>
>
> The warning seems a bit spurious!
The whole mite.c driver and it's users are all a bit of a mess.
I did find the information about the "AI AO Select Register" in the National
Instruments PCI E Series manual:
-----
The AI AO Select Register contains 8 bits that control the logical DMA
selection for the
analog input and analog output resources. The contents of this register are
cleared upon power
up and after a reset condition.
Address: base address + 0x09
Type: write-only
Word size: 8-bit
Bit Name Description
7-4 Reserved Reserved-Always write 0 to these bits (for
PCI-6032E
and PCI-6033E only).
7-4 Output<D..A> Analog Output Logical Channel D through A-These
four
bits select the logical channels of the MITE to
be used by
the analog output. You can only set one of
these bits at a
time (except for the PCI-6032E and PCI-6033E).
3-0 Input<D..A> Analog Input Logical Channel D through A-These
four
bits select the logical channels to be used by
the analog
input. You can only set one of these bits at a
time.
-----
Based on this the ni_stc_dma_channel_select_bitfield() function appears to be
incorrect. The "channel"s should only be in the range 0 to 3 and result in a
returned
bitfield of:
channel bitfield Description
0 0x01 Analog Input or Output Channel A
1 0x02 Analog Input or Output Channel B
2 0x04 Analog Input or Output Channel C
3 0x08 Analog Input or Output Channel D
Just my two cents...
Hartley
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