On 14/04/2021 13:34, Ian Abbott wrote:
On 14/04/2021 11:09, Dan Carpenter wrote:
The test_ni_get_reg_value() function calls
unittest(ni_get_reg_value_roffs(-1, O(0), T, 1) == -1,
"check bad direct trigger arg for first reg->dest w/offs\n");
The -1 is type promoted to a high positive value so src is greater than
NI_NAMES_BASE. It's not clear that that was intentional.
drivers/staging/comedi/drivers/tests/../ni_routes.h:269
ni_get_reg_value_roffs() warn: 'src' possible negative type promoted
to high
I agree that it appears that ni_get_reg_value_roffs() will be returning
-1 as expected, but for the wrong reason. I think the intention was for
ni_get_reg_value_roffs() to call route_register_is_valid() with src=0 in
this case, but it actually calls ni_route_to_register() with src=-1
(because -1 gets converted to 0xffffffff in the test `if (src <
NI_NAMES_BASE)` where NI_NAMES_BASE is defined as 0x8000u).
Since Spencer agrees that the existing behavior was unintentional, I
think the least disruptive fix would be change `src < NI_NAMES_BASE` to
`src < (int)NI_NAMES_BASE` in `ni_get_reg_value_roffs()` in
".../comedi/drivers/ni_routes.h".
Either that, or change the interface to use unsigned `src` and
`direct_reg_offset` values. The negative values only seem to be used by
the "ni_routes_test" unit testing module.
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