[alsa-devel] snd_ctl compiler warnings

The code I am working with at present includes unremarkable lines such as:

snd_ctl_elem_value_t *line_in_vol; snd_ctl_elem_value_alloca(&line_in_vol);

Building this with a cross compiler for arm based on gcc 4.2.1 gives this warning for the 2nd line:

: warning: the address of 'line_in_vol' will always evaluate as 'true'

but an older compiler on the desktop does not show this. Would this warning be expected in these circumstances, or is the compiler being over zealous? Am I missing something or is there a straightforward way to avoid such warnings? (Code runs OK).

Thanks

Alan