c99 inline semantics with gcc (mspgcc)

Question

I am writing a couple of functions that I would like to inline.

Reading here and using the second c99 inline option with inline on all declarations and definitions, like

Answer 1

To ensure that a function ACTUALLY can be inlined, it pretty much has to be defined in the header-file.

When you don't do that, most compilers won't actually inline the function.

So my suggestion would be to move the actual function content into the header file:

inline void SPFD54124B_write_cmd(uint16_t command)
{
    spi_write(command, CMD_WIDTH);
}