On 5/20/22 07:32, Geert Uytterhoeven wrote:
The macros implementing Atari ROM port I/O writes do not cast away their output, unlike similar implementations for other I/O buses. When they are combined using conditional expressions in the definitions of outb() and friends, this triggers sparse warnings like: drivers/net/appletalk/cops.c:382:17: error: incompatible types in conditional expression (different base types): drivers/net/appletalk/cops.c:382:17: unsigned char drivers/net/appletalk/cops.c:382:17: void Fix this by adding casts to "void". Reported-by: kernel test robot <lkp@xxxxxxxxx> Reported-by: Guenter Roeck <linux@xxxxxxxxxxxx> Signed-off-by: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>
Reviewed-by: Guenter Roeck <linux@xxxxxxxxxxxx>
--- Survived m68k/allmodconfig. To be queued in the m68k tree for v5.19. Removing the casts instead causes issues with functions propagating void return values (return expression in void function), which BTW sparse complains about, too.
We live and learn. I didn't even know that this was valid syntax. I thought it might be easier to just fix that code, but coccinelle reports that there are hundreds of places in the kernel where this is done. Outch. Guenter