The 2nd parameter of 'find_first_zero_bit' is the number of bits to search. In this case, we are passing 'sizeof(vt8500_ports_in_use)'. 'vt8500_ports_in_use' is an 'unsigned long'. So the sizeof is likely to return 4. A few lines below, we check if it is below VT8500_MAX_PORTS, which is 6. It is likely that the number of bits in a long was expected here, so use BITS_PER_LONG instead. It has been spotted by the following coccinelle script: @@ expression ret, x; @@ * ret = \(find_first_bit \| find_first_zero_bit\) (x, sizeof(...)); Signed-off-by: Christophe JAILLET <christophe.jaillet@xxxxxxxxxx> --- Other options are possible: - 'vt8500_ports_in_use' being a 'unsigned long', use ffz to reduce code verbosity - VT8500_MAX_PORTS, in order to be consistent with the test below --- drivers/tty/serial/vt8500_serial.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/tty/serial/vt8500_serial.c b/drivers/tty/serial/vt8500_serial.c index 23cfc5e16b45..935076c50cb1 100644 --- a/drivers/tty/serial/vt8500_serial.c +++ b/drivers/tty/serial/vt8500_serial.c @@ -664,7 +664,7 @@ static int vt8500_serial_probe(struct platform_device *pdev) if (port < 0) { /* calculate the port id */ port = find_first_zero_bit(&vt8500_ports_in_use, - sizeof(vt8500_ports_in_use)); + BITS_PER_LONG); } if (port >= VT8500_MAX_PORTS) -- 2.7.4 --- L'absence de virus dans ce courrier électronique a été vérifiée par le logiciel antivirus Avast. https://www.avast.com/antivirus -- To unsubscribe from this list: send the line "unsubscribe linux-serial" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html