Hi, On Thu, Feb 28, 2013 at 12:42:06PM +0100, Gregory CLEMENT wrote: > >> Would you agree with this kind of patch to fix the issue? > >> > >> diff --git a/drivers/tty/serial/8250/8250.c b/drivers/tty/serial/8250/8250.c > >> index e2ac25a..0b284c6 100644 > >> --- a/drivers/tty/serial/8250/8250.c > >> +++ b/drivers/tty/serial/8250/8250.c > >> @@ -1119,7 +1119,7 @@ static void autoconfig(struct uart_8250_port *up, unsigned int probeflags) > >> serial_out(up, UART_LCR, 0); > >> > >> serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO); > >> - scratch = serial_in(up, UART_IIR) >> 6; > >> + scratch = (serial_in(up, UART_IIR) & 0xFF) >> 6; > >> > >> switch (scratch) { > >> case 0: > > > > Instead, can you test if it's enough for you to set the reg-io-width > > to 1 instead of 4: > > Yes indeed it worked and it seems to be the correct description of my > hardware. So I will fix the dtsi file. > > However isn't buggy to use a function as it returned a char whereas > it returns an int? Yes, the driver should probable be cleaned. It seems to be happening in quite a few places in 8250.c. autoconfig_16550a() has pretty much identical code in it, where UART_IIR is read to unsigned char and shifted without a mask. Br, -- heikki -- 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