> Without this patch Exar XR16C2852 UARTs are detected
> as Motorola 8xxx DUARTs (16550A compatible).
>
> By checking the fifo size it is possible to
> continue probing for the correct UART type.
>
> Signed-off-by: Matthias Fuchs <mfuchs@xxxxxxxx>
> ---
> drivers/serial/8250.c | 22 +++++++++++++++++++---
> 1 files changed, 19 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/serial/8250.c b/drivers/serial/8250.c
> index 303272a..ec27086 100644
> --- a/drivers/serial/8250.c
> +++ b/drivers/serial/8250.c
> @@ -782,7 +782,7 @@ static void autoconfig_has_efr(struct uart_8250_port *up)
> * reading back DLL and DLM. The chip type depends on the DLM
> * value read back:
> * 0x10 - XR16C850 and the DLL contains the chip revision.
> - * 0x12 - XR16C2850.
> + * 0x12 - XR16C2850 + XR16C2852.
> * 0x14 - XR16C854.
> */
> id1 = autoconfig_read_divisor_id(up);
> @@ -869,11 +869,27 @@ static void autoconfig_16550a(struct uart_8250_port *up)
> DEBUG_AUTOCONF("EFRv1 ");
> up->port.type = PORT_16650;
> up->capabilities |= UART_CAP_EFR | UART_CAP_SLEEP;
> + serial_outp(up, UART_EFR, 0);
> + return;
> } else {
> - DEBUG_AUTOCONF("Motorola 8xxx DUART ");
> + int sf = size_fifo(up);
> + DEBUG_AUTOCONF("sf=%d ", sf);
> + /*
> + * This fifo size check is needed to detect
> + * Exar XR16C2852 UARTs later on.
> + * These devices have an AFR register at
> + * UART_EFR's address with LCR_DLAB set.
> + * Because of thier 128 byte fifo we can
> + * skip this point of return and let
> + * autoconfig_has_efr() detect them later.
> + */
> + if (sf != 128) {
> + DEBUG_AUTOCONF("Motorola 8xxx DUART ");
> + serial_outp(up, UART_EFR, 0);
> + return;
> + }
> }
> serial_outp(up, UART_EFR, 0);
> - return;
> }
>
> /*
Did any body go over my above patch from December?
Matthias
--
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
