If fifo size is already set via uart_params, do not force it to 16 - which
may not match the actual hardware. Specifically Exar cards have fifo of
256 bytes.
Signed-off-by: Marek Marczykowski-Górecki <marma...@invisiblethingslab.com>
Reviewed-by: Jan Beulich <jbeul...@suse.com>
---
xen/drivers/char/ns16550.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/xen/drivers/char/ns16550.c b/xen/drivers/char/ns16550.c
index 16a73d0c0e47..97b85b0225cc 100644
--- a/xen/drivers/char/ns16550.c
+++ b/xen/drivers/char/ns16550.c
@@ -357,7 +357,8 @@ static void __init ns16550_init_preirq(struct serial_port
*port)
ns16550_setup_preirq(uart);
/* Check this really is a 16550+. Otherwise we have no FIFOs. */
- if ( ((ns_read_reg(uart, UART_IIR) & 0xc0) == 0xc0) &&
+ if ( uart->fifo_size <= 1 &&
+ ((ns_read_reg(uart, UART_IIR) & 0xc0) == 0xc0) &&
((ns_read_reg(uart, UART_FCR) & UART_FCR_TRG14) == UART_FCR_TRG14) )
uart->fifo_size = 16;
}
--
2.31.1
