From d41a4b515e346b3afdb5147d86927fa5835fc13b Mon Sep 17 00:00:00 2001 From: Chuck Ebbert Date: Thu, 1 Oct 2009 15:44:26 -0700 Subject: [PATCH] serial: add parameter to force skipping the test for the TXEN bug Allow users to force skipping the TXEN test at init time. Applies to all serial ports. Intended for debugging only. There is a blacklist for devices where we need to skip the test but the list is not complete. This lets users force skipping the test so we can determine if they need to be added to the list. Some HP machines with weird serial consoles have this problem and there may be more. Signed-off-by: Chuck Ebbert Cc: Alan Cox Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/serial/8250.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/drivers/serial/8250.c b/drivers/serial/8250.c index 2209620d2349..b1ae774016f1 100644 --- a/drivers/serial/8250.c +++ b/drivers/serial/8250.c @@ -64,6 +64,8 @@ static int serial_index(struct uart_port *port) return (serial8250_reg.minor - 64) + port->line; } +static unsigned int skip_txen_test; /* force skip of txen test at init time */ + /* * Debugging. */ @@ -2108,7 +2110,7 @@ static int serial8250_startup(struct uart_port *port) is variable. So, let's just don't test if we receive TX irq. This way, we'll never enable UART_BUG_TXEN. */ - if (up->port.flags & UPF_NO_TXEN_TEST) + if (skip_txen_test || up->port.flags & UPF_NO_TXEN_TEST) goto dont_test_tx_en; /* @@ -3248,6 +3250,9 @@ MODULE_PARM_DESC(share_irqs, "Share IRQs with other non-8250/16x50 devices" module_param(nr_uarts, uint, 0644); MODULE_PARM_DESC(nr_uarts, "Maximum number of UARTs supported. (1-" __MODULE_STRING(CONFIG_SERIAL_8250_NR_UARTS) ")"); +module_param(skip_txen_test, uint, 0644); +MODULE_PARM_DESC(skip_txen_test, "Skip checking for the TXEN bug at init time"); + #ifdef CONFIG_SERIAL_8250_RSA module_param_array(probe_rsa, ulong, &probe_rsa_count, 0444); MODULE_PARM_DESC(probe_rsa, "Probe I/O ports for RSA");