From: Corey Minyard <minyard@acm.org>
To: Linux Kernel <linux-kernel@vger.kernel.org>,
Russell King <rmk+lkml@arm.linux.org.uk>
Cc: linux-serial@vger.kernel.org
Date: Mon, 30 Apr 2007 17:06:40 -0500 [thread overview]
raw)
I think I've spotted a bug in the 8250 code, but I'm not really
sure. I'm having a hard time understanding why the lsr_break_flag
is necessary.
Subject: Serial 8250: clear the lsr_break_flag at open
The lsr_break_flag in the 8250 driver is not cleared when the port is
opened. This means that on a serial console, if a break has occurred
while the port is closed, the first call to receive_chars() will
result in a break being delivered at that point. Clear the flag at
open to fix the problem.
Signed-off-by: Corey Minyard <minyard@acm.org>
Index: linux-2.6.21/drivers/serial/8250.c
===================================================================
--- linux-2.6.21.orig/drivers/serial/8250.c
+++ linux-2.6.21/drivers/serial/8250.c
@@ -1638,6 +1638,7 @@ static int serial8250_startup(struct uar
up->capabilities = uart_config[up->port.type].flags;
up->mcr = 0;
+ up->lsr_break_flag = 0;
if (up->port.type == PORT_16C950) {
/* Wake up and initialize UART */
WARNING: multiple messages have this Message-ID (diff)
From: Corey Minyard <minyard@acm.org>
To: Linux Kernel <linux-kernel@vger.kernel.org>,
Russell King <rmk+lkml@arm.linux.org.uk>
Cc: linux-serial@vger.kernel.org
Subject: (unknown)
Date: Mon, 30 Apr 2007 17:06:40 -0500 [thread overview]
Message-ID: <20070430220640.GA26410@localdomain> (raw)
I think I've spotted a bug in the 8250 code, but I'm not really
sure. I'm having a hard time understanding why the lsr_break_flag
is necessary.
Subject: Serial 8250: clear the lsr_break_flag at open
The lsr_break_flag in the 8250 driver is not cleared when the port is
opened. This means that on a serial console, if a break has occurred
while the port is closed, the first call to receive_chars() will
result in a break being delivered at that point. Clear the flag at
open to fix the problem.
Signed-off-by: Corey Minyard <minyard@acm.org>
Index: linux-2.6.21/drivers/serial/8250.c
===================================================================
--- linux-2.6.21.orig/drivers/serial/8250.c
+++ linux-2.6.21/drivers/serial/8250.c
@@ -1638,6 +1638,7 @@ static int serial8250_startup(struct uar
up->capabilities = uart_config[up->port.type].flags;
up->mcr = 0;
+ up->lsr_break_flag = 0;
if (up->port.type == PORT_16C950) {
/* Wake up and initialize UART */
next reply other threads:[~2007-04-30 22:06 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-04-30 22:06 Corey Minyard [this message]
2007-04-30 22:06 ` (unknown) Corey Minyard
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