Current kgdboc only configures the uart port in poll mode, which block
any gdb break signal Ctrl+C from taking effect till a tty on the port is
opened by an application. This patch introduces 2 hook functions in
struct tty_operations and uart_operations. The kgdboc port can be start
up without openning ttys after gdb is connected.
Signed-off-by: Sonic Zhang <sonic.adi@gmail.com>
---
drivers/serial/kgdboc.c | 8 +++++++-
drivers/serial/serial_core.c | 38 ++++++++++++++++++++++++++++++++++++++
include/linux/serial_core.h | 9 +++++++++
include/linux/tty_driver.h | 5 +++++
4 files changed, 59 insertions(+), 1 deletions(-)
diff --git a/drivers/serial/kgdboc.c b/drivers/serial/kgdboc.c
index eadc1ab..5d91f3d 100644
--- a/drivers/serial/kgdboc.c
+++ b/drivers/serial/kgdboc.c
@@ -70,6 +70,9 @@ static int configure_kgdboc(void)
configured = 1;
+ kgdb_tty_driver->ops->kgdboc_port_startup(kgdb_tty_driver,
+ kgdb_tty_line);
+
return 0;
noconfig:
@@ -90,8 +93,11 @@ static int __init init_kgdboc(void)
static void cleanup_kgdboc(void)
{
- if (configured == 1)
+ if (configured == 1) {
+ kgdb_tty_driver->ops->kgdboc_port_shutdown(kgdb_tty_driver,
+ kgdb_tty_line);
kgdb_unregister_io_module(&kgdboc_io_ops);
+ }
}
static int kgdboc_get_char(void)
diff --git a/drivers/serial/serial_core.c b/drivers/serial/serial_core.c
index 73e9b8f..07f1b04 100644
--- a/drivers/serial/serial_core.c
+++ b/drivers/serial/serial_core.c
@@ -2244,6 +2244,39 @@ uart_configure_port(struct uart_driver *drv, struct uart_state *state,
}
}
+#if defined(CONFIG_KGDB_SERIAL_CONSOLE) || \
+ defined(CONFIG_KGDB_SERIAL_CONSOLE_MODULE)
+static int uart_kgdboc_port_startup(struct tty_driver *driver, int line)
+{
+ struct uart_driver *drv = driver->driver_state;
+ struct uart_state *state = drv->state + line;
+ struct uart_port *port;
+
+ if (!state || !state->port)
+ return -1;
+
+ port = state->port;
+ if (port->ops->kgdboc_port_startup)
+ return port->ops->kgdboc_port_startup(port);
+ else
+ return -1;
+}
+
+static void uart_kgdboc_port_shutdown(struct tty_driver *driver, int line)
+{
+ struct uart_driver *drv = driver->driver_state;
+ struct uart_state *state = drv->state + line;
+ struct uart_port *port;
+
+ if (!state || !state->port)
+ return;
+
+ port = state->port;
+ if (port->ops->kgdboc_port_shutdown)
+ port->ops->kgdboc_port_shutdown(port);
+}
+#endif
+
#ifdef CONFIG_CONSOLE_POLL
static int uart_poll_init(struct tty_driver *driver, int line, char *options)
@@ -2323,6 +2356,11 @@ static const struct tty_operations uart_ops = {
#endif
.tiocmget = uart_tiocmget,
.tiocmset = uart_tiocmset,
+#if defined(CONFIG_KGDB_SERIAL_CONSOLE) || \
+ defined(CONFIG_KGDB_SERIAL_CONSOLE_MODULE)
+ .kgdboc_port_startup = uart_kgdboc_port_startup,
+ .kgdboc_port_shutdown = uart_kgdboc_port_shutdown,
+#endif
#ifdef CONFIG_CONSOLE_POLL
.poll_init = uart_poll_init,
.poll_get_char = uart_poll_get_char,
diff --git a/include/linux/serial_core.h b/include/linux/serial_core.h
index 3b2f6c0..4a15311 100644
--- a/include/linux/serial_core.h
+++ b/include/linux/serial_core.h
@@ -214,6 +214,15 @@ struct uart_ops {
void (*config_port)(struct uart_port *, int);
int (*verify_port)(struct uart_port *, struct serial_struct *);
int (*ioctl)(struct uart_port *, unsigned int, unsigned long);
+#if defined(CONFIG_KGDB_SERIAL_CONSOLE) || \
+ defined(CONFIG_KGDB_SERIAL_CONSOLE_MODULE)
+ /*
+ * Start up serial port earlier in kgdboc to support gdb break
+ * signal Ctrl+C.
+ */
+ int (*kgdboc_port_startup)(struct uart_port *);
+ void (*kgdboc_port_shutdown)(struct uart_port *);
+#endif
#ifdef CONFIG_CONSOLE_POLL
void (*poll_put_char)(struct uart_port *, unsigned char);
int (*poll_get_char)(struct uart_port *);
diff --git a/include/linux/tty_driver.h b/include/linux/tty_driver.h
index 16d2794..efd26cf 100644
--- a/include/linux/tty_driver.h
+++ b/include/linux/tty_driver.h
@@ -220,6 +220,11 @@ struct tty_operations {
unsigned int set, unsigned int clear);
int (*resize)(struct tty_struct *tty, struct tty_struct *real_tty,
struct winsize *ws);
+#if defined(CONFIG_KGDB_SERIAL_CONSOLE) || \
+ defined(CONFIG_KGDB_SERIAL_CONSOLE_MODULE)
+ int (*kgdboc_port_startup)(struct tty_driver *driver, int line);
+ int (*kgdboc_port_shutdown)(struct tty_driver *driver, int line);
+#endif
#ifdef CONFIG_CONSOLE_POLL
int (*poll_init)(struct tty_driver *driver, int line, char *options);
int (*poll_get_char)(struct tty_driver *driver, int line);
--
1.6.0
--
