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[SERIAL] Fix oops when removing suspended serial port 

A serial card might have been removed when the system is resumed.
This results in a suspended port being shut down, which results in
the ports shutdown method being called twice in a row.  This causes
BUGs.  Avoid this by tracking the suspended state separately from
the initialised state.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This commit is contained in:
Russell King 2006-10-01 17:17:40 +01:00 committed by Russell King
parent fe59d5372a
commit a6b93a9085
2 changed files with 8 additions and 2 deletions
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9
drivers/serial/serial_core.c
View File

@ -1940,6 +1940,9 @@ int uart_suspend_port(struct uart_driver *drv, struct uart_port *port)
if (state->info && state->info->flags & UIF_INITIALIZED) { if (state->info && state->info->flags & UIF_INITIALIZED) {
const struct uart_ops *ops = port->ops; const struct uart_ops *ops = port->ops;
state->info->flags = (state->info->flags & ~UIF_INITIALIZED)
| UIF_SUSPENDED;
spin_lock_irq(&port->lock); spin_lock_irq(&port->lock);
ops->stop_tx(port); ops->stop_tx(port);
ops->set_mctrl(port, 0); ops->set_mctrl(port, 0);
@ -2006,7 +2009,7 @@ int uart_resume_port(struct uart_driver *drv, struct uart_port *port)
console_start(port->cons); console_start(port->cons);
} }
if (state->info && state->info->flags & UIF_INITIALIZED) { if (state->info && state->info->flags & UIF_SUSPENDED) {
const struct uart_ops *ops = port->ops; const struct uart_ops *ops = port->ops;
int ret; int ret;
@ -2018,15 +2021,17 @@ int uart_resume_port(struct uart_driver *drv, struct uart_port *port)
ops->set_mctrl(port, port->mctrl); ops->set_mctrl(port, port->mctrl);
ops->start_tx(port); ops->start_tx(port);
spin_unlock_irq(&port->lock); spin_unlock_irq(&port->lock);
state->info->flags |= UIF_INITIALIZED;
} else { } else {
/* /*
* Failed to resume - maybe hardware went away? * Failed to resume - maybe hardware went away?
* Clear the "initialized" flag so we won't try * Clear the "initialized" flag so we won't try
* to call the low level drivers shutdown method. * to call the low level drivers shutdown method.
*/ */
state->info->flags &= ~UIF_INITIALIZED;
uart_shutdown(state); uart_shutdown(state);
} }
state->info->flags &= ~UIF_SUSPENDED;
} }
mutex_unlock(&state->mutex); mutex_unlock(&state->mutex);

1
include/linux/serial_core.h
View File

@ -319,6 +319,7 @@ struct uart_info {
#define UIF_CTS_FLOW ((__force uif_t) (1 << 26)) #define UIF_CTS_FLOW ((__force uif_t) (1 << 26))
#define UIF_NORMAL_ACTIVE ((__force uif_t) (1 << 29)) #define UIF_NORMAL_ACTIVE ((__force uif_t) (1 << 29))
#define UIF_INITIALIZED ((__force uif_t) (1 << 31)) #define UIF_INITIALIZED ((__force uif_t) (1 << 31))
#define UIF_SUSPENDED ((__force uif_t) (1 << 30))
int blocked_open; int blocked_open;