[PATCH 4/8] New set of input patches

Dmitry Torokhov
2004-07-08T07:02:06Z

===================================================================

ChangeSet@1.1823, 2004-07-08 00:24:20-05:00, dtor_core@ameritech.net
Input: add serio_pause_rx and serio_continue_rx so drivers can protect
their critical sections from port's interrupt handler

Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

drivers/input/serio/serio.c | 18 ++++++++----------
include/linux/serio.h | 21 +++++++++++++++++++--
2 files changed, 27 insertions(+), 12 deletions(-)

===================================================================

diff -Nru a/drivers/input/serio/serio.c b/drivers/input/serio/serio.c
--- a/drivers/input/serio/serio.c 2004-07-08 01:35:14 -05:00
+++ b/drivers/input/serio/serio.c 2004-07-08 01:35:14 -05:00
@@ -541,15 +541,14 @@
/* called from serio_driver->connect/disconnect methods under serio_sem */
int serio_open(struct serio *serio, struct serio_driver *drv)
{
- unsigned long flags;
-
- spin_lock_irqsave(&serio->lock, flags);
+ serio_pause_rx(serio);
serio->drv = drv;
- spin_unlock_irqrestore(&serio->lock, flags);
+ serio_continue_rx(serio);
+
if (serio->open && serio->open(serio)) {
- spin_lock_irqsave(&serio->lock, flags);
+ serio_pause_rx(serio);
serio->drv = NULL;
- spin_unlock_irqrestore(&serio->lock, flags);
+ serio_continue_rx(serio);
return -1;
}
return 0;
@@ -558,13 +557,12 @@
/* called from serio_driver->connect/disconnect methods under serio_sem */
void serio_close(struct serio *serio)
{
- unsigned long flags;
-
if (serio->close)
serio->close(serio);
- spin_lock_irqsave(&serio->lock, flags);
+
+ serio_pause_rx(serio);
serio->drv = NULL;
- spin_unlock_irqrestore(&serio->lock, flags);
+ serio_continue_rx(serio);
}

irqreturn_t serio_interrupt(struct serio *serio,
diff -Nru a/include/linux/serio.h b/include/linux/serio.h
--- a/include/linux/serio.h 2004-07-08 01:35:14 -05:00
+++ b/include/linux/serio.h 2004-07-08 01:35:14 -05:00
@@ -35,7 +35,7 @@
unsigned long type;
unsigned long event;

- spinlock_t lock;
+ spinlock_t lock; /* protects critical sections from port's interrupt handler */

int (*write)(struct serio *, unsigned char);
int (*open)(struct serio *);
@@ -43,7 +43,7 @@

struct serio *parent, *child;

- struct serio_driver *drv; /* Accessed from interrupt, writes must be protected by serio_lock */
+ struct serio_driver *drv; /* accessed from interrupt, must be protected by serio->lock */

struct device dev;

@@ -81,6 +81,7 @@
void serio_register_port_delayed(struct serio *serio);
void serio_unregister_port(struct serio *serio);
void serio_unregister_port_delayed(struct serio *serio);
+
void serio_register_driver(struct serio_driver *drv);
void serio_unregister_driver(struct serio_driver *drv);

@@ -103,6 +104,22 @@
if (serio->drv && serio->drv->cleanup)
serio->drv->cleanup(serio);
}
+
+
+/*
+ * Use the following fucntions to protect critical sections in
+ * driver code from port's interrupt handler
+ */
+static __inline__ void serio_pause_rx(struct serio *serio)
+{
+ spin_lock_irq(&serio->lock);
+}
+
+static __inline__ void serio_continue_rx(struct serio *serio)
+{
+ spin_unlock_irq(&serio->lock);
+}
+

#endif