Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
Input: db9 - use guard notation when acquiring mutex
Using guard notation makes the code more compact and error handling
more robust by ensuring that mutexes are released in all code paths
when control leaves critical section.
Link: https://lore.kernel.org/r/20240904043104.1030257-2-dmitry.torokhov@gmail.com
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
+14
-16
+14
-16
drivers/input/joystick/db9.c
+14
-16
drivers/input/joystick/db9.c
···
505
505
{
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506
struct db9 *db9 = input_get_drvdata(dev);
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struct parport *port = db9->pd->port;
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-
int err;
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-
err = mutex_lock_interruptible(&db9->mutex);
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-
if (err)
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-
return err;
513
-
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-
if (!db9->used++) {
515
-
parport_claim(db9->pd);
516
-
parport_write_data(port, 0xff);
517
-
if (db9_modes[db9->mode].reverse) {
518
-
parport_data_reverse(port);
519
-
parport_write_control(port, DB9_NORMAL);
509
+
scoped_guard(mutex_intr, &db9->mutex) {
510
+
if (!db9->used++) {
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+
parport_claim(db9->pd);
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+
parport_write_data(port, 0xff);
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+
if (db9_modes[db9->mode].reverse) {
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+
parport_data_reverse(port);
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+
parport_write_control(port, DB9_NORMAL);
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+
}
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+
mod_timer(&db9->timer, jiffies + DB9_REFRESH_TIME);
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}
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-
mod_timer(&db9->timer, jiffies + DB9_REFRESH_TIME);
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+
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+
return 0;
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}
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-
mutex_unlock(&db9->mutex);
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-
return 0;
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+
return -EINTR;
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}
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525
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static void db9_close(struct input_dev *dev)
···
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struct db9 *db9 = input_get_drvdata(dev);
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struct parport *port = db9->pd->port;
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531
-
mutex_lock(&db9->mutex);
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+
guard(mutex)(&db9->mutex);
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+
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if (!--db9->used) {
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del_timer_sync(&db9->timer);
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parport_write_control(port, 0x00);
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parport_data_forward(port);
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parport_release(db9->pd);
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540
}
538
-
mutex_unlock(&db9->mutex);
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541
}
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static void db9_attach(struct parport *pp)