xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Input: fix open/close races in joystick drivers - add a semaphore

Browse Source 
to the ones that register more than one input device.

Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
This commit is contained in:
Dmitry Torokhov
2005-05-29 02:29:52 -05:00
parent af24604127
commit 8b1a198bf1
4 changed files with 61 additions and 23 deletions
Download Patch File Download Diff File Expand all files Collapse all files

29
drivers/input/joystick/amijoy.c
View File

@@ -51,7 +51,8 @@ MODULE_PARM_DESC(map, "Map of attached joysticks in form of <a>,<b> (default is
__obsolete_setup("amijoy=");
static int amijoy_used[2] = { 0, 0 };
static int amijoy_used;
static DECLARE_MUTEX(amijoy_sem);
static struct input_dev amijoy_dev[2];
static char *amijoy_phys[2] = { "amijoy/input0", "amijoy/input1" };
@@ -84,26 +85,30 @@ static irqreturn_t amijoy_interrupt(int irq, void *dummy, struct pt_regs *fp)
static int amijoy_open(struct input_dev *dev)
{
int *used = dev->private;
int err;
if ((*used)++)
return 0;
err = down_interruptible(&amijoy_sem);
if (err)
return err;
if (request_irq(IRQ_AMIGA_VERTB, amijoy_interrupt, 0, "amijoy", amijoy_interrupt)) {
(*used)--;
if (!amijoy_used && request_irq(IRQ_AMIGA_VERTB, amijoy_interrupt, 0, "amijoy", amijoy_interrupt)) {
printk(KERN_ERR "amijoy.c: Can't allocate irq %d\n", IRQ_AMIGA_VERTB);
return -EBUSY;
err = -EBUSY;
goto out;
}
return 0;
amijoy_used++;
out:
up(&amijoy_sem);
return err;
}
static void amijoy_close(struct input_dev *dev)
{
int *used = dev->private;
if (!--(*used))
down(&amijoysem);
if (!--amijoy_used)
free_irq(IRQ_AMIGA_VERTB, amijoy_interrupt);
up(&amijoy_sem);
}
static int __init amijoy_init(void)
@@ -138,8 +143,6 @@ static int __init amijoy_init(void)
amijoy_dev[i].id.product = 0x0003;
amijoy_dev[i].id.version = 0x0100;
amijoy_dev[i].private = amijoy_used + i;
input_register_device(amijoy_dev + i);
printk(KERN_INFO "input: %s at joy%ddat\n", amijoy_name, i);
}