Commit 569b7ec7 authored by Jean Delvare's avatar Jean Delvare Committed by Mauro Carvalho Chehab

V4L/DVB (10943): cx88: Prevent general protection fault on rmmod

When unloading the cx8800 driver I sometimes get a general protection
fault. Analysis revealed a race in cx88_ir_stop(). It can be solved by
using a delayed work instead of a timer for infrared input polling.
Signed-off-by: default avatarJean Delvare <khali@linux-fr.org>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@redhat.com>
parent fb6991d4
......@@ -48,8 +48,7 @@ struct cx88_IR {
/* poll external decoder */
int polling;
struct work_struct work;
struct timer_list timer;
struct delayed_work work;
u32 gpio_addr;
u32 last_gpio;
u32 mask_keycode;
......@@ -143,27 +142,19 @@ static void cx88_ir_handle_key(struct cx88_IR *ir)
}
}
static void ir_timer(unsigned long data)
{
struct cx88_IR *ir = (struct cx88_IR *)data;
schedule_work(&ir->work);
}
static void cx88_ir_work(struct work_struct *work)
{
struct cx88_IR *ir = container_of(work, struct cx88_IR, work);
struct cx88_IR *ir = container_of(work, struct cx88_IR, work.work);
cx88_ir_handle_key(ir);
mod_timer(&ir->timer, jiffies + msecs_to_jiffies(ir->polling));
schedule_delayed_work(&ir->work, msecs_to_jiffies(ir->polling));
}
void cx88_ir_start(struct cx88_core *core, struct cx88_IR *ir)
{
if (ir->polling) {
setup_timer(&ir->timer, ir_timer, (unsigned long)ir);
INIT_WORK(&ir->work, cx88_ir_work);
schedule_work(&ir->work);
INIT_DELAYED_WORK(&ir->work, cx88_ir_work);
schedule_delayed_work(&ir->work, 0);
}
if (ir->sampling) {
core->pci_irqmask |= PCI_INT_IR_SMPINT;
......@@ -179,10 +170,8 @@ void cx88_ir_stop(struct cx88_core *core, struct cx88_IR *ir)
core->pci_irqmask &= ~PCI_INT_IR_SMPINT;
}
if (ir->polling) {
del_timer_sync(&ir->timer);
flush_scheduled_work();
}
if (ir->polling)
cancel_delayed_work_sync(&ir->work);
}
/* ---------------------------------------------------------------------- */
......
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