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

drivers/media/video/cx88/cx88-input.c

+7 −18
Original line number Diff line number Diff line
@@ -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);

}



/* ---------------------------------------------------------------------- */