From: Jean Delvare <[email protected]> Subject: 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. This fixes kernel.org bug #12802. Signed-off-by: Jean Delvare <[email protected]> --- linux/drivers/media/video/cx88/cx88-input.c | 25 ++++++++++++++++++++----- 1 file changed, 20 insertions(+), 5 deletions(-) --- v4l-dvb.orig/linux/drivers/media/video/cx88/cx88-input.c 2009-03-04 09:52:20.000000000 +0100 +++ v4l-dvb/linux/drivers/media/video/cx88/cx88-input.c 2009-03-04 19:03:17.000000000 +0100 @@ -49,8 +49,12 @@ struct cx88_IR { /* poll external decoder */ int polling; +#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,20) struct work_struct work; struct timer_list timer; +#else + struct delayed_work work; +#endif u32 gpio_addr; u32 last_gpio; u32 mask_keycode; @@ -144,6 +148,7 @@ static void cx88_ir_handle_key(struct cx } } +#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,20) static void ir_timer(unsigned long data) { struct cx88_IR *ir = (struct cx88_IR *)data; @@ -151,7 +156,6 @@ static void ir_timer(unsigned long data) schedule_work(&ir->work); } -#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,20) static void cx88_ir_work(void *data) #else static void cx88_ir_work(struct work_struct *work) @@ -160,23 +164,30 @@ static void cx88_ir_work(struct work_str #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,20) struct cx88_IR *ir = data; #else - struct cx88_IR *ir = container_of(work, struct cx88_IR, work); + struct delayed_work *dwork = container_of(work, struct delayed_work, + work); + struct cx88_IR *ir = container_of(dwork, struct cx88_IR, work); #endif cx88_ir_handle_key(ir); +#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,20) mod_timer(&ir->timer, jiffies + msecs_to_jiffies(ir->polling)); +#else + schedule_delayed_work(dwork, msecs_to_jiffies(ir->polling)); +#endif } void cx88_ir_start(struct cx88_core *core, struct cx88_IR *ir) { if (ir->polling) { - setup_timer(&ir->timer, ir_timer, (unsigned long)ir); #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,20) + setup_timer(&ir->timer, ir_timer, (unsigned long)ir); INIT_WORK(&ir->work, cx88_ir_work, ir); + schedule_work(&ir->work); #else - INIT_WORK(&ir->work, cx88_ir_work); + INIT_DELAYED_WORK(&ir->work, cx88_ir_work); + schedule_delayed_work(&ir->work, msecs_to_jiffies(ir->polling)); #endif - schedule_work(&ir->work); } if (ir->sampling) { core->pci_irqmask |= PCI_INT_IR_SMPINT; @@ -193,8 +204,12 @@ void cx88_ir_stop(struct cx88_core *core } if (ir->polling) { +#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,20) del_timer_sync(&ir->timer); flush_scheduled_work(); +#else + cancel_delayed_work_sync(&ir->work); +#endif } } -- Jean Delvare -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
