Em 19-11-2010 21:43, David Härdeman escreveu:
> The use of the saa7134_card_ir->users seems racy, so protect the count with
> a spinlock. Also use proper data types as arguments to __saa7134_ir_start()
> and __saa7134_ir_stop() to remove some unnecessary casts.
Hmm... instead of using a spinlock, the better seems to use an atomic_t.
>
> Signed-off-by: David Härdeman <da...@hardeman.nu>
> ---
> drivers/media/video/saa7134/saa7134-input.c | 54
> ++++++++++++++++-----------
> drivers/media/video/saa7134/saa7134.h | 1 +
> 2 files changed, 33 insertions(+), 22 deletions(-)
>
> diff --git a/drivers/media/video/saa7134/saa7134-input.c
> b/drivers/media/video/saa7134/saa7134-input.c
> index 98678d9..8b80efb 100644
> --- a/drivers/media/video/saa7134/saa7134-input.c
> +++ b/drivers/media/video/saa7134/saa7134-input.c
> @@ -402,17 +402,12 @@ static void ir_raw_decode_timer_end(unsigned long data)
> ir->active = false;
> }
>
> -static int __saa7134_ir_start(void *priv)
> +static void __saa7134_ir_start(struct saa7134_dev *dev)
> {
> - struct saa7134_dev *dev = priv;
> - struct saa7134_card_ir *ir;
> -
> - if (!dev || !dev->remote)
> - return -EINVAL;
> + struct saa7134_card_ir *ir = dev->remote;
>
> - ir = dev->remote;
> if (ir->running)
> - return 0;
> + return;
>
> ir->running = true;
> ir->active = false;
> @@ -427,19 +422,12 @@ static int __saa7134_ir_start(void *priv)
> setup_timer(&ir->timer, ir_raw_decode_timer_end,
> (unsigned long)dev);
> }
> -
> - return 0;
> }
>
> -static void __saa7134_ir_stop(void *priv)
> +static void __saa7134_ir_stop(struct saa7134_dev *dev)
> {
> - struct saa7134_dev *dev = priv;
> - struct saa7134_card_ir *ir;
> -
> - if (!dev || !dev->remote)
> - return;
> + struct saa7134_card_ir *ir = dev->remote;
>
> - ir = dev->remote;
> if (!ir->running)
> return;
>
> @@ -448,39 +436,60 @@ static void __saa7134_ir_stop(void *priv)
>
> ir->active = false;
> ir->running = false;
> -
> - return;
> }
>
> int saa7134_ir_start(struct saa7134_dev *dev)
> {
> + if (!dev || !dev->remote)
> + return -EINVAL;
> +
> + spin_lock(&dev->remote->lock);
> if (dev->remote->users)
> - return __saa7134_ir_start(dev);
> + __saa7134_ir_start(dev);
> + spin_unlock(&dev->remote->lock);
>
> return 0;
> }
>
> void saa7134_ir_stop(struct saa7134_dev *dev)
> {
> + if (!dev || !dev->remote)
> + return;
> +
> + spin_lock(&dev->remote->lock);
> if (dev->remote->users)
> __saa7134_ir_stop(dev);
> + spin_unlock(&dev->remote->lock);
> }
>
> static int saa7134_ir_open(struct rc_dev *rc)
> {
> struct saa7134_dev *dev = rc->priv;
>
> + if (!dev || !dev->remote)
> + return -EINVAL;
> +
> + spin_lock(&dev->remote->lock);
> + if (dev->remote->users == 0)
> + __saa7134_ir_start(dev);
> dev->remote->users++;
> - return __saa7134_ir_start(dev);
> + spin_unlock(&dev->remote->lock);
> +
> + return 0;
> }
>
> static void saa7134_ir_close(struct rc_dev *rc)
> {
> struct saa7134_dev *dev = rc->priv;
>
> + if (!dev || !dev->remote)
> + return;
> +
> + spin_lock(&dev->remote->lock);
> dev->remote->users--;
> - if (!dev->remote->users)
> + if (dev->remote->users == 0)
> __saa7134_ir_stop(dev);
> + spin_unlock(&dev->remote->lock);
> }
>
> int saa7134_input_init1(struct saa7134_dev *dev)
> @@ -744,6 +753,7 @@ int saa7134_input_init1(struct saa7134_dev *dev)
> ir->mask_keyup = mask_keyup;
> ir->polling = polling;
> ir->raw_decode = raw_decode;
> + spin_lock_init(&ir->lock);
>
> /* init input device */
> snprintf(ir->name, sizeof(ir->name), "saa7134 IR (%s)",
> diff --git a/drivers/media/video/saa7134/saa7134.h
> b/drivers/media/video/saa7134/saa7134.h
> index babfbe7..7c836c3 100644
> --- a/drivers/media/video/saa7134/saa7134.h
> +++ b/drivers/media/video/saa7134/saa7134.h
> @@ -125,6 +125,7 @@ struct saa7134_card_ir {
> char name[32];
> char phys[32];
> unsigned users;
> + spinlock_t lock;
>
> u32 polling;
> u32 last_gpio;
>
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