Re: zr36120 2.6.x port (was: Re: [Mjpeg-users] DC30+ can't capture size greater than 224x168)

[Christoph Hellwig <hch@infradead.org>]

On Thu, Sep 25, 2003 at 05:59:44PM +0200, Ronald Bultje wrote:
> +	if (!try_module_get(THIS_MODULE)) {
> +		printk(KERN_ERR "failed to acquire lock on myself\n");
> +		return -EIO;
> +	}

This is broken, you need an owner outside the open routine.

> +
> +	/* find the device */
> +	for (i = 0; i < zoran_cards; i++) {
> +		if (zorans[i].video_dev->minor == minor) {
> +			ztv = &zorans[i];
> +			break;
> +		}
> +	}

What serializes this?

> +	if (ztv->have_decoder &&
> +	    !try_module_get(ztv->decoder->driver->owner)) {
> +		printk(KERN_ERR "Failed to acquire lock on TV decoder\n");
> +		module_put(THIS_MODULE);
> +		return -EIO;
> +	} 
> +	if (ztv->have_tuner &&
> +	    !try_module_get(ztv->tuner->driver->owner)) {
> +		printk(KERN_ERR "Failed to acquire lock on TV tuner\n");
> +		if (ztv->have_decoder)
> +			module_put(ztv->decoder->driver->owner);
> +		module_put(THIS_MODULE);
> +		return -EIO;
> +	}

You probably want to add a few gotos to unwind at the end of the
function with less code deuplication..