Re: [PATCH 1/3] Improve type handling in interrupt handlers

[Jeff Garzik <jgarzik@pobox.com>]

Rusty Russell wrote:
> This improves typechecking of interrupt handlers by removing
> unnecessary (void *) casts and storing handlers in correctly-typed
> variables.
> 
> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
> Cc: Jeff Garzik <jgarzik@pobox.com>
> Cc: Ash Willis <ashwillis@programmer.net>
> Cc: linux-pcmcia@lists.infradead.org

FWIW, I have been working in this area extensively.

Check out the 'irq-cleanups' and 'irq-remove' branches of
git://git.kernel.org/pub/scm/linux/kernel/git/jgarzik/misc-2.6.git

(irq-remove is built on top of irq-cleanups)


> diff -r 0fe1a980708b drivers/net/eth16i.c
> --- a/drivers/net/eth16i.c	Thu Jan 17 14:48:56 2008 +1100
> +++ b/drivers/net/eth16i.c	Thu Jan 17 15:42:00 2008 +1100
> @@ -529,7 +529,7 @@ static int __init eth16i_probe1(struct n
>  
>  	/* Try to obtain interrupt vector */
>  
> -	if ((retval = request_irq(dev->irq, (void *)&eth16i_interrupt, 0, cardname, dev))) {
> +	if ((retval = request_irq(dev->irq, eth16i_interrupt, 0, cardname, dev))) {
>  		printk(KERN_WARNING "%s at %#3x, but is unusable due to conflicting IRQ %d.\n",
>  		       cardname, ioaddr, dev->irq);
>  		goto out;
> diff -r 0fe1a980708b drivers/net/ewrk3.c
> --- a/drivers/net/ewrk3.c	Thu Jan 17 14:48:56 2008 +1100
> +++ b/drivers/net/ewrk3.c	Thu Jan 17 15:42:00 2008 +1100
> @@ -635,7 +635,7 @@ static int ewrk3_open(struct net_device 
>  	STOP_EWRK3;
>  
>  	if (!lp->hard_strapped) {
> -		if (request_irq(dev->irq, (void *) ewrk3_interrupt, 0, "ewrk3", dev)) {
> +		if (request_irq(dev->irq, ewrk3_interrupt, 0, "ewrk3", dev)) {
>  			printk("ewrk3_open(): Requested IRQ%d is busy\n", dev->irq);
>  			status = -EAGAIN;
>  		} else {
> diff -r 0fe1a980708b drivers/net/skfp/skfddi.c
> --- a/drivers/net/skfp/skfddi.c	Thu Jan 17 14:48:56 2008 +1100
> +++ b/drivers/net/skfp/skfddi.c	Thu Jan 17 15:42:00 2008 +1100
> @@ -495,7 +495,7 @@ static int skfp_open(struct net_device *
>  
>  	PRINTK(KERN_INFO "entering skfp_open\n");
>  	/* Register IRQ - support shared interrupts by passing device ptr */
> -	err = request_irq(dev->irq, (void *) skfp_interrupt, IRQF_SHARED,
> +	err = request_irq(dev->irq, skfp_interrupt, IRQF_SHARED,
>  			  dev->name, dev);
>  	if (err)
>  		return err;

ACK all of the above


> diff -r 0fe1a980708b include/pcmcia/cs.h
> --- a/include/pcmcia/cs.h	Thu Jan 17 14:48:56 2008 +1100
> +++ b/include/pcmcia/cs.h	Thu Jan 17 15:42:01 2008 +1100
> @@ -170,7 +170,7 @@ typedef struct irq_req_t {
>      u_int	Attributes;
>      u_int	AssignedIRQ;
>      u_int	IRQInfo1, IRQInfo2; /* IRQInfo2 is ignored */
> -    void	*Handler;
> +    int		(*Handler)(int, void *);
>      void	*Instance;
>  } irq_req_t;
>  
> diff -r 0fe1a980708b sound/pci/als300.c
> --- a/sound/pci/als300.c	Thu Jan 17 14:48:56 2008 +1100
> +++ b/sound/pci/als300.c	Thu Jan 17 15:42:01 2008 +1100
> @@ -678,7 +678,7 @@ static int __devinit snd_als300_create(s
>  				       struct snd_als300 **rchip)
>  {
>  	struct snd_als300 *chip;
> -	void *irq_handler;
> +	int (*irq_handler)(int, void *);
>  	int err;
>  
>  	static struct snd_device_ops ops = {
> diff -r 0fe1a980708b drivers/net/e1000e/netdev.c
> --- a/drivers/net/e1000e/netdev.c	Thu Jan 17 14:48:56 2008 +1100
> +++ b/drivers/net/e1000e/netdev.c	Thu Jan 17 15:42:00 2008 +1100
> @@ -935,7 +935,7 @@ static int e1000_request_irq(struct e100
>  static int e1000_request_irq(struct e1000_adapter *adapter)
>  {
>  	struct net_device *netdev = adapter->netdev;
> -	void (*handler) = &e1000_intr;
> +	int (*handler)(int, void *) = &e1000_intr;
>  	int irq_flags = IRQF_SHARED;
>  	int err;
>  
> diff -r 0fe1a980708b drivers/net/e1000/e1000_main.c
> --- a/drivers/net/e1000/e1000_main.c	Thu Jan 17 14:48:56 2008 +1100
> +++ b/drivers/net/e1000/e1000_main.c	Thu Jan 17 15:42:00 2008 +1100
> @@ -299,7 +299,7 @@ static int e1000_request_irq(struct e100
>  static int e1000_request_irq(struct e1000_adapter *adapter)
>  {
>  	struct net_device *netdev = adapter->netdev;
> -	void (*handler) = &e1000_intr;
> +	irqreturn_t (*handler)(int, void *) = &e1000_intr;
>  	int irq_flags = IRQF_SHARED;
>  	int err;

NAK the rest.

You should be using irq_handler_t for all these.

(Coincedentally, doing so makes it easier for me to later on remove the 
almost-never-used 'irq' argument from all irq handlers)

	Jeff