Subject: Re: [RFC][BNX2X]: New driver for Broadcom 10Gb Ethernet.

From: Jeff Garzik <[email-masked]>
Date: Tue, 07 Aug 2007 18:15:47 -0400

Michael Buesch wrote:
> On Wednesday 01 August 2007 10:31:17 Michael Chan wrote:
>> +static irqreturn_t bnx2x_msix_sp_int(int irq, void *dev_instance)
>> +{
>> +	struct net_device *dev = dev_instance;
> 
> You need to check if dev==NULL and bail out.
> Another driver sharing the IRQ with this might choose to pass the dev
> pointer as NULL.

NAK that advice:  It is pointless having such a check in the hottest of 
driver hot paths, since a large majority of drivers do not have such a 
check.

It is better to fix the extremely rare oddball that passes NULL to 
request_irq(), than to update all drivers to be slower due to the oddballs.

>> +	struct bnx2x *bp = netdev_priv(dev);
> 
> No check if the device actually _did_ generate the IRQ? Sharing...

Not for MSI

>> +static irqreturn_t bnx2x_msix_fp_int(int irq, void *fp_cookie)
>> +{
>> +
>> +	struct bnx2x_fastpath *fp = fp_cookie;
> 
> Check if fp==NULL

NAK

>> +	struct bnx2x *bp = fp->bp;
>> +	struct net_device *dev = bp->dev;
> 
> No share protection either?

MSI

>> +static irqreturn_t bnx2x_interrupt(int irq, void *dev_instance)
>> +{
>> +	struct net_device *dev = dev_instance;
> 
> Check if dev==NULL

NAK

>> +	struct bnx2x *bp = netdev_priv(dev);
>> +	u16 status = bnx2x_ack_int(bp);
>> +
>> +	if (unlikely(status == 0)) {
> 
> That's not unlikely.

in this case, agreed

the other comments seem fairly sane, and indeed should be considered for 
the existing drivers as well.

	Jeff