Subject: Re: [PATCH 1/2] [RFC] NET: Implement a standard ndev_printk family

From: "Kok, Auke" <[email-masked]>
Date: Fri, 08 Jun 2007 16:42:31 -0700

Stephen Hemminger wrote:
>>  
>> +#define ndev_printk(kern_level, netif_level, netdev, format, arg...) \
>> +	do { if ((netdev)->msg_enable & NETIF_MSG_##netif_level) { \
>> +		printk(kern_level "%s: " format, \
>> +		(netdev)->name, ## arg); } } while (0)
> 
> Could you make a version that doesn't evaluate the arguments twice?

hmm you lost me there a bit; Do you want me to duplicate this code for all the 
ndev_err/ndev_info functions instead so that ndev_err doesn't direct back to 
ndev_printk?

>> +#ifdef DEBUG
>> +#define ndev_dbg(level, netdev, format, arg...) \
>> +	ndev_printk(KERN_DEBUG, level, netdev, format, ## arg)
>> +#else
>> +#define ndev_dbg(level, netdev, format, arg...) \
>> +	do { (void)(netdev); } while (0)
>> +#endif
>> +
>> +#define ndev_err(level, netdev, format, arg...) \
>> +	ndev_printk(KERN_ERR, level, netdev, format, ## arg)
>> +#define ndev_info(level, netdev, format, arg...) \
>> +	ndev_printk(KERN_INFO, level, netdev, format, ## arg)
>> +#define ndev_warn(level, netdev, format, arg...) \
>> +	ndev_printk(KERN_WARNING, level, netdev, format, ## arg)
>> +#define ndev_notice(level, netdev, format, arg...) \
>> +	ndev_printk(KERN_NOTICE, level, netdev, format, ## arg)
>> +
>>  #define netif_msg_drv(p)	((p)->msg_enable & NETIF_MSG_DRV)
>>  #define netif_msg_probe(p)	((p)->msg_enable & NETIF_MSG_PROBE)
>>  #define netif_msg_link(p)	((p)->msg_enable & NETIF_MSG_LINK)
>> diff --git a/net/core/dev.c b/net/core/dev.c
>> index 5a7f20f..e854c09 100644
>> --- a/net/core/dev.c
>> +++ b/net/core/dev.c
>> @@ -3376,6 +3376,16 @@ struct net_device *alloc_netdev(int sizeof_priv, const char *name,
>>  		dev->priv = netdev_priv(dev);
>>  
>>  	dev->get_stats = internal_stats;
>> +	dev->msg_enable = NETIF_MSG_DRV | NETIF_MSG_PROBE | NETIF_MSG_LINK;
>> +#ifdef DEBUG
>> +	/* put these to good use: */
>> +	dev->msg_enable |= NETIF_MSG_TIMER | NETIF_MSG_IFDOWN |
>> +	                   NETIF_MSG_IFUP | NETIF_MSG_RX_ERR |
>> +	                   NETIF_MSG_TX_ERR | NETIF_MSG_TX_QUEUED |
>> +	                   NETIF_MSG_INTR | NETIF_MSG_TX_DONE |
>> +	                   NETIF_MSG_RX_STATUS | NETIF_MSG_PKTDATA |
>> +	                   NETIF_MSG_HW | NETIF_MSG_WOL;
>> +#endif
> 
> Let driver writer choose message enable bits please.

the driver can, since these bits are set in alloc_netdev, nothing prevents a 
driver from setting the mask immediately afterwards. Putting in a sane default 
seems a good idea and good practice.

Maybe I went a bit far by going all out on the DEBUG flags tho... perhaps those 
can be removed or only NETIF_MSG_RX_ERR and NETIF_MSG_TX_ERR set with DEBUG.

Auke