The enclosed patch implements the netdev_* error-logging macros for
network drivers.  These macros have been discussed at length on the
linux-kernel and linux-netdev lists.  With the v2.6.0-test6 version of
these macros, we addressed all the issues that reviewers had raised.
This is just an update for v2.6.0-test11.

As previously discussed, these macros are in demand now (e.g., for
the e1000 driver) and have essentially no impact on drivers that
don't use them.

RECAP (from previous posts):
Calls to the netdev_* macros (netdev_printk and wrappers such as
netdev_err) are intended to replace calls to printk in network device
drivers.  These macros have the following characteristics:
- Same format + args as the corresponding printk call.
- Approximately the same amount of text as the corresponding printk call.
- The first arg is a pointer to the net_device struct.
- The second arg, which is a NETIF_MSG_* message level, can be used to
implement verbosity control.
- Standard message prefixes: verbose (interface name, driver name, bus ID)
during probe, or just the interface name once the device is registered.
- The current implementation just calls printk.  However, the netdev_*
interface (and availability of the net_device pointer) opens the door
for logging additional information (via printk, via evlog/netlink, etc.)
as desired, with no change to driver code.

Examples:
        netdev_err(netdev, RX_ERR, "No mem: dropped packet\n");
logs a message such as the following if the NETIF_MSG_RX_ERR bit is set
in netdev->msg_enable.
        eth2: No mem: dropped packet

        netdev_fatal(netdev, PROBE, "The EEPROM Checksum Is Not Valid\n");
or
        netdev_err(netdev, ALL, "The EEPROM Checksum Is Not Valid\n");
unconditionally logs a message such as:
        eth%d (e1000 0000:00:03.0): The EEPROM Checksum Is Not Valid
The message's prefix includes the driver name and bus ID because the
message is logged at probe time, before netdev is registered.

SAMPLE DRIVERS
As examples of how the netdev_* macros could be used, patches for the
v2.6.0-test11 e100, e1000, and tg3 drivers are available on request.

LINUX v2.4 SUPPORT
Since there is no v2.6-style struct device underlying the net_device,
a v2.4.23-compatible version of netdev_printk would always log the
interface name as the message prefix:

#define netdev_printk(sevlevel, netdev, msglevel, format, arg...)	\
do {									\
	if (NETIF_MSG_##msglevel == NETIF_MSG_ALL			\
	    || (netdev->msg_enable & NETIF_MSG_##msglevel)) {		\
		printk(sevlevel "%s: " format , netdev->name , ## arg);	\
	}								\
} while (0)

Jim Keniston
IBM Linux Technology Center