Re: driver probe error reporting

[Greg KH <greg@kroah.com>]

On Mon, Dec 15, 2008 at 11:15:02PM +0000, Ben Dooks wrote:
> This runs on from the discussion in [1] on how drivers (especially
> one using a variant of the device driver framework) report errors
> on probe. There are two main classes of errors, the type which happen
> at probe time (device not responding, not enough memory, etc) and
> errors that are due to configuration such as missing device configuration
> data.
> 
> It has been suggested that using dev_err() to report any configuration
> data error is a bloat of code as a properly debugged kernel should never
> find itself in this state.
> 
> Unfortunatley the only diagnostic dev_xxx() macro is dev_dbg() which is
> only available if the the driver code itself defines DEBUG. I would think
> it would be better to have a macro that can be turned on/off by a kernel
> configuration for when debugging which turns on the messages that are
> important to developers creating new machine/arch support but disabled
> for shipping kernels.

Not anymore, dev_dbg() can be dynamically switched on and off at runtime
in 2.6.28.

> Basically, what are people's thoughts on a "Verbose probe error"
> configuration option in the "Kernel hacking" submenu with its own
> dev_probe_err() or similar macro?

It is not needed, see the above :)

thanks,

greg k-h