Wolfgang Grandegger wrote:

David Miller wrote:

quoted

From: Arnd Bergmann <arnd@arndb.de>
Date: Tue, 26 May 2009 10:10:30 +0100

quoted

On Monday 25 May 2009, Wolfgang Grandegger wrote:

quoted

quoted

Right, that makes sense. However, most drivers use the field to store the
physical address, not the iomap token. Maybe there should be a new field
in struct sja1000_priv for the virtual address, but that would be a change
to the base driver, not just to the OF portion.

Is that common practice? If yes, I will add a member to store the
virtual address to struct sja1000_priv.

I grepped through the network driver for usage of ->base_addr, and
it's somewhat inconsistent. The majority of the users use it for
a physical address, but there are also a few that use it for the
__iomem token.

Casts between unsigned long and qualified (__iomem, __user, const, ...)
pointers do not cause a warning, but can easily lead to bugs when
another user casts to an unqualified pointer.

It's such a baroque thing, there is no reason to set it at all if you
ask me.  It's only use is to allow ISA and similar primitive bus
devices to have their I/O ports changed via ifconfig.

OK, I see, there are good reasons not to (mis-)use dev->base_addr. I
will prepare a patch for the SJA1000 CAN drivers.

I have just sent out a patch series fixing this issue and providing
a revised patch for the SJA1000 OF platform driver:

[net-next-2.6 PATCH 0/3] can: sja1000: misused netdev->base_addr and OF platform driver

Wolfgang.