With a non-constant 8-bit argument, a call to udelay() generates a warning:
drivers/gpu/drm/radeon/atom.c: In function 'atom_op_delay':
drivers/gpu/drm/radeon/atom.c:654: warning: comparison is always false due to limited range of data type
The code looks like it works OK with an 8-bit arg, and the calling code is
doing nothing wrong, so udelay() needs fixing.
Fixing it was rather tricky. Simply typecasting `n' in the comparison with
20000 didn't change anything. Hence the divide-by-20000 trick.
Using a do{}while loop didn't work because udelay() is used in ?: statements,
hence the ({...}) construct.
While I was there I replaced the brain-bending ?:?:?: mess with nice if/else
code.
Probably other architectures are generating the same warning and can use a
similar change.
[Taken from the x86 tree and moved to asm-generic by Jonas Bonn]
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jonas Bonn <jonas@southpole.se>
Several architectures are using a common delay.h implementation that
appears to have originated with the x86 architecture. This common
implementation is a bit fuller than the current asm-generic version
and has some compile-time checks that should be interesting for all
architectures.
This patch takes the common delay.h version and replaces the rather
trivial asm-generic version with it. As no architecture was actually
using asm-generic/delay.h, this change is rather innocuous; it will,
however, allow us to switch at least four architectures over to using
the asm-generic version.
Signed-off-by: Jonas Bonn <jonas@southpole.se>
Acked-by: Arnd Bergmann <arnd@arndb.de>
These are all kernel internal interfaces that get copied
around a lot. In most cases, architectures can provide
their own optimized versions, but these generic versions
can work as well.
I have tried to use the most common contents of each
header to allow existing architectures to migrate easily.
Thanks to Remis for suggesting a number of cleanups.
Signed-off-by: Remis Lima Baima <remis.developer@googlemail.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Andrew Morton
Jonas Bonn
Arnd Bergmann