Re: [PATCH 22/82] remove linux/version.h from drivers/message/fus ion

[Matt Domsch <Matt_Domsch@dell.com>]

On Tue, Jul 19, 2005 at 06:07:41PM -0600, Moore, Eric Dean wrote:
> On Tuesday, July 12, 2005 8:17 PM, Matt Domsch wrote:
> > In general, this construct:
> > 
> > > > -#if (LINUX_VERSION_CODE < KERNEL_VERSION(2,6,6))
> > > > -static int inline scsi_device_online(struct scsi_device *sdev)
> > > > -{
> > > > -	return sdev->online;
> > > > -}
> > > > -#endif
> > 
> > is better tested as:
> > 
> > #ifndef scsi_device_inline
> > static int inline scsi_device_online(struct scsi_device *sdev)
> > {
> >     return sdev->online;
> > }
> > #endif
> > 
> > when you can.  It cleanly eliminates the version test, and tests for
> > exactly what you're looking for - is this function defined.
> > 
> 
> What you illustrated above is not going to work.
> If your doing #ifndef around a function, such as scsi_device_online, it's
> not going to compile
> when scsi_device_online is already implemented in the kernel tree.
> The routine scsi_device_online is a function, not a define.  For a define
> this would work.

Sure it does, function names are defined symbols.

I'm doing exactly this in my backport of the openipmi drivers to RHEL4
and SLES9.

> I'm trying your example around msleep, msleep_interruptible, and
> msecs_to_jiffies, and 
> my code simply won't compile in SLES9 SP2(-191).  In SLES9 SP1(-139), these
> three routines were not implemented and
> your suggestion works.  I won't be able to to a linux version check as this
> change occurred between service packs
> of the 2.6.5 kernel suse tree.   Anybody on the linux forums have any ideas?
> 
> Example:
> 
> #ifdef msleep

#ifndef  you mean.

> static void inline msleep(unsigned long msecs)
> {
>         set_current_state(TASK_UNINTERRUPTIBLE);
>         schedule_timeout(msecs_to_jiffies(msecs) + 1);
> }
> #endif


Thanks,
Matt

-- 
Matt Domsch
Software Architect
Dell Linux Solutions linux.dell.com & www.dell.com/linux
Linux on Dell mailing lists @ http://lists.us.dell.com