Re: [PATCH] compat: backport linux/pci-aspm.h

["Luis R. Rodriguez" <lrodriguez@atheros.com>]

On Thu, Sep 02, 2010 at 06:18:00AM -0700, Hauke Mehrtens wrote:
> Am 01.09.2010 17:12, schrieb Luis R. Rodriguez:
> > On Wed, Sep 1, 2010 at 8:07 AM, Hauke Mehrtens <hauke@hauke-m.de> wrote:
> >> Am 28.08.2010 23:01, schrieb Luis R. Rodriguez:
> >>> On Fri, Aug 27, 2010 at 11:41:54AM -0700, Hauke Mehrtens wrote:
> >>>> pci-aspm.h was introduced in kernel 2.6.25 and is used by the ath5k driver.
> >>>>
> >>>> Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
> >>>> ---
> >>>>  include/linux/pci-aspm.h |   55 ++++++++++++++++++++++++++++++++++++++++++++++
> >>>>  1 files changed, 55 insertions(+), 0 deletions(-)
> >>>>  create mode 100644 include/linux/pci-aspm.h
> >>>>
> >>>> diff --git a/include/linux/pci-aspm.h b/include/linux/pci-aspm.h
> >>>> new file mode 100644
> >>>> index 0000000..c791d00
> >>>> --- /dev/null
> >>>> +++ b/include/linux/pci-aspm.h
> >>>
> >>> So compat-wireless would have to copy this file over? We'd then have to synch
> >>> this file for older kernels, and the real kernel header's own pci-aspm.h for
> >>> kernels >= 2.6.25 would be using this version of the file. Can we just stuff
> >>> the ASPM required stuff onto include/linux/compat-2.6.25.h ?
> >>>
> >>>   Luis
> >> Hi,
> >>
> >> we can stuff the empty aspm functions into compat-2.6.25.h, but we need
> >> include/linux/pci-aspm.h or we need an extra ifdef in compat-wireless
> >> (not nice). Some drivers like drivers/net/wireless/ath/ath5k/base.c and
> >> drivers/net/wireless/iwlwifi/iwl-agn.c are including pci-aspm.h, but it
> >> is not there for kernels < 2.6.25.
> > 
> > Understood and good point.
> > 
> >> I will prepare a new patch for compat. With an mostly empty pci-aspm.h
> >> with an include_next and some functions in compat-2.6.35.h.
> > 
> > Well so the issue is getting kernels newer than include their own
> > kernel header's include/linux/pci-aspm.h rather than the one provided
> > by compat. How will this be achieved?
> 
> #include_next includes the next file with this name.
> http://www.delorie.com/gnu/docs/gcc/cpp_11.html (middle)
> We can do it like it is done in include/linux/tracepoint.h in compat.
> If something changes in pci-aspm.h in the kernel we do not have to
> change anything for kernel > 2.6.25.

Fair enough and thanks for the reference! Sounds good!

  Luis