From mboxrd@z Thu Jan 1 00:00:00 1970 From: john stultz Date: Fri, 31 Aug 2007 18:46:39 +0000 Subject: RE: git pull on ia64 linux tree Message-Id: <1188585999.6479.3.camel@localhost.localdomain> List-Id: References: <200504222203.j3MM3fV17003@unix-os.sc.intel.com> In-Reply-To: <200504222203.j3MM3fV17003@unix-os.sc.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-ia64@vger.kernel.org On Fri, 2007-08-31 at 01:37 -0700, Linus Torvalds wrote: > > On Thu, 30 Aug 2007, Linus Torvalds wrote: > > > > So there are two cases: > > > > - either the code is already only used on ia64, and nobody else will > > care. > > > > In this case, the patch is pointless. > > > > - or it's used by others, and others *will* care, and (judging by the > > probably intent of the bogus initializer) they may then die a horrible > > death. > > > > In this case, the patch is actively evil, and should not have come in > > through an ia64 merge. > > > > In other words, either it's pointless, or it's really really bad. Please > > explain to me why I should pull this, especially this late in the -rc > > game? > > Having looked closer, it looks like the magic actually disables some > broken code from happening on other architectures. > > However, why was it done in that illogical manner? > > It would appear that what you actually wanted to happen in that commit was > to make sure that the clocksource didn't get registered. If so, the > logical patch would be something like the appended instead, which would > disable the code that registers it the _obvious_ way, instead of > initializing a variable to a bad pointer and then relying on the bad > pointer to disable the code. > > So can somebody explain to me why it was done in that really odd way? Sorry, that's me. I just got smacked earlier for #ifdef's in code, so I figured by initializing hpet_clocksource to a junk value it wouldn't get initialized, and kept the #ifdefs outside functions. I'll agree it is more obfuscated, and yours is much more straight forward. Apologies, apparently I'm still learning the balance. -john > --- > drivers/char/hpet.c | 3 +++ > 1 files changed, 3 insertions(+), 0 deletions(-) > > diff --git a/drivers/char/hpet.c b/drivers/char/hpet.c > index 77bf4aa..7ecffc9 100644 > --- a/drivers/char/hpet.c > +++ b/drivers/char/hpet.c > @@ -909,6 +909,8 @@ int hpet_alloc(struct hpet_data *hdp) > > hpetp->hp_delta = hpet_calibrate(hpetp); > > +/* This clocksource driver currently only works on ia64 */ > +#ifdef CONFIG_IA64 > if (!hpet_clocksource) { > hpet_mctr = (void __iomem *)&hpetp->hp_hpet->hpet_mc; > CLKSRC_FSYS_MMIO_SET(clocksource_hpet.fsys_mmio, hpet_mctr); > @@ -918,6 +920,7 @@ int hpet_alloc(struct hpet_data *hdp) > hpetp->hp_clocksource = &clocksource_hpet; > hpet_clocksource = &clocksource_hpet; > } > +#endif > > return 0; > }