On Fri, 2008-04-04 at 21:21 +0200, Johannes Berg wrote: > On Fri, 2008-04-04 at 10:20 -0700, Brad Boyer wrote: > > On Thu, Apr 03, 2008 at 05:44:44PM +0200, Johannes Berg wrote: > > > I don't see a reason for either of those mdelay()s, is there any? Works > > > fine for me without them... > > > > Which hardware revisions did you test? I suspect the mdelay calls were > > added to work around timing issues in one of the older PMU chips. Some > > of them are very timing sensitive, and sleep in particular is basically > > a pile of steps that got hacked until they worked on older systems. > > Mine's a 5,6 powerbook with PMU firmware 0x0c. The mdelay(100) seems > fairly large though for a point where we're out of pmu code already, and > the other one doesn't really seem too pmu related anyway. In any case, > just wanted to float that, don't see a particular need for it.
One of those was meant to let devices settle. The reason is that when waking from sleep, a lot of HW on the mobo is actually powered up (it was down during sleep). This delay comes from half paranoia / half experience, and is meant to ensure all those chips got a chance to settle and complete their power-on reset sequence before we start banging all over the place. Cheers, Ben. _______________________________________________ Linuxppc-dev mailing list [email protected] https://ozlabs.org/mailman/listinfo/linuxppc-dev
