Date: Thu, 19 Sep 1996 00:30:36 -0700 From: David Greenman <dg@root.com> To: hm@kts.org Cc: durian@plutotech.com, msmith@atrad.adelaide.edu.au, freebsd-hackers@FreeBSD.org Subject: Re: Special Cycles on the PCI bus Message-ID: <199609190730.AAA01730@root.com> In-Reply-To: Your message of "Thu, 19 Sep 1996 07:29:39 %2B0200." <m0v3bgB-00000bC@ernie.kts.org>
next in thread | previous in thread | raw e-mail | index | archive | help
>David Greenman wrote: > >> Perhaps they are caused by the inb(0x84)'s that are used as time delays in >> a couple places of the kernel. The inb(0x84) is supposed to be an unused port >> and thus should take about 1.25us to read from. This isn't always true, >> however, as people have pointed out in the past. We should probably replace >> the last few places where these are used with a calibrated wait loop. > >And then the old question appears again - how to do (relatively) precise >delays in the range of 1 us ... 10 us. As far as i understood Bruce that >time, DELAY isn't able to handle this precisely. Has that changed ? Right, this is one of the problems that needs to be resolved first. -DG David Greenman Core-team/Principal Architect, The FreeBSD Project
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?199609190730.AAA01730>