Date: Wed, 21 Jun 2017 19:13:24 -0600 From: Warner Losh <imp@bsdimp.com> To: Ronald Klop <ronald-lists@klop.ws> Cc: "freebsd-arm@freebsd.org" <freebsd-arm@freebsd.org> Subject: Re: Deorbiting armv4 and armv5 support Message-ID: <CANCZdfp0nKVtSTK9stUFoemEncx4KbGTzzpUGXoitvU1H%2BBUgg@mail.gmail.com> In-Reply-To: <CANCZdfpKRvmi24uvVUCKhKwxvDJRiUoEP1rkh7XO0sExJm2kWA@mail.gmail.com> References: <CANCZdfqj5nKvrbNg6woNkCLXyuyozS=z%2B6KFoxkXN3HMv44%2BAw@mail.gmail.com> <op.y1ood7ookndu52@53556c9c.cm-6-6b.dynamic.ziggo.nl> <CANCZdfpKRvmi24uvVUCKhKwxvDJRiUoEP1rkh7XO0sExJm2kWA@mail.gmail.com>
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On Sun, Jun 11, 2017 at 10:41 PM, Warner Losh <imp@bsdimp.com> wrote: > > > On Sun, Jun 11, 2017 at 3:28 PM, Ronald Klop <ronald-lists@klop.ws> wrote: > >> On Thu, 08 Jun 2017 22:22:51 +0200, Warner Losh <imp@bsdimp.com> wrote: >> >> Greetings, >>> >>> The pmap in armv4/5 has been broken for years at this point. It basically >>> works, but has issues with unaligned buffers. Since these have remained >>> unfixed for a long time, and most of the main ARM developers have given >>> up >>> trying to fix it, I think it would be best to retire the support rather >>> than waste people's time that seem to be working only to discover after a >>> lot of effort that it's busted. >>> >>> Since the consensus at the FreeBSD developer's summit appeared to be >>> 'let's >>> let it go'. It would remove the TARGET_ARCH arm and armeb. armv6 would >>> remain unaffected (though see a parallel thread). >>> >>> Warner >>> >> >> What branches are you talking about? >> > > I'm thinking only the -current branch. > > However, I'm thinking now that I'll write up something more formal (the > FCP process) and start maybe a 3 month timeout. There's two leads on a fix, > I'll be looking at one of them in the next few days. If one of these fixes > is good, I'll merge it. The second one is a long shot, though... > > So, my current plan is that if it remains unfixed by, say Sept 1, 2017, > I'll deorbit. I may adjust that date depending on the timing of the 12 > branch, since I want to get this resolved before the branch... > I've managed to get my old Atmel AT91SMA9G20 based board working, so I'm officially withdrawing this idea. I heard from a few people that had no issues with their armv5 boards and was wondering what I was talking about. I've found the root cause to my issues, so I think we're in good shape from a functional point of view. It looks like the unaligned issues that I'd seen in prior versions have been fixed at least since Feb of this year, maybe longer. As a side note, both the armv4 and armv6 busdma implementations work on armv4/5 hardware. Though the v6 implementation seems to use about 20-30% more memory in a quick test... Warner
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