On 18/04/17 16:57, Catalin Marinas wrote: > On Sun, Apr 16, 2017 at 09:04:46AM +0100, Russell King - ARM Linux wrote: >> On Sat, Apr 15, 2017 at 07:06:06PM -0500, Nisal Menuka wrote: >>> According to ARM, these errata exist only in a version of Cortex-A8 >>> (r2p0) which was never built. Therefore, I believe there are no platforms >>> where this workaround should be enabled. >>> link :http://infocenter.arm.com/help/index.jsp?topic= >>> /com.arm.doc.faqs/ka15634.html >> >> These were submitted by ARM Ltd back in 2009 - if the silicon was never >> built, there would've been no reason to submit them. Maybe Catalin can >> shed some light on this, being the commit author who introduced these? > > We normally try not to submit errata workarounds for revisions that are > not going to be built/deployed. It's possible that at the time there > were plans for r2p0 to be licensed and built (not just FPGA) but I don't > really remember the details. The A8 errata document indeed states that > r1p0 and r2p0 are obsolete but this can mean many things (like not > available to license). > > I'll try to see if any of the A8 past product managers know anything > about this. In the meantime, I would leave them in (no run-time > overhead).
FWIW, I just fired up a RealView PB-A8 board to check, and that reports r1p1. True, it's not strictly a real silicon implementation (I think it's one of the structured ASIC test chips), but since it was, as far as I'm aware, a commercially-available development system, it's not impossible that someone may still own and use one of these beasts. Robin.
