On 10 Sep 01, Loïc Minier wrote: > On Wed, Sep 01, 2010, Amit Kucheria wrote: > > That patch likely won't go upstream. > > Why not?
Because it adds a sub-arch, revision-specific override into generic architecture code (vfpmodule.c) To do this elegantly with a hope to get it to mainline, we'd need a way to disable the hwcap through some board-specific fixup code that can check the revision of the board at runtime. Unfortunately, it seems after talking to Nicolas that mdesc->fixup() is called too early. Nicolas suggested linking the i.MX5 code _after_ the VFP module :) > > OTOH, how important is support below TO3? > > For Linaro, not too important I guess, some people have TO2 hardware, > some Babbage 2.0 or 2.5, albeit 2.0 is not really supported anymore. > EfikaMX also comes in both TO2 and TO3. Finally, some mass-market / > public hardware like Sharp Netwalker are TO2 based. > > > TO1 won't even boot on Freescale's BSP, IIRC. AFAICT, Freescale isn't > > testing > > their BSP on TO2 if you take into account bugs like LP # 615722 [1] that > > caused bricking of Babbage 2.5 boards. And new HW is all TO3 and so is all > > known production HW. We only have a few TO2 boards now those will get > > rapidly > > get discarded when we get newer ones. > > Some months back, in the beginning of this year, I heard of commercial > projects targetting TO2 to save some money on the chip. There's also > some mass-market / public TO2 hardware in the form of the netwalker. I hope they didn't get bitten by the bricking problems. > > So, IMHO, enable NEON support and add to release-notes that TO1/2 is not > > supported. > > We can do that in Linaro, I'm just a bit uncomfortable that there is a > non-trivial amount of TO2 devices out there, and it's a DoS issue to > have this NEON flaw. > > I would be ok if we would only support TO3 and the kernel wouldn't boot > on TO2 hardware, but AIUI the kernel will boot just fine and turn on > NEON on TO2 such as Babbage 2.x, so I'm a bit scared by just release > noting it. Another solution is that we could perhaps add code in the board init function to check the cpu revision and if NEON was enabled, then stop booting. /Amit _______________________________________________ linaro-dev mailing list linaro-dev@lists.linaro.org http://lists.linaro.org/mailman/listinfo/linaro-dev
