On 13 January 2017 at 14:19, Mark Rutland <mark.rutl...@arm.com> wrote: > On Thu, Jan 12, 2017 at 01:47:32PM +0000, Ryan Harkin wrote: >> On 12 January 2017 at 12:25, Mark Rutland <mark.rutl...@arm.com> wrote: >> > On Tue, Jan 10, 2017 at 06:50:19PM +0000, Jon Medhurst (Tixy) wrote: >> >> On Tue, 2017-01-10 at 18:34 +0000, Mark Rutland wrote: >> >> > Looking at the git log for arch/arm64/boot/dts/arm, most updates are >> >> > simply adding new descriptions, so a DTB from a year ago should work >> >> > just fine with mainline (modulo the Juno PCI window issue, which was a >> >> > DTB bug). Upgrading kernel shouldn't require a DTB upgrade to see >> >> > equivalent functionality. > >> > The key point is that it is possible to provide a baseline DTB that is >> > good enough for most users, and will work with future kernels. >> > >> > We're unlikely to get to a state where DTBs are perfect and complete >> > from day one. We can have something that remains usable. >> >> I hope it stays that way. Most of my users are either on 3.18 or 4.4. >> And they are incompatible with each other w.r.t. DTBs to the point >> where one won't even post a banner message with the other's DTB. > > Interesting. Just to check, do you mean v3.19? There was no upstream > Juno DT in v3.18. > > Unfortunately, I can't spot any DT changes between v3.19 and v4.4 that > would obviously break compatibility such that serial wouldn't work. > > If you have those kernels && DTBs to hand, are you able to take a look > if passing "earlycon=pl011,0x7ff80000"? > > I know that the ARM Software linux repo shipped a broken DT, along with > some kernel modifications which bodge around that (specifically, they > exposed a broken MMIO timer as functional). IIRC, Poking that would > bring down the kernel, before the serial wa up. > > Is your v3.18 DT the old ARM Software repo's Juno DT? >
I don't have any of the data points any more, but it wasn't due to the ARMLT tree, which tends to be stable/reliable. It was mostly debian vs upstream. > Thanks, > Mark. _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot