On Thu, Jul 16, 2026 at 02:16:36PM -0600, James Hilliard wrote: > On Thu, Jul 16, 2026 at 2:03 PM Tom Rini <[email protected]> wrote: > > > > On Sun, Jun 28, 2026 at 03:27:48PM -0600, James Hilliard wrote: > > > On Sun, Jun 28, 2026 at 10:16 AM Andre Przywara <[email protected]> > > > wrote: > > > > > > > > On Fri, 26 Jun 2026 14:51:50 -0600 > > > > James Hilliard <[email protected]> wrote: > > > > > > > > Hi James, > > > > > > > > > sunxi SPL normally uses the legacy MMC interface while U-Boot > > > > > proper uses the DM driver. Boards which enable SPL_DM_MMC need > > > > > > > > I think I mentioned this before: enabling the device model in the SPL > > > > (or not) is not a *device* decision, but a platform one. > > > > > > I'm a bit confused here, uboot's configuration system from what I can tell > > > is designed to allow enabling device model for specific devices and even > > > for specific drivers. > > > > Right. And to be clear, in your tree you're working to upstream out of, > > only the h616 platforms end up enabling SPL_DM and not all of the > > existing ARCH_SUNXI, yes? > > Well my uboot config is managed out of tree by buildroot technically. I've > only > tested on h616 myself. AFAIU SPL_DM for sunxi is not disabled by kconfig > on sunxi platform as-is, it's just a bit broken at runtime I think. > > > > > > Why would this need to be a platform level decision? Given that boards > > > that don't have enough SRAM for SPL DM support tend to be older, we > > > will presumably want to migrate newer boards to SPL DM at some point > > > in the future anyways. > > > > > > > And for > > > > technical reasons, mostly to support older devices, which have no other > > > > choice, but also to keep it simple and the SPL small, we do not use DM > > > > in the SPL on Allwinner boards. > > > > > > I mean, this seems to me to be justification for continuing to support > > > legacy drivers, not justification for not supporting DM as well since > > > there > > > are also many sunxi boards that don't have that limitation. > > > > This would be a separate set of potential cleanups to evaluate later on. > > > > > > I see the SPL as the continuation of the > > > > BootROM, which is completely board agnostic. > > > > > > At a minimum SPL is still fairly SoC specific. Although in practice it > > > seems > > > to not be all that board agnostic, I think if anything DM support makes it > > > more agnostic by allowing better factoring of the device specific stuff. > > > > > > > The SPL can mimic this > > > > behaviour, to follow the decisions that the BootROM made, for instance > > > > about the boot device. The only difference here is the DRAM > > > > initialisation, which requires some board specific data, but so far we > > > > got away with just hardcoding it. > > > > > > This is one of a few reasons I wanted to get SPL DM functional on sunxi. > > > > > > > If that is not good anymore, I think > > > > we can find other solutions than pulling in the whole world of SPL_DM > > > > support. > > > > > > > > So what is the purpose of this exercise, why do you want DM_SPL > > > > supported? > > > > > > Some cryptoengine uboot drivers I was working on adding seemed to > > > need DM_SPL, also I think handling DRAM profiles becomes easier with > > > it somewhat. > > > > > > > Keep in mind that there are 178 Allwinner boards supported in > > > > U-Boot, so there better would be good reasons to change something > > > > fundamental like this for all of them. It changing it for a number of > > > > them is not better, because this doubles the test matrix, so we have to > > > > test now that it works on both legacy and DM_SPL boards - which frankly > > > > nobody will do. > > > > > > Well it doesn't actually double the test matrix since presumably boards > > > that are not SPL DM compatible will continue to use non-DM drivers only. > > > > And today nothing ARCH_SUNXI enables SPL, but they all could enable it > > today and get an assortment of failures. With what James is doing, some > > could now enable it and have it work, or more easily work. > > There are plenty of sunxi board configs in uboot with SPL enabled, I think > it's just SPL DM that's always disabled: > https://github.com/u-boot/u-boot/blob/v2026.07/configs/yuzukihd-chameleon_defconfig
Yes, oops, I mis-typed there. I meant to say SPL_DM. -- Tom
signature.asc
Description: PGP signature
