On Mon, Mar 08, 2021 at 09:42:43PM -0600, Bjorn Andersson wrote: > On Mon 08 Mar 20:56 CST 2021, Shawn Guo wrote: > > > On Mon, Mar 08, 2021 at 07:08:00PM -0600, Bjorn Andersson wrote: > > > On Thu 04 Mar 00:05 CST 2021, Shawn Guo wrote: > > > > > > > To support both ACPI and DT, it makes more sense to not use tiles for > > > > pinctrl-sc8180x driver, as ACPI table describes TLMM block with one > > > > single memory resource. Since DTS of SC8180X hasn't landed, there is > > > > still chance to align DT description with ACPI. > > > > > > > > > > I don't like the idea that we make up addresses to put in the DT to fit > > > what was put in the DSDT. It is 3 different memory regions, with things > > > in-between that Linux shouldn't touch. > > > > This is not a new idea but something pinctrl-sdm845 has been doing for > > years. And IMHO, it's not a bad idea but a reasonable compromise. > > > > SDM845 was the first platform where the previous contiguous TLMM block > was split up in tiles, at the time we didn't see a need to split it up. > > But then we hit QCS404 (iirc) where one of the tiles was way off and > concluded that we needed the DT binding to actually represent the > hardware - so the tiles concept was introduced. > > Unfortunately introducing the tiles back into sdm845 would cause issues > with existing DT, so that has not happened. > > > > Isn't it possible to during ACPI probe take reg 0 and register the 3 > > > named regions instead? > > > > It is possible. But let's see what it takes. We will need to have some > > quirk handling in the ACPI core to detect TLMM device on Flex 5G > > machine, and then override the memory resource registration for that > > device. Myself is not even convinced this is a good solution, not > > mentioning whether ACPI maintainers will accept it. > > > > I don't think this quirk should belong in the core. Can't you massage > the resources once you're in the probe function in pinctrl-sc8180x.c? Or > the platform resources can't be modified when we reach that point? Okay, I misread your comment. Yes, we can massage the resources, but it's a bit tricky. It took me hours get it right. Anyway, I will send it out for review. Hopefully we can agree on one solution out of three I have worked out. Shawn
