On Fri, Jan 15, 2021 at 11:14:50AM +0530, Viresh Kumar wrote: > +David, > > On 14-01-21, 09:01, Rob Herring wrote: > > On Wed, Jan 13, 2021 at 11:03 PM Viresh Kumar wrote: > > > > > > On 11-01-21, 09:46, Rob Herring wrote: > > > > On Fri, Jan 8, 2021 at 2:41 AM Viresh Kumar wrote: > > > > > > > > > > Now that fdtoverlay is part of the kernel build, start using it to test > > > > > the unitest overlays we have by applying them statically. > > > > > > > > Nice idea. > > > > > > > > > The file overlay_base.dtb have symbols of its own and we need to apply > > > > > overlay.dtb to overlay_base.dtb alone first to make it work, which gives > > > > > us intermediate-overlay.dtb file. > > > > > > > > Okay? If restructuring things helps we should do that. Frank? > > > > > > Frank, do we want to do something about it ? Maybe make overlay_base.dts an dtsi > > > and include it from testcases.dts like the other ones ? > > > > No, because overlay_base.dts is an overlay dt. So.. I was confused for a bit here, because the overlay_base.dts you're discussing is the one in the kernel tree, not the one in the dtc tree. The kernel file is confusing to me. It has the /plugin/ tag which should be used for overlays, but the rest of the file looks like a base tree rather than an overlay. There's even a comment saying "Base device tree that overlays will be applied against". But it goes on to talk about __fixups__ and __local__fixups__ which will never be generated for a based tree. Oh.. and then there's terminology confusion. dtc has had compile time resolved overlays for a very long time. Those are usually .dtsi files, and should generally not have /plugin/. More recent is the support for run-time overlays - .dtbo output files, which are usually generated from a .dts with /plugin/. They usually should *not* have a "/ { ... } " stanza, since that indicates the base portion of the tree. > What property of a file makes it an overlay ? Just the presence of > /plugin/; ? Yes and no. Generally that's how it should work , but it looks to me like the presence of /plugin/ there is just wrong. /plugin/ basically just activates some extra dtc features, though, so it is possible to "manually" construct a valid overlay without it. > David, we are talking about the overlay base[1] file here. The > fdtoverlay tool > fails to apply it to testcases.dts file (in the same directory) because none of > its nodes have the __overlay__ label and the dtc routine overlay_merge() [2] > skips them intentionally. testcases.dts also has /plugin/ and again, it's not really clear if that's right. The point of /plugin/ is that it will automatically generate the __overlay__ subnodes from dtc's &label { ... } or &{/path} { ... } syntax, so you wouldn't expect to see __overlay__ in the source. > > I think we need an > > empty, minimal base.dtb to apply overlay_base.dtbo to. > > One way out is adding an (almost-empty) testcase-data-2 in testcases.dtb, that > will make it work. > > > And then fdtoverlay needs a fix to apply overlays to the root node? > > It isn't just root node I think, but any node for which the __overlay__ label > isn't there. > > So this can make it all work if everyone is fine with it: > > diff --git a/drivers/of/unittest-data/overlay_base.dts b/drivers/of/unittest-data/overlay_base.dts > index 99ab9d12d00b..59172c4c9e5a 100644 > --- a/drivers/of/unittest-data/overlay_base.dts > +++ b/drivers/of/unittest-data/overlay_base.dts > @@ -11,8 +11,7 @@ > * dtc will create nodes "/__symbols__" and "/__local_fixups__". > */ > > -/ { > - testcase-data-2 { > + &overlay_base { > #address-cells = <1>; > #size-cells = <1>; > > @@ -89,5 +88,3 @@ retail_1: vending@50000 { > }; > > }; > -}; > - > diff --git a/drivers/of/unittest-data/testcases.dts b/drivers/of/unittest-data/testcases.dts > index a85b5e1c381a..539dc7d9eddc 100644 > --- a/drivers/of/unittest-data/testcases.dts > +++ b/drivers/of/unittest-data/testcases.dts > @@ -11,6 +11,11 @@ node-remove { > }; > }; > }; > + > + overlay_base: testcase-data-2 { > + #address-cells = <1>; > + #size-cells = <1>; > + }; > > -------------------------8<------------------------- > > And then we can do this to the Makefile over my changes. > > -------------------------8<------------------------- > > diff --git a/drivers/of/unittest-data/Makefile b/drivers/of/unittest-data/Makefile > index 9f3eb30b78f1..8cc23311b778 100644 > --- a/drivers/of/unittest-data/Makefile > +++ b/drivers/of/unittest-data/Makefile > @@ -41,7 +41,6 @@ DTC_FLAGS_testcases += -Wno-interrupts_property > > # Apply all overlays (except overlay_bad_* as they are not supposed to apply and > # fail build) statically with fdtoverlay > -intermediate-overlay := overlay.dtb > master := overlay_0.dtb overlay_1.dtb overlay_2.dtb \ > overlay_3.dtb overlay_4.dtb overlay_5.dtb \ > overlay_6.dtb overlay_7.dtb overlay_8.dtb \ > @@ -50,15 +49,12 @@ master := overlay_0.dtb overlay_1.dtb overlay_2.dtb \ > overlay_gpio_01.dtb overlay_gpio_02a.dtb \ > overlay_gpio_02b.dtb overlay_gpio_03.dtb \ > overlay_gpio_04a.dtb overlay_gpio_04b.dtb \ > - intermediate-overlay.dtb > + overlay_base.dtb overlay.dtb > > quiet_cmd_fdtoverlay = fdtoverlay $@ > cmd_fdtoverlay = $(objtree)/scripts/dtc/fdtoverlay -o $@ -i $^ > > -$(obj)/intermediate-overlay.dtb: $(obj)/overlay_base.dtb $(addprefix $(obj)/,$(intermediate-overlay)) > - $(call if_changed,fdtoverlay) > - > $(obj)/master.dtb: $(obj)/testcases.dtb $(addprefix $(obj)/,$(master)) > $(call if_changed,fdtoverlay) > > -always-$(CONFIG_OF_OVERLAY) += intermediate-overlay.dtb master.dtb > +always-$(CONFIG_OF_OVERLAY) += master.dtb > -- David Gibson | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_ | _way_ _around_! http://www.ozlabs.org/~dgibson