On 02/18/18 17:46, Rob Herring wrote: > On Sun, Feb 18, 2018 at 6:29 PM, <frowand.list@xxxxxxxxx> wrote: >> From: Frank Rowand <frank.rowand@xxxxxxxx> >> >> kbuild test robot reported a new warning for a recent patch: >>>> drivers/of/overlay.c:832:2: error: implicit declaration of function 'of_fdt_unflatten_tree' [-Werror=implicit-function-declaration] >> of_fdt_unflatten_tree(new_fdt, NULL, &overlay_root); >> >> The cause is that the prototype for of_fdt_unflatten_tree() in >> include/linux/of_fdt.c is guarded by OF_EARLY_FLATTREE. >> >> This was a pre-existing problem for any overlay related caller of >> of_fdt_unflatten_device_tree(), who was then going to pass the >> unflattened tree to of_overlay_apply(). After the patch that triggered >> this warning, all other overlay callers of of_fdt_unflatten_device_tree() >> no longer exist, so adding the select to OF_OVERLAY is a sufficient fix. >> >> To reproduce the warning: >> Use the .config attached to https://lkml.org/lkml/2018/2/17/268 >> make ARCH=i386 olddefconfig >> make ARCH=i386 CC=gcc-7 drivers/of/overlay.o >> >> Signed-off-by: Frank Rowand <frank.rowand@xxxxxxxx> >> --- >> drivers/of/Kconfig | 1 + >> 1 file changed, 1 insertion(+) >> >> diff --git a/drivers/of/Kconfig b/drivers/of/Kconfig >> index 783e0870bd22..00a6abfaaec7 100644 >> --- a/drivers/of/Kconfig >> +++ b/drivers/of/Kconfig >> @@ -92,6 +92,7 @@ config OF_RESOLVE >> config OF_OVERLAY >> bool "Device Tree overlays" >> select OF_DYNAMIC >> + select OF_EARLY_FLATTREE > > If we do this, we might as well kill OF_EARLY_FLATTREE. What platform > really boots from not FDT, but uses DT without overlays? Making sure I'm understanding... So you want to remove OF_EARLY_FLATTREE and convert the current users of it to OF_FLATTREE? I don't see any way to directly configure OF_FLATTREE and I don't see any Kconfig file selecting it, other than drivers/of/Kconfig which selects OF_FLATTREE from OF_EARLY_FLATTREE. So as far as I can tell, the two config options are essentially a single config option. Meaning that either one could be replaced by the other. Changing all to OF_FLATTREE will touch more files and thus will be a bit more obtrusive. It looks like it would take two releases to avoid a flag day change. Changing all to OF_EARLY_FLATTREE can be done in a single release. I can create a patch set whichever way you prefer. -Frank -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
