Masahiro Yamada [off-list ref] writes:

On Tue, Dec 15, 2020 at 12:29 PM Michael Ellerman [off-list ref] wrote:

quoted

The lkp robot reported that some configs fail to build, for example
mpc85xx_smp_defconfig, with:

  cc1: fatal error: opening output file arch/powerpc/boot/dts/fsl/.mpc8540ads.dtb.dts.tmp: No such file or directory

This bisects to:
  cc8a51ca6f05 ("kbuild: always create directories of targets")

Although that commit claims to be about in-tree builds, it somehow
breaks out-of-tree builds. But presumably it's just exposing a latent
bug in our Makefiles.

We can fix it by adding to targets for dts/fsl in the same way that we
do for dts.

Fixes: cc8a51ca6f05 ("kbuild: always create directories of targets")
Reported-by: kernel test robot <redacted>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
---
 arch/powerpc/boot/Makefile | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/powerpc/boot/Makefile b/arch/powerpc/boot/Makefile
index 68a7534454cd..c3e084cceaed 100644
--- a/arch/powerpc/boot/Makefile
+++ b/arch/powerpc/boot/Makefile

@@ -372,6 +372,8 @@ initrd-y := $(filter-out $(image-y), $(initrd-y))
 targets        += $(image-y) $(initrd-y)
 targets += $(foreach x, dtbImage uImage cuImage simpleImage treeImage, \
                $(patsubst $(x).%, dts/%.dtb, $(filter $(x).%, $(image-y))))
+targets += $(foreach x, dtbImage uImage cuImage simpleImage treeImage, \
+               $(patsubst $(x).%, dts/fsl/%.dtb, $(filter $(x).%, $(image-y))))

 $(addprefix $(obj)/, $(initrd-y)): $(obj)/ramdisk.image.gz

Some freescale dts files are right under arch/powerpc/boot/dts/,
but some are in the fsl/ subdirectory.
I do not understand the policy.

There isn't a policy. Best I can tell Kumar felt like it would be
cleaner to have a separate directory for (some of) the Freescale DTS
files, when he initially submitted them ~9 years ago.

If "fsl/" is a very special case,
I just thought we could add a new syntax, fslimage-y,
but I do not mind either way.

OK. If you don't mind I'll merge my patch as a quick fix for now.

Then we can probably move all the fsl/ files up one level and avoid the
problem entirely in future.

fslimage-$(CONFIG_MPC8540_ADS) += cuImage.mpc8540ads

targets += $(foreach x, dtbImage uImage cuImage simpleImage treeImage, \
               $(patsubst $(x).%, dts/fsl/%.dtb, $(filter $(x).%,
$(fslimage-y))))


This Makefile is wrong over-all anyway.

Excellent.

cheers