re: [PATCH] of: unittest: Statically apply overlays using fdtoverlay

From: frowand.list@gmail.com
To: Viresh Kumar <viresh.kumar@linaro.org>,
	Rob Herring <robh+dt@kernel.org>,
	pantelis.antoniou@konsulko.com
Cc: devicetree@vger.kernel.org, linux-kernel@vger.kernel.org,
	linux-kbuild@vger.kernel.org,
	Vincent Guittot <vincent.guittot@linaro.org>,
	Bill Mills <bill.mills@linaro.org>,
	anmar.oueja@linaro.org, Masahiro Yamada <masahiroy@kernel.org>
Subject: re: [PATCH] of: unittest: Statically apply overlays using fdtoverlay
Date: Mon, 18 Jan 2021 20:21:54 -0600	[thread overview]
Message-ID: <20210119022154.2338781-1-frowand.list@gmail.com> (raw)
In-Reply-To: <1e42183ccafa1afba33b3e79a4e3efd3329fd133.1610095159.git.viresh.kumar@linaro.org>

From: Frank Rowand <frank.rowand@sony.com>

These changes apply on top of the patches in:

  [PATCH] of: unittest: Statically apply overlays using fdtoverlay
  Message-Id: <1e42183ccafa1afba33b3e79a4e3efd3329fd133.1610095159.git.viresh.kumar@linaro.org>

There are still some issues to be cleaned up, so not ready for acceptance.

I have not used the construct "always-$(CONFIG_OF_OVERLAY)" before, and
have not looked into the proper usage of it.

I tested this using a hand build libfdt and fdtoverlay from the dtc-compiler
upstream project.  For my testing I added LD_LIBRARY_PATH to the body of
"cmd_fdtoverlay" to reference my hand built libfdt.  The kernel build
system will have to instead use a libfdt that is built in the kernel
tree.

I have not run this through checkpatch, or my checks for build warnings.
I have not run unittests on my target with these patches applied.

---
 drivers/of/unittest-data/Makefile | 67 ++++++++++++++++++++++---------
 1 file changed, 48 insertions(+), 19 deletions(-)

diff --git a/drivers/of/unittest-data/Makefile b/drivers/of/unittest-data/Makefile
index f17bce85f65f..28614a123d1e 100644
--- a/drivers/of/unittest-data/Makefile
+++ b/drivers/of/unittest-data/Makefile
@@ -39,25 +39,54 @@ DTC_FLAGS_testcases += -@
 # suppress warnings about intentional errors
 DTC_FLAGS_testcases += -Wno-interrupts_property
 
-# Apply overlays 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 \
-			   overlay_9.dtb overlay_10.dtb overlay_11.dtb \
-			   overlay_12.dtb overlay_13.dtb overlay_15.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
-
-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)
+# Apply overlays statically with fdtoverlay.  This is a build time test that
+# the overlays can be applied successfully by fdtoverlay.  This does not
+# guarantee that the overlays can be applied successfully at run time by
+# unittest, but it provides a bit of build time test coverage for those
+# who do not execute unittest.
+#
+# The overlays are applied on top of testcases.dtb to create static_test.dtb
+# If fdtoverlay detects an error than the kernel build will fail.
+# static_test.dtb is not consumed by unittest.
+#
+# Some unittest overlays deliberately contain errors that unittest checks for.
+# These overlays will cause fdtoverlay to fail, and are thus not included
+# in the static test:
+#			overlay.dtb \
+#			overlay_bad_add_dup_node.dtb \
+#			overlay_bad_add_dup_prop.dtb \
+#			overlay_bad_phandle.dtb \
+#			overlay_bad_symbol.dtb \
+
+apply_static_overlay := overlay_base.dtb \
+			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 \
+			overlay_9.dtb \
+			overlay_10.dtb \
+			overlay_11.dtb \
+			overlay_12.dtb \
+			overlay_13.dtb \
+			overlay_15.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 \
+
+quiet_cmd_fdtoverlay = FDTOVERLAY $@
+
+## This is not correct, need to use libfdt from the kernel tree:
+cmd_fdtoverlay = $(objtree)/scripts/dtc/fdtoverlay -o $@ -i $^
 
-$(obj)/master.dtb: $(obj)/testcases.dtb $(addprefix $(obj)/,$(master))
+$(obj)/static_test.dtb: $(obj)/testcases.dtb $(addprefix $(obj)/,$(apply_static_overlay))
 	$(call if_changed,fdtoverlay)
 
-always-$(CONFIG_OF_OVERLAY) += intermediate-overlay.dtb master.dtb
+always-$(CONFIG_OF_OVERLAY) += static_test.dtb
-- 
Frank Rowand <frank.rowand@sony.com>

