[Intel-gfx] [PATCH 2/2] drm/i915: add header search path to subdir Makefiles

[Jani Nikula]

With the subdirectories we lost the ability to build individual files on
the command line, for example:

$ make drivers/gpu/drm/i915/display/intel_display.o

This was due to the top level directory missing from header search
path. Add the header search paths to subdir Makefiles.

Note that none of the other options in the top level i915 Makefile are
taken into account when building individual files. Usually this is not a
concern.

Reported-by: Imre Deak <imre.deak at intel.com>
Reported-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
Cc: Chris Wilson <chris at chris-wilson.co.uk>
Signed-off-by: Jani Nikula <jani.nikula at intel.com>
---
 drivers/gpu/drm/i915/display/Makefile | 3 +++
 drivers/gpu/drm/i915/gem/Makefile     | 6 +++++-
 drivers/gpu/drm/i915/gt/Makefile      | 3 +++
 3 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/display/Makefile b/drivers/gpu/drm/i915/display/Makefile
index 1c75b5c9790c..eec6961015a1 100644
--- a/drivers/gpu/drm/i915/display/Makefile
+++ b/drivers/gpu/drm/i915/display/Makefile
@@ -1,2 +1,5 @@
+# For building individual subdir files on the command line
+subdir-ccflags-y += -I$(srctree)/$(src)/..
+
 # Extra header tests
 include $(src)/Makefile.header-test
diff --git a/drivers/gpu/drm/i915/gem/Makefile b/drivers/gpu/drm/i915/gem/Makefile
index 07e7b8b840ea..eec6961015a1 100644
--- a/drivers/gpu/drm/i915/gem/Makefile
+++ b/drivers/gpu/drm/i915/gem/Makefile
@@ -1 +1,5 @@
-include $(src)/Makefile.header-test # Extra header tests
+# For building individual subdir files on the command line
+subdir-ccflags-y += -I$(srctree)/$(src)/..
+
+# Extra header tests
+include $(src)/Makefile.header-test
diff --git a/drivers/gpu/drm/i915/gt/Makefile b/drivers/gpu/drm/i915/gt/Makefile
index 1c75b5c9790c..eec6961015a1 100644
--- a/drivers/gpu/drm/i915/gt/Makefile
+++ b/drivers/gpu/drm/i915/gt/Makefile
@@ -1,2 +1,5 @@
+# For building individual subdir files on the command line
+subdir-ccflags-y += -I$(srctree)/$(src)/..
+
 # Extra header tests
 include $(src)/Makefile.header-test
-- 
2.20.1