Applying patch to file in yocto recipe - patch

Question

I have a yocto recipe to compile a code from github. I modified some files and want to apply a patch to code fetched from github. Following is my recipe for building code.
SUMMARY = "Linux NFC stack for NCI based NXP NFC Controllers"
HOMEPAGE = "https://github.com/NXPNFCLinux/linux_libnfc-nci"
LICENSE = "Apache-2.0"
LIC_FILES_CHKSUM = "file://src/include/linux_nfc_api.h;endline=17;md5=42fdb99b3ff2c12f594b22a774cb7308"
SECTION = "libs"
SRC_URI = "git://github.com/NXPNFCLinux/linux_libnfc-nci.git \
file:///home/pratyush/Desktop/custom_board/drivers/PN7150/linux_libnfc-nci/demoapp-main-patch1.patch"
SRCREV = "7cf539d3d9c0d682c8da5968fbf5615ae9993060"
PV = "2.1+git${SRCPV}"
EXTRA_OECONF =" --enable-pn7150"
S = "${WORKDIR}/git"
inherit autotools
FILES_${PN} += "${libdir}/libnfc_nci_linux-1.so"
FILES_SOLIBSDEV = "${libdir}/libnfc_nci_linux.so"
Following my patch to applied
--- /home/root/PN7150/linux_libnfc-nci/Makefile.am
+++ Makefile.am
## -1,7 +1,7 ##
lib_LTLIBRARIES = libnfc_nci_linux.la
-sbin_PROGRAMS = nfcDemoApp
-nfcDemoApp_DEPENDENCIES = libnfc_nci_linux.la
+sbin_PROGRAMS = readNfc
+readNfc_DEPENDENCIES = libnfc_nci_linux.la
LDFLAGS = -Bstatic
## -9,13 +9,13 ##
LDFLAGS += -L$(openssldir)/lib -lcrypto -lssl
endif
-nfcDemoApp_FLAGS = -I$(srcdir)/demoapp -I$(srcdir)/src/include
+readNfc_FLAGS = -I$(srcdir)/demoapp -I$(srcdir)/src/include
AM_CPPFLAGS = \
-I$(srcdir)/src/include \
$(INCLUDE_PARAMS) \
$(libnfc_nci_linux_la_FLAGS) \
- $(nfcDemoApp_FLAGS)
+ $(readNfc_FLAGS)
if LLCP1_3
AM_CPPFLAGS += \
## -177,7 +177,7 ##
src/service/linux_nfc_api.c \
src/service/linux_nfc_factory_api.c
-nfcDemoApp_SOURCES := \
+readNfc_SOURCES := \
demoapp/main.c \
demoapp/tools.c
## -231,6 +231,6 ##
libnfc_nci_linux_la_LDFLAGS +=-DPN551C2=3
libnfc_nci_linux_la_LDFLAGS += -shared -pthread -ldl -lrt -fPIC -release 1 -versionnfo 0:0:0
-nfcDemoApp_LDFLAGS = -pthread -ldl -lrt -lnfc_nci_linux
+readNfc_LDFLAGS = -pthread -ldl -lrt -lnfc_nci_linux
Thus I want to apply a patch from local to github fetched code. But whenever I try to bitbake apply patch I always get the following error:
can't find file to patch at input line 3

Answer 1

The problem is how you created your patch. The easiest way (if you're used to git) is to use git. Otherwise, diffing two complete source trees is a good and easy way.
One way to solve your issue would be to add ;striplevel=0 to the SRC_URI line. (A strip level of 1 is assumed by bitbake / OE).
Another way would be to modify your patch to start with:
--- a/Makefile.am
+++ b/Makefile.am
That should solve your problem.