Merge tag 'pm-5.7-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael...

[mirror_ubuntu-hirsute-kernel.git] / Documentation / kbuild / kconfig-language.rst

diff --git a/Documentation/kbuild/kconfig-language.rst b/Documentation/kbuild/kconfig-language.rst
index d0111dd264105523e589dcdf95e61db923d5ccd8..a1601ec3317b49dab521f06296f9b7427f8795eb 100644 (file)
--- a/Documentation/kbuild/kconfig-language.rst
+++ b/Documentation/kbuild/kconfig-language.rst
@@ -159,11 +159,11 @@ applicable everywhere (see syntax).
   Given the following example::
 
     config FOO
-       tristate
+       tristate "foo"
        imply BAZ
 
     config BAZ
-       tristate
+       tristate "baz"
        depends on BAR
 
   The following values are possible:
@@ -173,7 +173,10 @@ applicable everywhere (see syntax).
        ===             ===             =============   ==============
        n               y               n               N/m/y
        m               y               m               M/y/n
-       y               y               y               Y/n
+       y               y               y               Y/m/n
+       n               m               n               N/m
+       m               m               m               M/n
+       y               m               n               M/n
        y               n               *               N
        ===             ===             =============   ==============
 
@@ -181,6 +184,24 @@ applicable everywhere (see syntax).
   ability to hook into a secondary subsystem while allowing the user to
   configure that subsystem out without also having to unset these drivers.
 
+  Note: If the combination of FOO=y and BAR=m causes a link error,
+  you can guard the function call with IS_REACHABLE()::
+
+       foo_init()
+       {
+               if (IS_REACHABLE(CONFIG_BAZ))
+                       baz_register(&foo);
+               ...
+       }
+
+  Note: If the feature provided by BAZ is highly desirable for FOO,
+  FOO should imply not only BAZ, but also its dependency BAR::
+
+    config FOO
+       tristate "foo"
+       imply BAR
+       imply BAZ
+
 - limiting menu display: "visible if" <expr>
 
   This attribute is only applicable to menu blocks, if the condition is