kernel-module-split: Allow for external conf files

Some recipes might provide conf files produced during build phase or
simply tracked in the VCS instead of generating them with Yocto.
In such cases those conf files wouldn't be assigned to correct packages.
With this change, if user wants to generate a conf file they still can,
but not generating them won't prevent assigning the file to proper
package given the file exists.

(From OE-Core rev: c7faf141592d1e2a5cab32a83f7e1498ee498d65)

Signed-off-by: Michal Sieron <michalwsieron@gmail.com>
Signed-off-by: Mathieu Dubois-Briand <mathieu.dubois-briand@bootlin.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

Author: michalsieron

meta/classes-recipe/kernel-module-split.bbclass

@@ -99,16 +99,22 @@ python split_kernel_module_packages () {
             bb.warn("module_autoload_%s was replaced by KERNEL_MODULE_AUTOLOAD for cases where basename == module name, please drop it" % basename)
         if autoload and basename not in autoloadlist:
             bb.warn("module_autoload_%s is defined but '%s' isn't included in KERNEL_MODULE_AUTOLOAD, please add it there" % (basename, basename))
+
+        # The .conf file can either be installed by a recipe or generated from module_autoload_*
+        conf = '%s/%s.conf' % (d.getVar('modulesloaddir'), basename)
+        name = '%s%s' % (dvar, conf)
+        # If module name is in KERNEL_MODULE_AUTOLOAD, then generate the .conf file and write to `name`.
         if basename in autoloadlist:
-            conf = '%s/%s.conf' % (d.getVar('modulesloaddir'), basename)
-            name = '%s%s' % (dvar, conf)
             os.makedirs(os.path.dirname(name), exist_ok=True)
             with open(name, 'w') as f:
                 if autoload:
                     for m in autoload.split():
                         f.write('%s\n' % m)
                 else:
                     f.write('%s\n' % basename)
+        # If the .conf file exits, then add it to FILES:* and CONFFILES:* and add postinstall hook.
+        # It doesn't matter if it was generated from module_autoload_* or installed by the recipe.
+        if os.path.exists(name):
             conf2append = ' %s' % conf
             d.appendVar('FILES:%s' % pkg, conf2append)
             d.appendVar('CONFFILES:%s' % pkg, conf2append)
@@ -121,19 +127,24 @@ python split_kernel_module_packages () {
         # Write out any modconf fragment
         modconflist = (d.getVar("KERNEL_MODULE_PROBECONF") or "").split()
         modconf = d.getVar('module_conf_%s' % basename)
+
+        # The .conf file can either be installed by a recipe or generated from module_conf_*
+        conf = '%s/%s.conf' % (d.getVar('modprobedir'), basename)
+        name = '%s%s' % (dvar, conf)
+        # If module name is in KERNEL_MODULE_PROBECONF, then generate the .conf file and write to `name`.
         if modconf and basename in modconflist:
-            conf = '%s/%s.conf' % (d.getVar('modprobedir'), basename)
-            name = '%s%s' % (dvar, conf)
             os.makedirs(os.path.dirname(name), exist_ok=True)
             with open(name, 'w') as f:
                 f.write("%s\n" % modconf)
+        elif modconf:
+            bb.error("Please ensure module %s is listed in KERNEL_MODULE_PROBECONF since module_conf_%s is set" % (basename, basename))
+        # If the .conf file exits, then add it to FILES:* and CONFFILES:*.
+        # It doesn't matter if it was generated from module_conf_* or installed by the recipe.
+        if os.path.exists(name):
             conf2append = ' %s' % conf
             d.appendVar('FILES:%s' % pkg, conf2append)
             d.appendVar('CONFFILES:%s' % pkg, conf2append)
 
-        elif modconf:
-            bb.error("Please ensure module %s is listed in KERNEL_MODULE_PROBECONF since module_conf_%s is set" % (basename, basename))
-
         if "description" in vals:
             old_desc = d.getVar('DESCRIPTION:' + pkg) or ""
             d.setVar('DESCRIPTION:' + pkg, old_desc + "; " + vals["description"])