rfkill: allocate static minor

udev has a feature of creating /dev/<node> device-nodes if it finds
a devnode:<node> modalias. This allows for auto-loading of modules that
provide the node. This requires to use a statically allocated minor
number for misc character devices.

However, rfkill uses dynamic minor numbers and prevents auto-loading
of the module. So allocate the next static misc minor number and use
it for rfkill.

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Link: https://lore.kernel.org/r/20191024174042.19851-1-marcel@holtmann.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/include/linux/miscdevice.h b/include/linux/miscdevice.h
index 3247a3d..b06b757 100644 (file)
--- a/include/linux/miscdevice.h
+++ b/include/linux/miscdevice.h
@@ -57,6 +57,7 @@
 #define UHID_MINOR             239
 #define USERIO_MINOR           240
 #define VHOST_VSOCK_MINOR      241
+#define RFKILL_MINOR           242
 #define MISC_DYNAMIC_MINOR     255
 
 struct device;

diff --git a/net/rfkill/core.c b/net/rfkill/core.c
index f9b08a6..0bf9bf1 100644 (file)
--- a/net/rfkill/core.c
+++ b/net/rfkill/core.c
@@ -1316,10 +1316,12 @@ static const struct file_operations rfkill_fops = {
        .llseek         = no_llseek,
 };
 
+#define RFKILL_NAME "rfkill"
+
 static struct miscdevice rfkill_miscdev = {
-       .name   = "rfkill",
        .fops   = &rfkill_fops,
-       .minor  = MISC_DYNAMIC_MINOR,
+       .name   = RFKILL_NAME,
+       .minor  = RFKILL_MINOR,
 };
 
 static int __init rfkill_init(void)
@@ -1371,3 +1373,6 @@ static void __exit rfkill_exit(void)
        class_unregister(&rfkill_class);
 }
 module_exit(rfkill_exit);
+
+MODULE_ALIAS_MISCDEV(RFKILL_MINOR);
+MODULE_ALIAS("devname:" RFKILL_NAME);