Merge tag 'for-linus-20150216' of git://git.infradead.org/linux-mtd

[mirror_ubuntu-bionic-kernel.git] / drivers / mtd / mtdcore.c

diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c
index 0ec4d6ea1e4b8d7729a2299702391ab3f504e914..11883bd26d9d35e8234cc7dc74f51b7ed57d7566 100644 (file)
--- a/drivers/mtd/mtdcore.c
+++ b/drivers/mtd/mtdcore.c
@@ -37,6 +37,7 @@
 #include <linux/backing-dev.h>
 #include <linux/gfp.h>
 #include <linux/slab.h>
+#include <linux/reboot.h>
 
 #include <linux/mtd/mtd.h>
 #include <linux/mtd/partitions.h>
@@ -356,6 +357,17 @@ unsigned mtd_mmap_capabilities(struct mtd_info *mtd)
 EXPORT_SYMBOL_GPL(mtd_mmap_capabilities);
 #endif
 
+static int mtd_reboot_notifier(struct notifier_block *n, unsigned long state,
+                              void *cmd)
+{
+       struct mtd_info *mtd;
+
+       mtd = container_of(n, struct mtd_info, reboot_notifier);
+       mtd->_reboot(mtd);
+
+       return NOTIFY_DONE;
+}
+
 /**
  *     add_mtd_device - register an MTD device
  *     @mtd: pointer to new MTD device info structure
@@ -544,6 +556,19 @@ int mtd_device_parse_register(struct mtd_info *mtd, const char * const *types,
                        err = -ENODEV;
        }
 
+       /*
+        * FIXME: some drivers unfortunately call this function more than once.
+        * So we have to check if we've already assigned the reboot notifier.
+        *
+        * Generally, we can make multiple calls work for most cases, but it
+        * does cause problems with parse_mtd_partitions() above (e.g.,
+        * cmdlineparts will register partitions more than once).
+        */
+       if (mtd->_reboot && !mtd->reboot_notifier.notifier_call) {
+               mtd->reboot_notifier.notifier_call = mtd_reboot_notifier;
+               register_reboot_notifier(&mtd->reboot_notifier);
+       }
+
        return err;
 }
 EXPORT_SYMBOL_GPL(mtd_device_parse_register);
@@ -558,6 +583,9 @@ int mtd_device_unregister(struct mtd_info *master)
 {
        int err;
 
+       if (master->_reboot)
+               unregister_reboot_notifier(&master->reboot_notifier);
+
        err = del_mtd_partitions(master);
        if (err)
                return err;