[MTD] Document erase interface.

Document mtd erase interface.

Signed-off-by: Jörn Engel <joern@logfs.org>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>

1 files changed, 7 insertions, 0 deletions

diff --git a/include/linux/mtd/mtd.h b/include/linux/mtd/mtd.h
index fd64ccfbce02..783fc983417c 100644
--- a/include/linux/mtd/mtd.h
+++ b/include/linux/mtd/mtd.h
@@ -133,6 +133,13 @@ struct mtd_info {
         int numeraseregions;
         struct mtd_erase_region_info *eraseregions;
 
+        /*
+         * Erase is an asynchronous operation.  Device drivers are supposed
+         * to call instr->callback() whenever the operation completes, even
+         * if it completes with a failure.
+         * Callers are supposed to pass a callback function and wait for it
+         * to be called before writing to the block.
+         */
         int (*erase) (struct mtd_info *mtd, struct erase_info *instr);
 
         /* This stuff for eXecute-In-Place */