mtd: nand: expand description of read_page method in comment header

In the absence of any formal documentation of the nand interface, I thought this
patch to the header file might be helpful.

Signed-off-by: Mike Dunn <mikedunn@newsguy.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

1 files changed, 4 insertions, 2 deletions

diff --git a/include/linux/mtd/nand.h b/include/linux/mtd/nand.h
index 8f99d3621e12..d245199ccaf3 100644
--- a/include/linux/mtd/nand.h
+++ b/include/linux/mtd/nand.h
@@ -326,8 +326,10 @@ struct nand_hw_control {
  * @read_page_raw:      function to read a raw page without ECC
  * @write_page_raw:     function to write a raw page without ECC
  * @read_page:  function to read a page according to the ECC generator
- *              requirements.
- * @read_subpage:       function to read parts of the page covered by ECC.
+ *              requirements; returns maximum number of bitflips corrected in
+ *              any single ECC step, 0 if bitflips uncorrectable, -EIO hw error
+ * @read_subpage:       function to read parts of the page covered by ECC;
+ *                      returns same as read_page()
  * @write_page: function to write a page according to the ECC generator
  *              requirements.
  * @write_oob_raw:      function to write chip OOB data without ECC