mtd: nand: reintroduce NAND_NO_READRDY as NAND_NEED_READRDY

This partially reverts commit 1696e6bc2ae83734e64e206ac99766ea19e9a14e
("mtd: nand: kill NAND_NO_READRDY").

In that patch I overlooked a few things.

The original documentation for NAND_NO_READRDY included "True for all
large page devices, as they do not support autoincrement." I was
conflating "not support autoincrement" with the NAND_NO_AUTOINCR option,
which was in fact doing nothing. So, when I dropped NAND_NO_AUTOINCR, I
concluded that I then could harmlessly drop NAND_NO_READRDY. But of
course the fact the NAND_NO_AUTOINCR was doing nothing didn't mean
NAND_NO_READRDY was doing nothing...

So, NAND_NO_READRDY is re-introduced as NAND_NEED_READRDY and applied
only to those few remaining small-page NAND which needed it in the first
place.

Cc: stable@kernel.org [3.5+]
Reported-by: Alexander Shiyan <shc_work@mail.ru>
Tested-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

1 files changed, 16 insertions, 0 deletions

diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c
index 43214151b882..42c63927609d 100644
--- a/drivers/mtd/nand/nand_base.c
+++ b/drivers/mtd/nand/nand_base.c
@@ -1523,6 +1523,14 @@ static int nand_do_read_ops(struct mtd_info *mtd, loff_t from,
                                         oobreadlen -= toread;
                                 }
                         }
+
+                        if (chip->options & NAND_NEED_READRDY) {
+                                /* Apply delay or wait for ready/busy pin */
+                                if (!chip->dev_ready)
+                                        udelay(chip->chip_delay);
+                                else
+                                        nand_wait_ready(mtd);
+                        }
                 } else {
                         memcpy(buf, chip->buffers->databuf + col, bytes);
                         buf += bytes;
@@ -1787,6 +1795,14 @@ static int nand_do_read_oob(struct mtd_info *mtd, loff_t from,
                 len = min(len, readlen);
                 buf = nand_transfer_oob(chip, buf, ops, len);
 
+                if (chip->options & NAND_NEED_READRDY) {
+                        /* Apply delay or wait for ready/busy pin */
+                        if (!chip->dev_ready)
+                                udelay(chip->chip_delay);
+                        else
+                                nand_wait_ready(mtd);
+                }
+
                 readlen -= len;
                 if (!readlen)
                         break;