1 files changed, 42 insertions, 18 deletions

diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c
index e5718e5ecf92..3bde96a3f7bf 100644
--- a/drivers/mtd/nand/nand_base.c
+++ b/drivers/mtd/nand/nand_base.c
@@ -1095,10 +1095,11 @@ static void nand_release_data_interface(struct nand_chip *chip)
 /**
  * nand_reset - Reset and initialize a NAND device
  * @chip: The NAND chip
+ * @chipnr: Internal die id
  *
  * Returns 0 for success or negative error code otherwise
  */
-int nand_reset(struct nand_chip *chip)
+int nand_reset(struct nand_chip *chip, int chipnr)
 {
         struct mtd_info *mtd = nand_to_mtd(chip);
         int ret;
@@ -1107,9 +1108,17 @@ int nand_reset(struct nand_chip *chip)
         if (ret)
                 return ret;
 
+        /*
+         * The CS line has to be released before we can apply the new NAND
+         * interface settings, hence this weird ->select_chip() dance.
+         */
+        chip->select_chip(mtd, chipnr);
         chip->cmdfunc(mtd, NAND_CMD_RESET, -1, -1);
+        chip->select_chip(mtd, -1);
 
+        chip->select_chip(mtd, chipnr);
         ret = nand_setup_data_interface(chip);
+        chip->select_chip(mtd, -1);
         if (ret)
                 return ret;
 
@@ -1185,8 +1194,6 @@ int nand_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
         /* Shift to get chip number */
         chipnr = ofs >> chip->chip_shift;
 
-        chip->select_chip(mtd, chipnr);
-
         /*
          * Reset the chip.
          * If we want to check the WP through READ STATUS and check the bit 7
@@ -1194,7 +1201,9 @@ int nand_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
          * some operation can also clear the bit 7 of status register
          * eg. erase/program a locked block
          */
-        nand_reset(chip);
+        nand_reset(chip, chipnr);
+
+        chip->select_chip(mtd, chipnr);
 
         /* Check, if it is write protected */
         if (nand_check_wp(mtd)) {
@@ -1244,8 +1253,6 @@ int nand_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
         /* Shift to get chip number */
         chipnr = ofs >> chip->chip_shift;
 
-        chip->select_chip(mtd, chipnr);
-
         /*
          * Reset the chip.
          * If we want to check the WP through READ STATUS and check the bit 7
@@ -1253,7 +1260,9 @@ int nand_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
          * some operation can also clear the bit 7 of status register
          * eg. erase/program a locked block
          */
-        nand_reset(chip);
+        nand_reset(chip, chipnr);
+
+        chip->select_chip(mtd, chipnr);
 
         /* Check, if it is write protected */
         if (nand_check_wp(mtd)) {
@@ -2940,10 +2949,6 @@ static int nand_do_write_oob(struct mtd_info *mtd, loff_t to,
         }
 
         chipnr = (int)(to >> chip->chip_shift);
-        chip->select_chip(mtd, chipnr);
-
-        /* Shift to get page */
-        page = (int)(to >> chip->page_shift);
 
         /*
          * Reset the chip. Some chips (like the Toshiba TC5832DC found in one
@@ -2951,7 +2956,12 @@ static int nand_do_write_oob(struct mtd_info *mtd, loff_t to,
          * if we don't do this. I have no clue why, but I seem to have 'fixed'
          * it in the doc2000 driver in August 1999.  dwmw2.
          */
-        nand_reset(chip);
+        nand_reset(chip, chipnr);
+
+        chip->select_chip(mtd, chipnr);
+
+        /* Shift to get page */
+        page = (int)(to >> chip->page_shift);
 
         /* Check, if it is write protected */
         if (nand_check_wp(mtd)) {
@@ -3984,14 +3994,14 @@ static struct nand_flash_dev *nand_get_flash_type(struct mtd_info *mtd,
         int i, maf_idx;
         u8 id_data[8];
 
-        /* Select the device */
-        chip->select_chip(mtd, 0);
-
         /*
          * Reset the chip, required by some chips (e.g. Micron MT29FxGxxxxx)
          * after power-up.
          */
-        nand_reset(chip);
+        nand_reset(chip, 0);
+
+        /* Select the device */
+        chip->select_chip(mtd, 0);
 
         /* Send the command for reading device ID */
         chip->cmdfunc(mtd, NAND_CMD_READID, 0x00, -1);
@@ -4329,17 +4339,31 @@ int nand_scan_ident(struct mtd_info *mtd, int maxchips,
                 return PTR_ERR(type);
         }
 
+        /* Initialize the ->data_interface field. */
         ret = nand_init_data_interface(chip);
         if (ret)
                 return ret;
 
+        /*
+         * Setup the data interface correctly on the chip and controller side.
+         * This explicit call to nand_setup_data_interface() is only required
+         * for the first die, because nand_reset() has been called before
+         * ->data_interface and ->default_onfi_timing_mode were set.
+         * For the other dies, nand_reset() will automatically switch to the
+         * best mode for us.
+         */
+        ret = nand_setup_data_interface(chip);
+        if (ret)
+                return ret;
+
         chip->select_chip(mtd, -1);
 
         /* Check for a chip array */
         for (i = 1; i < maxchips; i++) {
-                chip->select_chip(mtd, i);
                 /* See comment in nand_get_flash_type for reset */
-                nand_reset(chip);
+                nand_reset(chip, i);
+
+                chip->select_chip(mtd, i);
                 /* Send the command for reading device ID */
                 chip->cmdfunc(mtd, NAND_CMD_READID, 0x00, -1);
                 /* Read manufacturer and device IDs */