[MTD] m25p80: chip erase != block erase != sector erase

This fixes broken terminology added in the "m25p80.c erase enhance" patch,
which added a chip erase command but called it "block erase".  There are
already two block erase commands; blocks are 4KiB or 32KiB.  There's also
a sector erase (usually 64 KiB).  Chip erase typically covers Megabytes.

  OPCODE_BE   ==> OPCODE_CHIP_ERASE
  erase_block ==> erase_chip

[dbrownell@users.sourceforge.net: update sector erase comments too ]

Signed-off-by: Chen Gong <clumsycg@gmail.com>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

1 files changed, 13 insertions, 10 deletions

diff --git a/drivers/mtd/devices/m25p80.c b/drivers/mtd/devices/m25p80.c
index 6188fd4ddcc..6659b2275c0 100644
--- a/drivers/mtd/devices/m25p80.c
+++ b/drivers/mtd/devices/m25p80.c
@@ -37,9 +37,9 @@
 #define OPCODE_NORM_READ        0x03    /* Read data bytes (low frequency) */
 #define OPCODE_FAST_READ        0x0b    /* Read data bytes (high frequency) */
 #define OPCODE_PP               0x02    /* Page program (up to 256 bytes) */
-#define OPCODE_BE_4K            0x20    /* Erase 4KiB block */
+#define OPCODE_BE_4K            0x20    /* Erase 4KiB block */
 #define OPCODE_BE_32K           0x52    /* Erase 32KiB block */
-#define OPCODE_BE               0xc7    /* Erase whole flash block */
+#define OPCODE_CHIP_ERASE       0xc7    /* Erase whole flash chip */
 #define OPCODE_SE               0xd8    /* Sector erase (usually 64KiB) */
 #define OPCODE_RDID             0x9f    /* Read JEDEC ID */
 
@@ -167,7 +167,7 @@ static int wait_till_ready(struct m25p *flash)
  *
  * Returns 0 if successful, non-zero otherwise.
  */
-static int erase_block(struct m25p *flash)
+static int erase_chip(struct m25p *flash)
 {
         DEBUG(MTD_DEBUG_LEVEL3, "%s: %s %dKiB\n",
                         flash->spi->dev.bus_id, __func__,
@@ -181,7 +181,7 @@ static int erase_block(struct m25p *flash)
         write_enable(flash);
 
         /* Set up command buffer. */
-        flash->command[0] = OPCODE_BE;
+        flash->command[0] = OPCODE_CHIP_ERASE;
 
         spi_write(flash->spi, flash->command, 1);
 
@@ -250,15 +250,18 @@ static int m25p80_erase(struct mtd_info *mtd, struct erase_info *instr)
 
         mutex_lock(&flash->lock);
 
-        /* REVISIT in some cases we could speed up erasing large regions
-         * by using OPCODE_SE instead of OPCODE_BE_4K
-         */
-
-        /* now erase those sectors */
-        if (len == flash->mtd.size && erase_block(flash)) {
+        /* whole-chip erase? */
+        if (len == flash->mtd.size && erase_chip(flash)) {
                 instr->state = MTD_ERASE_FAILED;
                 mutex_unlock(&flash->lock);
                 return -EIO;
+
+        /* REVISIT in some cases we could speed up erasing large regions
+         * by using OPCODE_SE instead of OPCODE_BE_4K.  We may have set up
+         * to use "small sector erase", but that's not always optimal.
+         */
+
+        /* "sector"-at-a-time erase */
         } else {
                 while (len) {
                         if (erase_sector(flash, addr)) {