mtd: bcm47xxpart: improve probing of nvram partition
authorHauke Mehrtens <hauke@hauke-m.de>
Thu, 24 Jan 2013 18:03:37 +0000 (19:03 +0100)
committerArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Mon, 4 Feb 2013 08:31:36 +0000 (10:31 +0200)
The nvram in the nvram partition does not start at the beginning of the
partition on every device. Sometimes they are stating in the middle of
a partition or the first 0x1000 bytes are free.

Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
drivers/mtd/bcm47xxpart.c

index 986ab6e..9bcec8f 100644 (file)
 /* 10 parts were found on sflash on Netgear WNDR4500 */
 #define BCM47XXPART_MAX_PARTS          12
 
-/*
- * Amount of bytes we read when analyzing each block of flash memory.
- * Set it big enough to allow detecting partition and reading important data.
- */
-#define BCM47XXPART_BYTES_TO_READ      0x404
-
 /* Magics */
 #define BOARD_DATA_MAGIC               0x5246504D      /* MPFR */
 #define POT_MAGIC1                     0x54544f50      /* POTT */
@@ -63,14 +57,17 @@ static int bcm47xxpart_parse(struct mtd_info *master,
        struct trx_header *trx;
        int trx_part = -1;
        int last_trx_part = -1;
+       int max_bytes_to_read = 0x8004;
 
        if (blocksize <= 0x10000)
                blocksize = 0x10000;
+       if (blocksize == 0x20000)
+               max_bytes_to_read = 0x18004;
 
        /* Alloc */
        parts = kzalloc(sizeof(struct mtd_partition) * BCM47XXPART_MAX_PARTS,
                        GFP_KERNEL);
-       buf = kzalloc(BCM47XXPART_BYTES_TO_READ, GFP_KERNEL);
+       buf = kzalloc(max_bytes_to_read, GFP_KERNEL);
 
        /* Parse block by block looking for magics */
        for (offset = 0; offset <= master->size - blocksize;
@@ -85,7 +82,7 @@ static int bcm47xxpart_parse(struct mtd_info *master,
                }
 
                /* Read beginning of the block */
-               if (mtd_read(master, offset, BCM47XXPART_BYTES_TO_READ,
+               if (mtd_read(master, offset, max_bytes_to_read,
                             &bytes_read, (uint8_t *)buf) < 0) {
                        pr_err("mtd_read error while parsing (offset: 0x%X)!\n",
                               offset);
@@ -100,9 +97,16 @@ static int bcm47xxpart_parse(struct mtd_info *master,
                }
 
                /* Standard NVRAM */
-               if (buf[0x000 / 4] == NVRAM_HEADER) {
+               if (buf[0x000 / 4] == NVRAM_HEADER ||
+                   buf[0x1000 / 4] == NVRAM_HEADER ||
+                   buf[0x8000 / 4] == NVRAM_HEADER ||
+                   (blocksize == 0x20000 && (
+                     buf[0x10000 / 4] == NVRAM_HEADER ||
+                     buf[0x11000 / 4] == NVRAM_HEADER ||
+                     buf[0x18000 / 4] == NVRAM_HEADER))) {
                        bcm47xxpart_add_part(&parts[curr_part++], "nvram",
                                             offset, 0);
+                       offset = rounddown(offset, blocksize);
                        continue;
                }