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authorJoe Hershberger <joe.hershberger@ni.com>2012-08-17 15:36:40 -0500
committerStefan Roese <sr@denx.de>2012-09-03 11:24:27 +0200
commit6822a647b94cb05869231251e5a29f9742bb3ce2 (patch)
tree0232758ddb50f2f8c75d467de0a049e85283a8b4 /drivers/mtd
parenta005f19eff946454985785788c344f10616d571e (diff)
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cfi: Check for blank before erase
Added an optional check in the CFI driver to evaluate if the sector is already blank before issuing an erase command. Improves erase time by over a factor of 10 if already blank. Signed-off-by: Joe Hershberger <joe.hershberger@ni.com> Signed-off-by: Stefan Roese <sr@denx.de>
Diffstat (limited to 'drivers/mtd')
-rw-r--r--drivers/mtd/cfi_flash.c26
1 files changed, 26 insertions, 0 deletions
diff --git a/drivers/mtd/cfi_flash.c b/drivers/mtd/cfi_flash.c
index f0f301a..97a4fd7 100644
--- a/drivers/mtd/cfi_flash.c
+++ b/drivers/mtd/cfi_flash.c
@@ -1078,6 +1078,32 @@ int flash_erase (flash_info_t * info, int s_first, int s_last)
for (sect = s_first; sect <= s_last; sect++) {
if (info->protect[sect] == 0) { /* not protected */
+#ifdef CONFIG_SYS_FLASH_CHECK_BLANK_BEFORE_ERASE
+ int k;
+ int size;
+ int erased;
+ u32 *flash;
+
+ /*
+ * Check if whole sector is erased
+ */
+ size = flash_sector_size(info, sect);
+ erased = 1;
+ flash = (u32 *)info->start[sect];
+ /* divide by 4 for longword access */
+ size = size >> 2;
+ for (k = 0; k < size; k++) {
+ if (flash_read32(flash++) != 0xffffffff) {
+ erased = 0;
+ break;
+ }
+ }
+ if (erased) {
+ if (flash_verbose)
+ putc(',');
+ continue;
+ }
+#endif
switch (info->vendor) {
case CFI_CMDSET_INTEL_PROG_REGIONS:
case CFI_CMDSET_INTEL_STANDARD: