diff --git a/drivers/nand/nand.c b/drivers/nand/nand.c index f79f7c3..0a6128c 100644 --- a/drivers/nand/nand.c +++ b/drivers/nand/nand.c @@ -50,11 +50,22 @@ #define NOTALIGNED(x) (x & (info->writesize - 1)) != 0 +static int all_ff(const void *buf, int len) +{ + int i; + const uint8_t *p = buf; + + for (i = 0; i < len; i++) + if (p[i] != 0xFF) + return 0; + return 1; +} + static ssize_t nand_write(struct cdev* cdev, const void *buf, size_t _count, ulong offset, ulong flags) { struct mtd_info *info = cdev->priv; size_t retlen, now; - int ret; + int ret = 0; void *wrbuf = NULL; size_t count = _count; @@ -73,9 +84,13 @@ wrbuf = xmalloc(info->writesize); memset(wrbuf, 0xff, info->writesize); memcpy(wrbuf + (offset % info->writesize), buf, now); - ret = info->write(info, offset & ~(info->writesize - 1), info->writesize, &retlen, wrbuf); + if (!all_ff(wrbuf, info->writesize)) + ret = info->write(info, offset & ~(info->writesize - 1), + info->writesize, &retlen, wrbuf); + free(wrbuf); } else { - ret = info->write(info, offset, now, &retlen, buf); + if (!all_ff(buf, info->writesize)) + ret = info->write(info, offset, now, &retlen, buf); debug("offset: 0x%08x now: 0x%08x retlen: 0x%08x\n", offset, now, retlen); } if (ret) @@ -87,9 +102,6 @@ } out: - if (wrbuf) - free(wrbuf); - return ret ? ret : _count; }