@@ -436,6 +436,24 @@ static int check_skip_len(nand_info_t *nand, loff_t offset, size_t length)
return ret;
}
+#ifdef CONFIG_CMD_NAND_TRIMFFS
+static size_t drop_ffs(const nand_info_t *nand, const u_char *buf,
+ const size_t *len)
+{
+ size_t i, l = *len;
+
+ for (i = l - 1; i >= 0; i--)
+ if (((const uint8_t *)buf)[i] != 0xFF)
+ break;
+
+ /* The resulting length must be aligned to the minimum flash I/O size */
+ l = i + 1;
+ l = (l + nand->writesize - 1) / nand->writesize;
+ l *= nand->writesize;
+ return l;
+}
+#endif
+
/**
* nand_write_skip_bad:
*
@@ -499,7 +517,7 @@ int nand_write_skip_bad(nand_info_t *nand, loff_t offset, size_t *length,
return -EINVAL;
}
- if (!need_skip) {
+ if (!need_skip && !(flags & WITH_DROP_FFS)) {
rval = nand_write (nand, offset, length, buffer);
if (rval == 0)
return 0;
@@ -512,7 +530,7 @@ int nand_write_skip_bad(nand_info_t *nand, loff_t offset, size_t *length,
while (left_to_write > 0) {
size_t block_offset = offset & (nand->erasesize - 1);
- size_t write_size;
+ size_t write_size, truncated_write_size;
WATCHDOG_RESET ();
@@ -558,7 +576,15 @@ int nand_write_skip_bad(nand_info_t *nand, loff_t offset, size_t *length,
else
#endif
{
- rval = nand_write (nand, offset, &write_size, p_buffer);
+ truncated_write_size = write_size;
+#ifdef CONFIG_CMD_NAND_TRIMFFS
+ if (flags & WITH_DROP_FFS)
+ truncated_write_size = drop_ffs(nand, p_buffer,
+ &write_size);
+#endif
+
+ rval = nand_write(nand, offset, &truncated_write_size,
+ p_buffer);
offset += write_size;
p_buffer += write_size;
}
@@ -116,6 +116,7 @@ int nand_read_skip_bad(nand_info_t *nand, loff_t offset, size_t *length,
u_char *buffer);
#define WITH_YAFFS_OOB (1 << 0) /* whether write with yaffs format */
+#define WITH_DROP_FFS (1 << 1) /* drop trailing all-0xff pages */
#define WITH_DEFAULTS 0
int nand_write_skip_bad(nand_info_t *nand, loff_t offset, size_t *length,
Add a flag to nand_read_skip_bad() such that if true, any trailing pages in an eraseblock whose contents are entirely 0xff will be dropped. The implementation is via a new drop_ffs() function which is based on the function of the same name from the ubiformat utility by Artem Bityutskiy. This is as-per the reccomendations of the UBI FAQ [1] Signed-off-by: Ben Gardiner <bengardiner@nanometrics.ca> CC: Artem Bityutskiy <dedekind1@gmail.com> [1] http://www.linux-mtd.infradead.org/doc/ubi.html#L_flasher_algo --- This behaviour was found to fix both UBI and JFFS2 images written to cleanly erased NAND partitions on da850evm. Changes since v1: * rebased to HEAD of git://git.denx.de/u-boot-nand-flash.git : ff7b4a0 ("env_nand: zero-initialize variable nand_erase_options") * wrap the new functionality in a CONFIG_CMD_NAND_TRIMFFS ifdef to reduce size impact of new feature --- drivers/mtd/nand/nand_util.c | 32 +++++++++++++++++++++++++++++--- include/nand.h | 1 + 2 files changed, 30 insertions(+), 3 deletions(-)