UBI: introduce flash dump helper
Useful for debugging problems, compiled in only if UBI debugging
is enabled. This patch also makes the UBI writing function dump
the flash if it fails to write.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
diff --git a/drivers/mtd/ubi/debug.c b/drivers/mtd/ubi/debug.c
index 54b0186..4876977 100644
--- a/drivers/mtd/ubi/debug.c
+++ b/drivers/mtd/ubi/debug.c
@@ -196,4 +196,36 @@
printk(KERN_DEBUG "\t1st 16 characters of name: %s\n", nm);
}
+/**
+ * ubi_dbg_dump_flash - dump a region of flash.
+ * @ubi: UBI device description object
+ * @pnum: the physical eraseblock number to dump
+ * @offset: the starting offset within the physical eraseblock to dump
+ * @len: the length of the region to dump
+ */
+void ubi_dbg_dump_flash(struct ubi_device *ubi, int pnum, int offset, int len)
+{
+ int err;
+ size_t read;
+ void *buf;
+ loff_t addr = (loff_t)pnum * ubi->peb_size + offset;
+
+ buf = vmalloc(len);
+ if (!buf)
+ return;
+ err = ubi->mtd->read(ubi->mtd, addr, len, &read, buf);
+ if (err && err != -EUCLEAN) {
+ ubi_err("error %d while reading %d bytes from PEB %d:%d, "
+ "read %zd bytes", err, len, pnum, offset, read);
+ goto out;
+ }
+
+ dbg_msg("dumping %d bytes of data from PEB %d, offset %d",
+ len, pnum, offset);
+ print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET, 32, 1, buf, len, 1);
+out:
+ vfree(buf);
+ return;
+}
+
#endif /* CONFIG_MTD_UBI_DEBUG */