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authorAnton Vorontsov <avorontsov@ru.mvista.com>2008-03-28 22:10:54 +0300
committerDavid Woodhouse <dwmw2@infradead.org>2008-04-22 21:13:53 +0100
commit0ff6631be150702ed4c92b46b77941affee866ba (patch)
treeefce0cfff80141c4f432d89d872d4db9d1802cbf
parent93919d384df98eba02bebd417ecb2f481b3bdcb8 (diff)
downloadlinux-0ff6631be150702ed4c92b46b77941affee866ba.tar.bz2
[MTD] [NAND] fsl_elbc_nand: workaround for hangs during nand write
Using current driver elbc sometimes hangs during nand write. Reading back last byte helps though (thanks to Scott Wood for the idea). Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com> Acked-by: Scott Wood <scottwood@freescale.com> Signed-off-by: David Woodhouse <dwmw2@infradead.org>
-rw-r--r--drivers/mtd/nand/fsl_elbc_nand.c11
1 files changed, 10 insertions, 1 deletions
diff --git a/drivers/mtd/nand/fsl_elbc_nand.c b/drivers/mtd/nand/fsl_elbc_nand.c
index 919c192b8f27..4b69aacdf5ca 100644
--- a/drivers/mtd/nand/fsl_elbc_nand.c
+++ b/drivers/mtd/nand/fsl_elbc_nand.c
@@ -481,7 +481,7 @@ static void fsl_elbc_write_buf(struct mtd_info *mtd, const u8 *buf, int len)
struct fsl_elbc_ctrl *ctrl = priv->ctrl;
unsigned int bufsize = mtd->writesize + mtd->oobsize;
- if (len < 0) {
+ if (len <= 0) {
dev_err(ctrl->dev, "write_buf of %d bytes", len);
ctrl->status = 0;
return;
@@ -496,6 +496,15 @@ static void fsl_elbc_write_buf(struct mtd_info *mtd, const u8 *buf, int len)
}
memcpy_toio(&ctrl->addr[ctrl->index], buf, len);
+ /*
+ * This is workaround for the weird elbc hangs during nand write,
+ * Scott Wood says: "...perhaps difference in how long it takes a
+ * write to make it through the localbus compared to a write to IMMR
+ * is causing problems, and sync isn't helping for some reason."
+ * Reading back the last byte helps though.
+ */
+ in_8(&ctrl->addr[ctrl->index] + len - 1);
+
ctrl->index += len;
}