[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>
diff --git a/drivers/mtd/nand/fsl_elbc_nand.c b/drivers/mtd/nand/fsl_elbc_nand.c
index 919c192..4b69aac 100644
--- a/drivers/mtd/nand/fsl_elbc_nand.c
+++ b/drivers/mtd/nand/fsl_elbc_nand.c
@@ -481,7 +481,7 @@
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 @@
}
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;
}
