From: Anton Vorontsov Date: Fri, 28 Mar 2008 19:10:54 +0000 (+0300) Subject: [MTD] [NAND] fsl_elbc_nand: workaround for hangs during nand write X-Git-Tag: firefly_0821_release~21546^2~29 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=0ff6631be150702ed4c92b46b77941affee866ba;p=firefly-linux-kernel-4.4.55.git [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 Acked-by: Scott Wood Signed-off-by: David Woodhouse --- 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; }