From 097f2576eb7dbc8cd5f610847f229f4fea305b80 Mon Sep 17 00:00:00 2001 From: Andy Lowe Date: Fri, 12 Jan 2007 18:05:10 -0500 Subject: [PATCH] [MTD] fix CFI point method for discontiguous maps The CFI probe routine is capable of detecting flash banks consisting of identical chips mapped to physically discontiguous addresses. (One common way this can occur is if a flash bank is populated with chips of less capacity than the hardware was designed to support.) The CFI point() routine currently ignores any such gaps. This patch fixes the CFI point() routine so that it truncates any request that would span a gap. Signed-off-by: Andy Lowe Signed-off-by: Nicolas Pitre Signed-off-by: David Woodhouse --- drivers/mtd/chips/cfi_cmdset_0001.c | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-) diff --git a/drivers/mtd/chips/cfi_cmdset_0001.c b/drivers/mtd/chips/cfi_cmdset_0001.c index 39eff9ff575c..c655e971c158 100644 --- a/drivers/mtd/chips/cfi_cmdset_0001.c +++ b/drivers/mtd/chips/cfi_cmdset_0001.c @@ -1166,28 +1166,34 @@ static int cfi_intelext_point (struct mtd_info *mtd, loff_t from, size_t len, si { struct map_info *map = mtd->priv; struct cfi_private *cfi = map->fldrv_priv; - unsigned long ofs; + unsigned long ofs, last_end = 0; int chipnum; int ret = 0; if (!map->virt || (from + len > mtd->size)) return -EINVAL; - *mtdbuf = (void *)map->virt + from; - *retlen = 0; - /* Now lock the chip(s) to POINT state */ /* ofs: offset within the first chip that the first read should start */ chipnum = (from >> cfi->chipshift); ofs = from - (chipnum << cfi->chipshift); + *mtdbuf = (void *)map->virt + cfi->chips[chipnum].start + ofs; + *retlen = 0; + while (len) { unsigned long thislen; if (chipnum >= cfi->numchips) break; + /* We cannot point across chips that are virtually disjoint */ + if (!last_end) + last_end = cfi->chips[chipnum].start; + else if (cfi->chips[chipnum].start != last_end) + break; + if ((len + ofs -1) >> cfi->chipshift) thislen = (1<chipshift) - ofs; else @@ -1201,6 +1207,7 @@ static int cfi_intelext_point (struct mtd_info *mtd, loff_t from, size_t len, si len -= thislen; ofs = 0; + last_end += 1 << cfi->chipshift; chipnum++; } return 0; -- 2.30.2