cache invalidation error for buffered write

The bug causes corruptions of data read from flash.

The original code performs cache invalidation from "adr" to "adr + len"
in do_write_buffer().  Since len and adr could be updated in the code
before invalidation - it causes improper setting of cache invalidation
regions.

Signed-off-by: Massimo Cirillo <maxcir@gmail.com>
Signed-off-by: Giuseppe D'Eliseo <giuseppedeliseo@gmail.com>
Acked-by: Nicolas Pitre <nico@cam.org>
Acked-by: Jörn Engel <joern@logfs.org>
Signed-off-by: David Woohouse <dwmw2@infradead.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 5 insertions, 2 deletions

diff --git a/drivers/mtd/chips/cfi_cmdset_0001.c b/drivers/mtd/chips/cfi_cmdset_0001.c
index a9eb1c516247..1707f98c322c 100644
--- a/drivers/mtd/chips/cfi_cmdset_0001.c
+++ b/drivers/mtd/chips/cfi_cmdset_0001.c
@@ -1504,9 +1504,12 @@ static int __xipram do_write_buffer(struct map_info *map, struct flchip *chip,
         int ret, wbufsize, word_gap, words;
         const struct kvec *vec;
         unsigned long vec_seek;
+        unsigned long initial_adr;
+        int initial_len = len;
 
         wbufsize = cfi_interleave(cfi) << cfi->cfiq->MaxBufWriteSize;
         adr += chip->start;
+        initial_adr = adr;
         cmd_adr = adr & ~(wbufsize-1);
 
         /* Let's determine this according to the interleave only once */
@@ -1519,7 +1522,7 @@ static int __xipram do_write_buffer(struct map_info *map, struct flchip *chip,
                 return ret;
         }
 
-        XIP_INVAL_CACHED_RANGE(map, adr, len);
+        XIP_INVAL_CACHED_RANGE(map, initial_adr, initial_len);
         ENABLE_VPP(map);
         xip_disable(map, chip, cmd_adr);
 
@@ -1610,7 +1613,7 @@ static int __xipram do_write_buffer(struct map_info *map, struct flchip *chip,
         chip->state = FL_WRITING;
 
         ret = INVAL_CACHE_AND_WAIT(map, chip, cmd_adr,
-                                   adr, len,
+                                   initial_adr, initial_len,
                                    chip->buffer_write_time);
         if (ret) {
                 map_write(map, CMD(0x70), cmd_adr);