[PATCH][CFI] Wrong cache invalidation bug fix

[massimo cirillo]

OK, I've verified your suggestion and the tests are ok.
Following the overall patch for the cfi_cmdset_0001.c

Signed-off-by Massimo Cirillo <maxcir at gmail.com> and Giuseppe D'Eliseo
<giuseppedeliseo at gmail.com>
Acked-by: Nicolas Pitre <nico at cam.org> and Jörn Engel <joern at logfs.org>

------
diff -aur a/drivers/mtd/chips/cfi_cmdset_0001.c
b/drivers/mtd/chips/cfi_cmdset_0001.c

--- a/drivers/mtd/chips/cfi_cmdset_0001.c       2007-12-05
10:45:20.000000000 +0100
+++ b/drivers/mtd/chips/cfi_cmdset_0001.c       2007-11-16
19:14:27.000000000 +0100
@@ -1486,9 +1486,12 @@
       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 */
@@ -1501,7 +1504,7 @@
               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);

@@ -1592,7 +1595,7 @@
       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);
------

2007/12/3, Nicolas Pitre <nico at cam.org>:
> On Mon, 3 Dec 2007, massimo cirillo wrote:
>
> > Hi,
> >
> > We encountered the problem with cache invalidation in CFI driver. It
> > causes corruptions of data read from flash.
> >
> > The problem is investigated. 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.
> > The following patch fixes this problem. This patch has been verified
> > on our OMAP based platform.
> > Could you please acknowledge and commit this patch?
> >
> > Thanks a lot.
> >
> > Signed-off-by Massimo Cirillo <maxcir at gmail.com> and Giuseppe D'Eliseo
> > <giuseppedeliseo at gmail.com>
>
> This patch is correct.  However, to make it more obvious, please change
> the used variable in the XIP_INVAL_CACHED_RANGE() call used in the same
> function as well.
>
> With that change you can add "Acked-by: Nicolas Pitre <nico at cam.org>".
>
>
> Nicolas
>