[PATCH] Fix Oops with Atmel SPI

From: Anders Larsen
Date: Tue Apr 13 2010 - 07:32:15 EST


Tweak MTD's cache allocation to make it work with the atmel DMA'ed SPI.
Substitute kmalloc for vmalloc so the cache buffer is mappable as per
the Atmel SPI driver's requirements, otherwise an Oops would occur.

The original patch by Ian McDonnell <ian@xxxxxxxxxxxxxxxxx> was found here:
http://lists.infradead.org/pipermail/linux-mtd/2007-December/020184.html

Signed-off-by: Anders Larsen <al@xxxxxxxxxxx>
Cc: Ian McDonnell <ian@xxxxxxxxxxxxxxxxx>
Cc: David Woodhouse <dwmw2@xxxxxxxxxxxxx>
Cc: Matthias Kaehlcke <matthias@xxxxxxxxxxxx>
Cc: Artem Bityutskiy <Artem.Bityutskiy@xxxxxxxxx>
Cc: Nicolas Pitre <nico@xxxxxxxxxxx>
---
drivers/mtd/mtdblock.c | 8 ++++++++
1 file changed, 8 insertions(+)

Index: b/drivers/mtd/mtdblock.c
===================================================================
--- a/drivers/mtd/mtdblock.c
+++ b/drivers/mtd/mtdblock.c
@@ -253,7 +253,11 @@ static int mtdblock_writesect(struct mtd
{
struct mtdblk_dev *mtdblk = mtdblks[dev->devnum];
if (unlikely(!mtdblk->cache_data && mtdblk->cache_size)) {
+#ifdef CONFIG_SPI_ATMEL
+ mtdblk->cache_data = kmalloc(mtdblk->mtd->erasesize, GFP_KERNEL);
+#else
mtdblk->cache_data = vmalloc(mtdblk->mtd->erasesize);
+#endif
if (!mtdblk->cache_data)
return -EINTR;
/* -EINTR is not really correct, but it is the best match
@@ -322,7 +326,11 @@ static int mtdblock_release(struct mtd_b
mtdblks[dev] = NULL;
if (mtdblk->mtd->sync)
mtdblk->mtd->sync(mtdblk->mtd);
+#ifdef CONFIG_SPI_ATMEL
+ kfree(mtdblk->cache_data);
+#else
vfree(mtdblk->cache_data);
+#endif
kfree(mtdblk);
}


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