summaryrefslogtreecommitdiff
path: root/drivers/mtd
diff options
context:
space:
mode:
authorMasahiro Yamada <yamada.masahiro@socionext.com>2017-06-13 16:45:48 +0300
committerBoris Brezillon <boris.brezillon@free-electrons.com>2017-06-20 10:14:53 +0300
commit7d370b2c255612569818134ae0a6d0e46eabfe8b (patch)
tree99e1e05b9a16623fa8f382c18340cbedb511cdc5 /drivers/mtd
parent997cde2a222091270ce0c276e567b68e5615f577 (diff)
downloadlinux-7d370b2c255612569818134ae0a6d0e46eabfe8b.tar.xz
mtd: nand: denali: use non-managed kmalloc() for DMA buffer
As Russell and Lars stated in the discussion [1], using devm_k*alloc() with DMA is not a good idea. Let's use kmalloc (not kzalloc because no need for zero-out). Also, allocate the buffer as late as possible because it must be freed for any error that follows. [1] https://lkml.org/lkml/2017/3/8/693 Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: Russell King <rmk+kernel@armlinux.org.uk> Cc: Lars-Peter Clausen <lars@metafoo.de> Acked-by: Robin Murphy <robin.murphy@arm.com> Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Diffstat (limited to 'drivers/mtd')
-rw-r--r--drivers/mtd/nand/denali.c26
1 files changed, 17 insertions, 9 deletions
diff --git a/drivers/mtd/nand/denali.c b/drivers/mtd/nand/denali.c
index ec5fc8da5f9a..bb2da2fd069e 100644
--- a/drivers/mtd/nand/denali.c
+++ b/drivers/mtd/nand/denali.c
@@ -23,6 +23,7 @@
#include <linux/mutex.h>
#include <linux/mtd/mtd.h>
#include <linux/module.h>
+#include <linux/slab.h>
#include "denali.h"
@@ -1352,13 +1353,6 @@ int denali_init(struct denali_nand_info *denali)
if (ret)
goto disable_irq;
- denali->buf = devm_kzalloc(denali->dev, mtd->writesize + mtd->oobsize,
- GFP_KERNEL);
- if (!denali->buf) {
- ret = -ENOMEM;
- goto disable_irq;
- }
-
if (ioread32(denali->flash_reg + FEATURES) & FEATURES__DMA)
denali->dma_avail = 1;
@@ -1443,17 +1437,30 @@ int denali_init(struct denali_nand_info *denali)
if (ret)
goto disable_irq;
+ /*
+ * This buffer is DMA-mapped by denali_{read,write}_page_raw. Do not
+ * use devm_kmalloc() because the memory allocated by devm_ does not
+ * guarantee DMA-safe alignment.
+ */
+ denali->buf = kmalloc(mtd->writesize + mtd->oobsize, GFP_KERNEL);
+ if (!denali->buf) {
+ ret = -ENOMEM;
+ goto disable_irq;
+ }
+
ret = nand_scan_tail(mtd);
if (ret)
- goto disable_irq;
+ goto free_buf;
ret = mtd_device_register(mtd, NULL, 0);
if (ret) {
dev_err(denali->dev, "Failed to register MTD: %d\n", ret);
- goto disable_irq;
+ goto free_buf;
}
return 0;
+free_buf:
+ kfree(denali->buf);
disable_irq:
denali_disable_irq(denali);
@@ -1467,6 +1474,7 @@ void denali_remove(struct denali_nand_info *denali)
struct mtd_info *mtd = nand_to_mtd(&denali->nand);
nand_release(mtd);
+ kfree(denali->buf);
denali_disable_irq(denali);
}
EXPORT_SYMBOL(denali_remove);