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mtd: devices: m25p80: Make sure the buffer passed in op is DMA-able

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As documented in spi-mem.h, spi_mem_op->data.buf.{in,out} must be
DMA-able, and commit 4120f8d158 ("mtd: spi-nor: Use the spi_mem_xx()
API") failed to follow this rule as buffers passed to
->{read,write}_reg() are usually placed on the stack.

Fix that by allocating a scratch buffer and copying the data around.

Fixes: 4120f8d158 ("mtd: spi-nor: Use the spi_mem_xx() API")
Reported-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
Tested-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Reviewed-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
This commit is contained in:
Boris Brezillon 2018-09-17 16:31:30 +02:00
parent 85516a9881
commit 4a3e85f267
1 changed files with 23 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

26
drivers/mtd/devices/m25p80.c
View File

@ -39,13 +39,23 @@ static int m25p80_read_reg(struct spi_nor *nor, u8 code, u8 *val, int len)
struct spi_mem_op op = SPI_MEM_OP(SPI_MEM_OP_CMD(code, 1),
SPI_MEM_OP_NO_ADDR,
SPI_MEM_OP_NO_DUMMY,
SPI_MEM_OP_DATA_IN(len, val, 1));
SPI_MEM_OP_DATA_IN(len, NULL, 1));
void *scratchbuf;
int ret;
scratchbuf = kmalloc(len, GFP_KERNEL);
if (!scratchbuf)
return -ENOMEM;
op.data.buf.in = scratchbuf;
ret = spi_mem_exec_op(flash->spimem, &op);
if (ret < 0)
dev_err(&flash->spimem->spi->dev, "error %d reading %x\n", ret,
code);
else
memcpy(val, scratchbuf, len);
kfree(scratchbuf);
return ret;
}
@ -56,9 +66,19 @@ static int m25p80_write_reg(struct spi_nor *nor, u8 opcode, u8 *buf, int len)
struct spi_mem_op op = SPI_MEM_OP(SPI_MEM_OP_CMD(opcode, 1),
SPI_MEM_OP_NO_ADDR,
SPI_MEM_OP_NO_DUMMY,
SPI_MEM_OP_DATA_OUT(len, buf, 1));
SPI_MEM_OP_DATA_OUT(len, NULL, 1));
void *scratchbuf;
int ret;
return spi_mem_exec_op(flash->spimem, &op);
scratchbuf = kmemdup(buf, len, GFP_KERNEL);
if (!scratchbuf)
return -ENOMEM;
op.data.buf.out = scratchbuf;
ret = spi_mem_exec_op(flash->spimem, &op);
kfree(scratchbuf);
return ret;
}
static ssize_t m25p80_write(struct spi_nor *nor, loff_t to, size_t len,