On 09/17/2018 05:31 PM, Boris Brezillon wrote:
As documented in spi-mem.h, spi_mem_op->data.buf.{in,out} must be
DMA-able, and commit 4120f8d158ef ("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: 4120f8d158ef ("mtd: spi-nor: Use the spi_mem_xx() API")
Reported-by: Jarkko Nikula <jarkko.nikula@xxxxxxxxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Boris Brezillon <boris.brezillon@xxxxxxxxxxx>
---
Note that the ->{read,write}() path is still buggy since nothing
guarantees that buffers passed by the MTD layer to the SPI NOR layer
are DMA-able, but this is a long-standing issue which we'll have to
address at the spi-nor level (this layer can choose the bounce buffer
size based on nor->page_size).
Changes in v2:
- Copy the data from scratchbuf in the ->read_reg() path
---
drivers/mtd/devices/m25p80.c | 26 +++++++++++++++++++++++---
1 file changed, 23 insertions(+), 3 deletions(-)
Tested-by: Jarkko Nikula <jarkko.nikula@xxxxxxxxxxxxxxx>
Reviewed-by: Jarkko Nikula <jarkko.nikula@xxxxxxxxxxxxxxx>
