i2c: ismt: initialize DMA buffer

commit bf416910 upstream.

This patch adds code to initialize the DMA buffer to compensate for
possible hardware data corruption.
Signed-off-by: James Ralston <james.d.ralston@intel.com>
[wsa: changed to use 'sizeof']
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Cc: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/i2c/busses/i2c-ismt.c

@@ -393,6 +393,9 @@ static int ismt_access(struct i2c_adapter *adap, u16 addr,
 
 	desc = &priv->hw[priv->head];
 
+	/* Initialize the DMA buffer */
+	memset(priv->dma_buffer, 0, sizeof(priv->dma_buffer));
+
 	/* Initialize the descriptor */
 	memset(desc, 0, sizeof(struct ismt_desc));
 	desc->tgtaddr_rw = ISMT_DESC_ADDR_RW(addr, read_write);