i2c: rcar: skip DMA if buffer is not safe

This HW is prone to races, so it needs to setup new messages in irq
context. That means we can't alloc bounce buffers if a message buffer is
not DMA safe. So, in that case, simply fall back to PIO.

Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

diff --git a/drivers/i2c/busses/i2c-rcar.c b/drivers/i2c/busses/i2c-rcar.c
index 15d764afec3b29db443e5c225153270181fb2137..8a2ae3e6c561c41a2f7752debbdec145468d8024 100644 (file)
--- a/drivers/i2c/busses/i2c-rcar.c
+++ b/drivers/i2c/busses/i2c-rcar.c
@@ -359,7 +359,7 @@ static void rcar_i2c_dma(struct rcar_i2c_priv *priv)
        int len;
 
        /* Do not use DMA if it's not available or for messages < 8 bytes */
-       if (IS_ERR(chan) || msg->len < 8)
+       if (IS_ERR(chan) || msg->len < 8 || !(msg->flags & I2C_M_DMA_SAFE))
                return;
 
        if (read) {