[PATCH] i2c: qcom-geni: Fix GPI DMA buffer sync-back

[Robin Reckmann]

Fix i2c transfers using GPI DMA mode for all message types that do not set
the I2C_M_DMA_SAFE flag (e.g. SMBus "read byte").

In this case a bounce buffer is returned by i2c_get_dma_safe_msg_buf(),
and it has to synced back to the message after the transfer is done.

Add missing assignment of dma buffer in geni_i2c_gpi().

Set xferred in i2c_put_dma_safe_msg_buf() to true in case of no error to
ensure the sync-back of this dma buffer to the message.

Signed-off-by: Robin Reckmann <robin.reckmann at gmail.com>
---
 drivers/i2c/busses/i2c-qcom-geni.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/i2c/busses/i2c-qcom-geni.c b/drivers/i2c/busses/i2c-qcom-geni.c
index 6ac402ea58fb..d3541e94794e 100644
--- a/drivers/i2c/busses/i2c-qcom-geni.c
+++ b/drivers/i2c/busses/i2c-qcom-geni.c
@@ -484,12 +484,12 @@ static void geni_i2c_gpi_unmap(struct geni_i2c_dev *gi2c, struct i2c_msg *msg,
 {
 	if (tx_buf) {
 		dma_unmap_single(gi2c->se.dev->parent, tx_addr, msg->len, DMA_TO_DEVICE);
-		i2c_put_dma_safe_msg_buf(tx_buf, msg, false);
+		i2c_put_dma_safe_msg_buf(tx_buf, msg, !gi2c->err);
 	}
 
 	if (rx_buf) {
 		dma_unmap_single(gi2c->se.dev->parent, rx_addr, msg->len, DMA_FROM_DEVICE);
-		i2c_put_dma_safe_msg_buf(rx_buf, msg, false);
+		i2c_put_dma_safe_msg_buf(rx_buf, msg, !gi2c->err);
 	}
 }
 
@@ -553,6 +553,7 @@ static int geni_i2c_gpi(struct geni_i2c_dev *gi2c, struct i2c_msg *msg,
 	desc->callback_param = gi2c;
 
 	dmaengine_submit(desc);
+	*buf = dma_buf;
 	*dma_addr_p = addr;
 
 	return 0;
-- 
2.25.1