[PATCH 5.19 156/365] i2c: qcom-geni: Fix GPI DMA buffer sync-back

From: Greg Kroah-Hartman
Date: Tue Aug 23 2022 - 04:52:20 EST


From: Robin Reckmann <robin.reckmann@xxxxxxxxxxxxxx>

commit 8689b80b22dbf1f5e993233370fe57f08731b14d upstream.

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.

Fixes: d8703554f4de ("i2c: qcom-geni: Add support for GPI DMA")
Signed-off-by: Robin Reckmann <robin.reckmann@xxxxxxxxx>
Tested-by: Luca Weiss <luca.weiss@xxxxxxxxxxxxx>
Tested-by: Caleb Connolly <caleb@xxxxxxxxxxxxx>
Reviewed-by: Konrad Dybcio <konrad.dybcio@xxxxxxxxxxxxxx>
Signed-off-by: Wolfram Sang <wsa@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/i2c/busses/i2c-qcom-geni.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)

--- 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 ge
{
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_
desc->callback_param = gi2c;

dmaengine_submit(desc);
+ *buf = dma_buf;
*dma_addr_p = addr;

return 0;