[PATCH] dmaengine: ti: k3-udma: Fix an error handling path in 'k3_udma_glue_cfg_rx_flow()'

From: Christophe JAILLET
Date: Sun Mar 15 2020 - 11:50:26 EST


All but one error handling paths in the 'k3_udma_glue_cfg_rx_flow()'
function 'goto err' and call 'k3_udma_glue_release_rx_flow()'.

This not correct because this function has a 'channel->flows_ready--;' at
the end, but 'flows_ready' has not been incremented here, when we branch to
the error handling path.

In order to keep a correct value in 'flows_ready', un-roll
'k3_udma_glue_release_rx_flow()', simplify it, add some labels and branch
at the correct places when an error is detected.

Doing so, we also NULLify 'flow->udma_rflow' in a path that was lacking it.

Fixes: d70241913413 ("dmaengine: ti: k3-udma: Add glue layer for non DMAengine user")
Signed-off-by: Christophe JAILLET <christophe.jaillet@xxxxxxxxxx>
---
Not sure that the last point of the description is correct. Maybe, the
'xudma_rflow_put / return -ENODEV;' should be kept in order not to
override 'flow->udma_rflow'.
---
drivers/dma/ti/k3-udma-glue.c | 30 ++++++++++++++++++++----------
1 file changed, 20 insertions(+), 10 deletions(-)

diff --git a/drivers/dma/ti/k3-udma-glue.c b/drivers/dma/ti/k3-udma-glue.c
index dbccdc7c0ed5..890573eb1625 100644
--- a/drivers/dma/ti/k3-udma-glue.c
+++ b/drivers/dma/ti/k3-udma-glue.c
@@ -578,12 +578,12 @@ static int k3_udma_glue_cfg_rx_flow(struct k3_udma_glue_rx_channel *rx_chn,
if (IS_ERR(flow->udma_rflow)) {
ret = PTR_ERR(flow->udma_rflow);
dev_err(dev, "UDMAX rflow get err %d\n", ret);
- goto err;
+ goto err_return;
}

if (flow->udma_rflow_id != xudma_rflow_get_id(flow->udma_rflow)) {
- xudma_rflow_put(rx_chn->common.udmax, flow->udma_rflow);
- return -ENODEV;
+ ret = -ENODEV;
+ goto err_rflow_put;
}

/* request and cfg rings */
@@ -592,7 +592,7 @@ static int k3_udma_glue_cfg_rx_flow(struct k3_udma_glue_rx_channel *rx_chn,
if (!flow->ringrx) {
ret = -ENODEV;
dev_err(dev, "Failed to get RX ring\n");
- goto err;
+ goto err_rflow_put;
}

flow->ringrxfdq = k3_ringacc_request_ring(rx_chn->common.ringacc,
@@ -600,19 +600,19 @@ static int k3_udma_glue_cfg_rx_flow(struct k3_udma_glue_rx_channel *rx_chn,
if (!flow->ringrxfdq) {
ret = -ENODEV;
dev_err(dev, "Failed to get RXFDQ ring\n");
- goto err;
+ goto err_ringrx_free;
}

ret = k3_ringacc_ring_cfg(flow->ringrx, &flow_cfg->rx_cfg);
if (ret) {
dev_err(dev, "Failed to cfg ringrx %d\n", ret);
- goto err;
+ goto err_ringrxfdq_free;
}

ret = k3_ringacc_ring_cfg(flow->ringrxfdq, &flow_cfg->rxfdq_cfg);
if (ret) {
dev_err(dev, "Failed to cfg ringrxfdq %d\n", ret);
- goto err;
+ goto err_ringrxfdq_free;
}

if (rx_chn->remote) {
@@ -662,7 +662,7 @@ static int k3_udma_glue_cfg_rx_flow(struct k3_udma_glue_rx_channel *rx_chn,
if (ret) {
dev_err(dev, "flow%d config failed: %d\n", flow->udma_rflow_id,
ret);
- goto err;
+ goto err_ringrxfdq_free;
}

rx_chn->flows_ready++;
@@ -670,8 +670,18 @@ static int k3_udma_glue_cfg_rx_flow(struct k3_udma_glue_rx_channel *rx_chn,
flow->udma_rflow_id, rx_chn->flows_ready);

return 0;
-err:
- k3_udma_glue_release_rx_flow(rx_chn, flow_idx);
+
+err_ringrxfdq_free:
+ k3_ringacc_ring_free(flow->ringrxfdq);
+
+err_ringrx_free:
+ k3_ringacc_ring_free(flow->ringrx);
+
+err_rflow_put:
+ xudma_rflow_put(rx_chn->common.udmax, flow->udma_rflow);
+ flow->udma_rflow = NULL;
+
+err_return:
return ret;
}

--
2.20.1