[PATCH V2] dmaengine: ti: k3-udma-glue: Fix an error handling path in 'k3_udma_glue_cfg_rx_flow()'

[PATCH V2] dmaengine: ti: k3-udma-glue: Fix an error handling path in 'k3_udma_glue_cfg_rx_flow()'

[Christophe JAILLET]

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@wanadoo.fr>
---
V2: adjust subject
    direct return in the first error handling path
---
 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;
+		return ret;
 	}
 
 	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 +670,17 @@ 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;
+
 	return ret;
 }
 
-- 
2.20.1

Re: [PATCH V2] dmaengine: ti: k3-udma-glue: Fix an error handling path in 'k3_udma_glue_cfg_rx_flow()'

[Peter Ujfalusi]

Hi Christophe,

On 18/03/2020 21.12, Christophe JAILLET wrote:
> 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@wanadoo.fr>
> ---
> V2: adjust subject
>     direct return in the first error handling path

Thank you!

Acked-by: Peter Ujfalusi <peter.ujfalusi@ti.com>

> ---
>  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;
> +		return ret;
>  	}
>  
>  	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 +670,17 @@ 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;
> +
>  	return ret;
>  }
>  
> 

- Péter

Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki.
Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki

Re: [PATCH V2] dmaengine: ti: k3-udma-glue: Fix an error handling path in 'k3_udma_glue_cfg_rx_flow()'

[Vinod Koul]

On 18-03-20, 20:12, Christophe JAILLET wrote:
> 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.

Applied, thanks

-- 
~Vinod