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[1/2] i2c: rcar: update to new DMAENGINE API when terminating

Message ID 20211208084543.20181-1-wsa+renesas@sang-engineering.com
State Accepted
Commit a5f7cf953f2b47e5025a7acd1698eea997b2fd94
Headers show
Series [1/2] i2c: rcar: update to new DMAENGINE API when terminating | expand

Commit Message

Wolfram Sang Dec. 8, 2021, 8:45 a.m. UTC 
dmaengine_terminate_all() is deprecated. When converting the existing
calls, it turned out that the termination in the interrupt handlers was
superfluous and only a side effect of simply calling
rcar_i2c_cleanup_dma(). As either no DMA transfers have been submitted
yet or the last one has successfully completed, there is nothing to
terminate and we can leave it out. So, merge the DMA unmap and cleanup
function to save some code. Then, add a flag if the new cleanup function
needs to terminate DMA. This is only the case for the erorr handling in
the main thread, so we can finally switch from dmaengine_terminate_all()
to dmaengine_terminate_sync() here.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
---
 drivers/i2c/busses/i2c-rcar.c | 26 +++++++++-----------------
 1 file changed, 9 insertions(+), 17 deletions(-)

Comments

Wolfram Sang Dec. 16, 2021, 9:23 p.m. UTC | #1 
On Wed, Dec 08, 2021 at 09:45:42AM +0100, Wolfram Sang wrote:
> dmaengine_terminate_all() is deprecated. When converting the existing
> calls, it turned out that the termination in the interrupt handlers was
> superfluous and only a side effect of simply calling
> rcar_i2c_cleanup_dma(). As either no DMA transfers have been submitted
> yet or the last one has successfully completed, there is nothing to
> terminate and we can leave it out. So, merge the DMA unmap and cleanup
> function to save some code. Then, add a flag if the new cleanup function
> needs to terminate DMA. This is only the case for the erorr handling in
> the main thread, so we can finally switch from dmaengine_terminate_all()
> to dmaengine_terminate_sync() here.
> 
> Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>

Applied to for-next, thanks!
diff mbox series

Patch

diff --git a/drivers/i2c/busses/i2c-rcar.c b/drivers/i2c/busses/i2c-rcar.c
index fc13511f4562..f71c730f9838 100644
--- a/drivers/i2c/busses/i2c-rcar.c
+++ b/drivers/i2c/busses/i2c-rcar.c
@@ -367,11 +367,15 @@  static void rcar_i2c_next_msg(struct rcar_i2c_priv *priv)
 	rcar_i2c_prepare_msg(priv);
 }
 
-static void rcar_i2c_dma_unmap(struct rcar_i2c_priv *priv)
+static void rcar_i2c_cleanup_dma(struct rcar_i2c_priv *priv, bool terminate)
 {
 	struct dma_chan *chan = priv->dma_direction == DMA_FROM_DEVICE
 		? priv->dma_rx : priv->dma_tx;
 
+	/* only allowed from thread context! */
+	if (terminate)
+		dmaengine_terminate_sync(chan);
+
 	dma_unmap_single(chan->device->dev, sg_dma_address(&priv->sg),
 			 sg_dma_len(&priv->sg), priv->dma_direction);
 
@@ -386,25 +390,13 @@  static void rcar_i2c_dma_unmap(struct rcar_i2c_priv *priv)
 	rcar_i2c_write(priv, ICDMAER, 0);
 }
 
-static void rcar_i2c_cleanup_dma(struct rcar_i2c_priv *priv)
-{
-	if (priv->dma_direction == DMA_NONE)
-		return;
-	else if (priv->dma_direction == DMA_FROM_DEVICE)
-		dmaengine_terminate_all(priv->dma_rx);
-	else if (priv->dma_direction == DMA_TO_DEVICE)
-		dmaengine_terminate_all(priv->dma_tx);
-
-	rcar_i2c_dma_unmap(priv);
-}
-
 static void rcar_i2c_dma_callback(void *data)
 {
 	struct rcar_i2c_priv *priv = data;
 
 	priv->pos += sg_dma_len(&priv->sg);
 
-	rcar_i2c_dma_unmap(priv);
+	rcar_i2c_cleanup_dma(priv, false);
 }
 
 static bool rcar_i2c_dma(struct rcar_i2c_priv *priv)
@@ -456,7 +448,7 @@  static bool rcar_i2c_dma(struct rcar_i2c_priv *priv)
 					 DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
 	if (!txdesc) {
 		dev_dbg(dev, "dma prep slave sg failed, using PIO\n");
-		rcar_i2c_cleanup_dma(priv);
+		rcar_i2c_cleanup_dma(priv, false);
 		return false;
 	}
 
@@ -466,7 +458,7 @@  static bool rcar_i2c_dma(struct rcar_i2c_priv *priv)
 	cookie = dmaengine_submit(txdesc);
 	if (dma_submit_error(cookie)) {
 		dev_dbg(dev, "submitting dma failed, using PIO\n");
-		rcar_i2c_cleanup_dma(priv);
+		rcar_i2c_cleanup_dma(priv, false);
 		return false;
 	}
 
@@ -846,7 +838,7 @@  static int rcar_i2c_master_xfer(struct i2c_adapter *adap,
 
 	/* cleanup DMA if it couldn't complete properly due to an error */
 	if (priv->dma_direction != DMA_NONE)
-		rcar_i2c_cleanup_dma(priv);
+		rcar_i2c_cleanup_dma(priv, true);
 
 	if (!time_left) {
 		rcar_i2c_init(priv);