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

Message ID 20211208084543.20181-2-wsa+renesas@sang-engineering.com
State Accepted
Commit 44df8a79283d94f4aed2e3a14ed67e49a3c210ca
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 DMA setup and callback
were 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-sh_mobile.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 09:45:43AM +0100, Wolfram Sang wrote:
> dmaengine_terminate_all() is deprecated. When converting the existing
> calls, it turned out that the termination in the DMA setup and callback
> were 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!
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Patch

diff --git a/drivers/i2c/busses/i2c-sh_mobile.c b/drivers/i2c/busses/i2c-sh_mobile.c
index db8fa4186814..7b8caf172851 100644
--- a/drivers/i2c/busses/i2c-sh_mobile.c
+++ b/drivers/i2c/busses/i2c-sh_mobile.c
@@ -442,34 +442,26 @@  static irqreturn_t sh_mobile_i2c_isr(int irq, void *dev_id)
 	return IRQ_HANDLED;
 }
 
-static void sh_mobile_i2c_dma_unmap(struct sh_mobile_i2c_data *pd)
+static void sh_mobile_i2c_cleanup_dma(struct sh_mobile_i2c_data *pd, bool terminate)
 {
 	struct dma_chan *chan = pd->dma_direction == DMA_FROM_DEVICE
 				? pd->dma_rx : pd->dma_tx;
 
+	/* only allowed from thread context! */
+	if (terminate)
+		dmaengine_terminate_sync(chan);
+
 	dma_unmap_single(chan->device->dev, sg_dma_address(&pd->sg),
 			 pd->msg->len, pd->dma_direction);
 
 	pd->dma_direction = DMA_NONE;
 }
 
-static void sh_mobile_i2c_cleanup_dma(struct sh_mobile_i2c_data *pd)
-{
-	if (pd->dma_direction == DMA_NONE)
-		return;
-	else if (pd->dma_direction == DMA_FROM_DEVICE)
-		dmaengine_terminate_sync(pd->dma_rx);
-	else if (pd->dma_direction == DMA_TO_DEVICE)
-		dmaengine_terminate_sync(pd->dma_tx);
-
-	sh_mobile_i2c_dma_unmap(pd);
-}
-
 static void sh_mobile_i2c_dma_callback(void *data)
 {
 	struct sh_mobile_i2c_data *pd = data;
 
-	sh_mobile_i2c_dma_unmap(pd);
+	sh_mobile_i2c_cleanup_dma(pd, false);
 	pd->pos = pd->msg->len;
 	pd->stop_after_dma = true;
 
@@ -549,7 +541,7 @@  static void sh_mobile_i2c_xfer_dma(struct sh_mobile_i2c_data *pd)
 					 DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
 	if (!txdesc) {
 		dev_dbg(pd->dev, "dma prep slave sg failed, using PIO\n");
-		sh_mobile_i2c_cleanup_dma(pd);
+		sh_mobile_i2c_cleanup_dma(pd, false);
 		return;
 	}
 
@@ -559,7 +551,7 @@  static void sh_mobile_i2c_xfer_dma(struct sh_mobile_i2c_data *pd)
 	cookie = dmaengine_submit(txdesc);
 	if (dma_submit_error(cookie)) {
 		dev_dbg(pd->dev, "submitting dma failed, using PIO\n");
-		sh_mobile_i2c_cleanup_dma(pd);
+		sh_mobile_i2c_cleanup_dma(pd, false);
 		return;
 	}
 
@@ -698,7 +690,7 @@  static int sh_mobile_xfer(struct sh_mobile_i2c_data *pd,
 		if (!time_left) {
 			dev_err(pd->dev, "Transfer request timed out\n");
 			if (pd->dma_direction != DMA_NONE)
-				sh_mobile_i2c_cleanup_dma(pd);
+				sh_mobile_i2c_cleanup_dma(pd, true);
 
 			err = -ETIMEDOUT;
 			break;