Commit 6aae87fe authored by Clément Le Goffic's avatar Clément Le Goffic Committed by Andi Shyti
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i2c: stm32f7: unmap DMA mapped buffer 



Before each I2C transfer using DMA, the I2C buffer is DMA'pped to make
sure the memory buffer is DMA'able. This is handle in the function
`stm32_i2c_prep_dma_xfer()`.
If the transfer fails for any reason the I2C buffer must be unmap.
Use the dma_callback to factorize the code and fix this issue.

Note that the `stm32f7_i2c_dma_callback()` is now called in case of DMA
transfer success and error and that the `complete()` on the dma_complete
completion structure is done inconditionnally in case of transfer
success or error as well as the `dmaengine_terminate_async()`.
This is allowed as a `complete()` in case transfer error has no effect
as well as a `dmaengine_terminate_async()` on a transfer success.

Also fix the unneeded cast and remove not more needed variables.

Fixes: 7ecc8cfd ("i2c: i2c-stm32f7: Add DMA support")
Signed-off-by: default avatarClément Le Goffic <clement.legoffic@foss.st.com>
Cc: <stable@vger.kernel.org> # v4.18+
Acked-by: default avatarAlain Volmat <alain.volmat@foss.st.com>
Signed-off-by: default avatarAndi Shyti <andi.shyti@kernel.org>
Link: https://lore.kernel.org/r/20250704-i2c-upstream-v4-2-84a095a2c728@foss.st.com
parent c870cbbd

drivers/i2c/busses/i2c-stm32f7.c

+7 −13
Original line number Diff line number Diff line
@@ -739,10 +739,11 @@ static void stm32f7_i2c_disable_dma_req(struct stm32f7_i2c_dev *i2c_dev) 


static void stm32f7_i2c_dma_callback(void *arg)

{

	struct stm32f7_i2c_dev *i2c_dev = (struct stm32f7_i2c_dev *)arg;

	struct stm32f7_i2c_dev *i2c_dev = arg;

	struct stm32_i2c_dma *dma = i2c_dev->dma;



	stm32f7_i2c_disable_dma_req(i2c_dev);

	dmaengine_terminate_async(dma->chan_using);

	dma_unmap_single(i2c_dev->dev, dma->dma_buf, dma->dma_len,

			 dma->dma_data_dir);

	complete(&dma->dma_complete);
@@ -1510,7 +1511,6 @@ static irqreturn_t stm32f7_i2c_handle_isr_errs(struct stm32f7_i2c_dev *i2c_dev, 
	u16 addr = f7_msg->addr;

	void __iomem *base = i2c_dev->base;

	struct device *dev = i2c_dev->dev;

	struct stm32_i2c_dma *dma = i2c_dev->dma;



	/* Bus error */

	if (status & STM32F7_I2C_ISR_BERR) {
@@ -1551,10 +1551,8 @@ static irqreturn_t stm32f7_i2c_handle_isr_errs(struct stm32f7_i2c_dev *i2c_dev, 
	}



	/* Disable dma */

	if (i2c_dev->use_dma) {

		stm32f7_i2c_disable_dma_req(i2c_dev);

		dmaengine_terminate_async(dma->chan_using);

	}

	if (i2c_dev->use_dma)

		stm32f7_i2c_dma_callback(i2c_dev);



	i2c_dev->master_mode = false;

	complete(&i2c_dev->complete);
@@ -1600,7 +1598,6 @@ static irqreturn_t stm32f7_i2c_isr_event_thread(int irq, void *data) 
{

	struct stm32f7_i2c_dev *i2c_dev = data;

	struct stm32f7_i2c_msg *f7_msg = &i2c_dev->f7_msg;

	struct stm32_i2c_dma *dma = i2c_dev->dma;

	void __iomem *base = i2c_dev->base;

	u32 status, mask;

	int ret;
@@ -1619,10 +1616,8 @@ static irqreturn_t stm32f7_i2c_isr_event_thread(int irq, void *data) 
		dev_dbg(i2c_dev->dev, "<%s>: Receive NACK (addr %x)\n",

			__func__, f7_msg->addr);

		writel_relaxed(STM32F7_I2C_ICR_NACKCF, base + STM32F7_I2C_ICR);

		if (i2c_dev->use_dma) {

			stm32f7_i2c_disable_dma_req(i2c_dev);

			dmaengine_terminate_async(dma->chan_using);

		}

		if (i2c_dev->use_dma)

			stm32f7_i2c_dma_callback(i2c_dev);

		f7_msg->result = -ENXIO;

	}
@@ -1640,8 +1635,7 @@ static irqreturn_t stm32f7_i2c_isr_event_thread(int irq, void *data) 
			ret = wait_for_completion_timeout(&i2c_dev->dma->dma_complete, HZ);

			if (!ret) {

				dev_dbg(i2c_dev->dev, "<%s>: Timed out\n", __func__);

				stm32f7_i2c_disable_dma_req(i2c_dev);

				dmaengine_terminate_async(dma->chan_using);

				stm32f7_i2c_dma_callback(i2c_dev);

				f7_msg->result = -ETIMEDOUT;

			}

		}