The patch below does not apply to the 5.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.4.y git checkout FETCH_HEAD git cherry-pick -x 6aae87fe7f180cd93a74466cdb6cf2aa9bb28798 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to 'stable@vger.kernel.org' --in-reply-to '2025072107-provolone-sagging-274b@gregkh' --subject-prefix 'PATCH 5.4.y' HEAD^..

Possible dependencies:

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 6aae87fe7f180cd93a74466cdb6cf2aa9bb28798 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Cl=C3=A9ment=20Le=20Goffic?= clement.legoffic@foss.st.com Date: Fri, 4 Jul 2025 10:39:15 +0200 Subject: [PATCH] i2c: stm32f7: unmap DMA mapped buffer MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit

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: 7ecc8cfde553 ("i2c: i2c-stm32f7: Add DMA support") Signed-off-by: Clément Le Goffic clement.legoffic@foss.st.com Cc: stable@vger.kernel.org # v4.18+ Acked-by: Alain Volmat alain.volmat@foss.st.com Signed-off-by: Andi Shyti andi.shyti@kernel.org Link: https://lore.kernel.org/r/20250704-i2c-upstream-v4-2-84a095a2c728@foss.st.co...

diff --git a/drivers/i2c/busses/i2c-stm32f7.c b/drivers/i2c/busses/i2c-stm32f7.c index 817d081460c2..73a7b8894c0d 100644 --- a/drivers/i2c/busses/i2c-stm32f7.c +++ b/drivers/i2c/busses/i2c-stm32f7.c @@ -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; } }