This is a note to let you know that I've just added the patch titled i2c: tegra: Allocate DMA memory for DMA engine to the 6.0-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: i2c-tegra-allocate-dma-memory-for-dma-engine.patch and it can be found in the queue-6.0 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit c9a1da981badf102e0652d89f11ac1ae0a9cfc01 Author: Thierry Reding <treding@xxxxxxxxxx> Date: Thu Oct 20 16:39:33 2022 +0200 i2c: tegra: Allocate DMA memory for DMA engine [ Upstream commit cdbf26251d3b35c4ccaea0c3a6de4318f727d3d2 ] When the I2C controllers are running in DMA mode, it is the DMA engine that performs the memory accesses rather than the I2C controller. Pass the DMA engine's struct device pointer to the DMA API to make sure the correct DMA operations are used. This fixes an issue where the DMA engine's SMMU stream ID needs to be misleadingly set for the I2C controllers in device tree. Suggested-by: Robin Murphy <robin.murphy@xxxxxxx> Signed-off-by: Thierry Reding <treding@xxxxxxxxxx> Signed-off-by: Wolfram Sang <wsa@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/i2c/busses/i2c-tegra.c b/drivers/i2c/busses/i2c-tegra.c index 031c78ac42e6..a24cc413c89b 100644 --- a/drivers/i2c/busses/i2c-tegra.c +++ b/drivers/i2c/busses/i2c-tegra.c @@ -284,6 +284,7 @@ struct tegra_i2c_dev { struct dma_chan *tx_dma_chan; struct dma_chan *rx_dma_chan; unsigned int dma_buf_size; + struct device *dma_dev; dma_addr_t dma_phys; void *dma_buf; @@ -420,7 +421,7 @@ static int tegra_i2c_dma_submit(struct tegra_i2c_dev *i2c_dev, size_t len) static void tegra_i2c_release_dma(struct tegra_i2c_dev *i2c_dev) { if (i2c_dev->dma_buf) { - dma_free_coherent(i2c_dev->dev, i2c_dev->dma_buf_size, + dma_free_coherent(i2c_dev->dma_dev, i2c_dev->dma_buf_size, i2c_dev->dma_buf, i2c_dev->dma_phys); i2c_dev->dma_buf = NULL; } @@ -467,10 +468,13 @@ static int tegra_i2c_init_dma(struct tegra_i2c_dev *i2c_dev) i2c_dev->tx_dma_chan = chan; + WARN_ON(i2c_dev->tx_dma_chan->device != i2c_dev->rx_dma_chan->device); + i2c_dev->dma_dev = chan->device->dev; + i2c_dev->dma_buf_size = i2c_dev->hw->quirks->max_write_len + I2C_PACKET_HEADER_SIZE; - dma_buf = dma_alloc_coherent(i2c_dev->dev, i2c_dev->dma_buf_size, + dma_buf = dma_alloc_coherent(i2c_dev->dma_dev, i2c_dev->dma_buf_size, &dma_phys, GFP_KERNEL | __GFP_NOWARN); if (!dma_buf) { dev_err(i2c_dev->dev, "failed to allocate DMA buffer\n"); @@ -1267,7 +1271,7 @@ static int tegra_i2c_xfer_msg(struct tegra_i2c_dev *i2c_dev, if (i2c_dev->dma_mode) { if (i2c_dev->msg_read) { - dma_sync_single_for_device(i2c_dev->dev, + dma_sync_single_for_device(i2c_dev->dma_dev, i2c_dev->dma_phys, xfer_size, DMA_FROM_DEVICE); @@ -1275,7 +1279,7 @@ static int tegra_i2c_xfer_msg(struct tegra_i2c_dev *i2c_dev, if (err) return err; } else { - dma_sync_single_for_cpu(i2c_dev->dev, + dma_sync_single_for_cpu(i2c_dev->dma_dev, i2c_dev->dma_phys, xfer_size, DMA_TO_DEVICE); } @@ -1288,7 +1292,7 @@ static int tegra_i2c_xfer_msg(struct tegra_i2c_dev *i2c_dev, memcpy(i2c_dev->dma_buf + I2C_PACKET_HEADER_SIZE, msg->buf, msg->len); - dma_sync_single_for_device(i2c_dev->dev, + dma_sync_single_for_device(i2c_dev->dma_dev, i2c_dev->dma_phys, xfer_size, DMA_TO_DEVICE); @@ -1339,7 +1343,7 @@ static int tegra_i2c_xfer_msg(struct tegra_i2c_dev *i2c_dev, } if (i2c_dev->msg_read && i2c_dev->msg_err == I2C_ERR_NONE) { - dma_sync_single_for_cpu(i2c_dev->dev, + dma_sync_single_for_cpu(i2c_dev->dma_dev, i2c_dev->dma_phys, xfer_size, DMA_FROM_DEVICE);