i2c_get_dma_safe_msg_buf() allocates space based on msg->len. If threshold is 0 and msg->len is also 0, function makes zero-length allocation, which returns a special ZERO_SIZE_PTR instead of a NULL pointer, and this will cause later code to fail. Modify the threshold to > 0 so the function returns NULL pointer. Fixes: fc66b39fe36a ("i2c: mediatek: Use DMA safe buffers for i2c transactions") Signed-off-by: Hsin-Yi Wang <hsinyi@xxxxxxxxxxxx> --- drivers/i2c/busses/i2c-mt65xx.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/drivers/i2c/busses/i2c-mt65xx.c b/drivers/i2c/busses/i2c-mt65xx.c index a74ef76705e0..2bb4d20ead32 100644 --- a/drivers/i2c/busses/i2c-mt65xx.c +++ b/drivers/i2c/busses/i2c-mt65xx.c @@ -503,7 +503,7 @@ static int mtk_i2c_do_transfer(struct mtk_i2c *i2c, struct i2c_msg *msgs, writel(I2C_DMA_INT_FLAG_NONE, i2c->pdmabase + OFFSET_INT_FLAG); writel(I2C_DMA_CON_RX, i2c->pdmabase + OFFSET_CON); - dma_rd_buf = i2c_get_dma_safe_msg_buf(msgs, 0); + dma_rd_buf = i2c_get_dma_safe_msg_buf(msgs, 1); if (!dma_rd_buf) return -ENOMEM; @@ -526,7 +526,7 @@ static int mtk_i2c_do_transfer(struct mtk_i2c *i2c, struct i2c_msg *msgs, writel(I2C_DMA_INT_FLAG_NONE, i2c->pdmabase + OFFSET_INT_FLAG); writel(I2C_DMA_CON_TX, i2c->pdmabase + OFFSET_CON); - dma_wr_buf = i2c_get_dma_safe_msg_buf(msgs, 0); + dma_wr_buf = i2c_get_dma_safe_msg_buf(msgs, 1); if (!dma_wr_buf) return -ENOMEM; @@ -549,7 +549,7 @@ static int mtk_i2c_do_transfer(struct mtk_i2c *i2c, struct i2c_msg *msgs, writel(I2C_DMA_CLR_FLAG, i2c->pdmabase + OFFSET_INT_FLAG); writel(I2C_DMA_CLR_FLAG, i2c->pdmabase + OFFSET_CON); - dma_wr_buf = i2c_get_dma_safe_msg_buf(msgs, 0); + dma_wr_buf = i2c_get_dma_safe_msg_buf(msgs, 1); if (!dma_wr_buf) return -ENOMEM; @@ -561,7 +561,7 @@ static int mtk_i2c_do_transfer(struct mtk_i2c *i2c, struct i2c_msg *msgs, return -ENOMEM; } - dma_rd_buf = i2c_get_dma_safe_msg_buf((msgs + 1), 0); + dma_rd_buf = i2c_get_dma_safe_msg_buf((msgs + 1), 1); if (!dma_rd_buf) { dma_unmap_single(i2c->dev, wpaddr, msgs->len, DMA_TO_DEVICE); -- 2.18.1