The patch below does not apply to the 4.9-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.

thanks,

greg k-h

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

From 9f9e3e0d4dd3338b3f3dde080789f71901e1e4ff Mon Sep 17 00:00:00 2001

From: Esben Haabendal eha@deif.com Date: Mon, 9 Jul 2018 11:43:01 +0200 Subject: [PATCH] i2c: imx: Fix reinit_completion() use MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit

Make sure to call reinit_completion() before dma is started to avoid race condition where reinit_completion() is called after complete() and before wait_for_completion_timeout().

Signed-off-by: Esben Haabendal eha@deif.com Fixes: ce1a78840ff7 ("i2c: imx: add DMA support for freescale i2c driver") Reviewed-by: Uwe Kleine-König u.kleine-koenig@pengutronix.de Signed-off-by: Wolfram Sang wsa@the-dreams.de Cc: stable@kernel.org

diff --git a/drivers/i2c/busses/i2c-imx.c b/drivers/i2c/busses/i2c-imx.c index 0207e194f84b..39cfd98c7b23 100644 --- a/drivers/i2c/busses/i2c-imx.c +++ b/drivers/i2c/busses/i2c-imx.c @@ -368,6 +368,7 @@ static int i2c_imx_dma_xfer(struct imx_i2c_struct *i2c_imx, goto err_desc; }

+ reinit_completion(&dma->cmd_complete); txdesc->callback = i2c_imx_dma_callback; txdesc->callback_param = i2c_imx; if (dma_submit_error(dmaengine_submit(txdesc))) { @@ -622,7 +623,6 @@ static int i2c_imx_dma_write(struct imx_i2c_struct *i2c_imx, * The first byte must be transmitted by the CPU. */ imx_i2c_write_reg(i2c_8bit_addr_from_msg(msgs), i2c_imx, IMX_I2C_I2DR); - reinit_completion(&i2c_imx->dma->cmd_complete); time_left = wait_for_completion_timeout( &i2c_imx->dma->cmd_complete, msecs_to_jiffies(DMA_TIMEOUT)); @@ -681,7 +681,6 @@ static int i2c_imx_dma_read(struct imx_i2c_struct *i2c_imx, if (result) return result;

- reinit_completion(&i2c_imx->dma->cmd_complete); time_left = wait_for_completion_timeout( &i2c_imx->dma->cmd_complete, msecs_to_jiffies(DMA_TIMEOUT));