FAILED: patch "[PATCH] i2c: imx: Fix reinit_completion() use" failed to apply to 4.9-stable tree

FAILED: patch "[PATCH] i2c: imx: Fix reinit_completion() use" failed to apply to 4.9-stable tree

[gregkh]

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));