Cc += Yuan Yao who authored DMA support and the NXP team. On Wed, May 23, 2018 at 11:56:20AM +0200, Esben Haabendal wrote: > From: Esben Haabendal <eha@xxxxxxxx> > > Make sure to call reinit_completion() before dma is started to avoid race > condition where reinit_compleition() is called after complete() and before s/compleition/completion/ > wait_for_completion_timeout(). Is this a theoretical problem, or did it trigger on your side? > Signed-off-by: Esben Haabendal <eha@xxxxxxxx> Fixes: ce1a78840ff7 ("i2c: imx: add DMA support for freescale i2c driver") Reviewed-by: Uwe Kleine-König <u.kleine-koenig@xxxxxxxxxxxxxx> > --- > drivers/i2c/busses/i2c-imx.c | 3 +-- > 1 file changed, 1 insertion(+), 2 deletions(-) > > diff --git a/drivers/i2c/busses/i2c-imx.c b/drivers/i2c/busses/i2c-imx.c > index d7267dd9c7bf..6fca5e64cffb 100644 > --- a/drivers/i2c/busses/i2c-imx.c > +++ b/drivers/i2c/busses/i2c-imx.c > @@ -377,6 +377,7 @@ 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))) { > @@ -631,7 +632,6 @@ 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(msgs->addr << 1, 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)); > @@ -690,7 +690,6 @@ 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)); Best regards Uwe -- Pengutronix e.K. | Uwe Kleine-König | Industrial Linux Solutions | http://www.pengutronix.de/ |