> On 03.08.22 08:57, Sherry Sun wrote:
> > Since commit 824a0a02cd74 ("dmaengine: imx-sdma: Add multi fifo
> > support") adds the use of
> > dma_slave_config->peripheral_config/peripheral_size to sdma driver,
> > the client drivers like uart need to initialize the
> > peripheral_config/peripheral_size for sdma, otherwise, the random
> > value of local variable slave_config may cause unexpected
> peripheral_config and make sdma mess up.
> >
>
> If this a fix, please add a Fixes: tag. I am not sure it is though, see below.
Hi Ahmad, thanks for the comments.
I don't think this patch is a fix for a specific commit, so we don't need the Fixes tag.
>
> > Signed-off-by: Sherry Sun <sherry.sun@xxxxxxx>
> > ---
> > drivers/tty/serial/imx.c | 4 ++++
> > 1 file changed, 4 insertions(+)
> >
> > diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c index
> > 522445a8f666..bb8c2a712e94 100644
> > --- a/drivers/tty/serial/imx.c
> > +++ b/drivers/tty/serial/imx.c
> > @@ -1320,6 +1320,8 @@ static int imx_uart_dma_init(struct imx_port
> > *sport)
>
> This function starts with
>
> struct dma_slave_config slave_config = {};
>
> > slave_config.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
> > /* one byte less than the watermark level to enable the aging timer
> */
> > slave_config.src_maxburst = RXTL_DMA - 1;
> > + slave_config.peripheral_config = NULL;
> > + slave_config.peripheral_size = 0;
>
> So these are already zero-initialized.
I am not sure actually, I think initialize a struct with {} cannot guarantee that all members are initialized to 0, it may depend on the compiler.
Best regards
Sherry
>
> > ret = dmaengine_slave_config(sport->dma_chan_rx, &slave_config);
> > if (ret) {
> > dev_err(dev, "error in RX dma configuration.\n"); @@ -
> 1346,6
> > +1348,8 @@ static int imx_uart_dma_init(struct imx_port *sport)
> > slave_config.dst_addr = sport->port.mapbase + URTX0;
> > slave_config.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
> > slave_config.dst_maxburst = TXTL_DMA;
> > + slave_config.peripheral_config = NULL;
> > + slave_config.peripheral_size = 0;
>
> Not sure if this is required. If preceding dmaengine_slave_config() indeed
> makes clearing necessary, you should note that in the commit message.
>
