On Sun, Feb 5, 2017 at 12:56 PM, Fabio Estevam <fabio.estevam@xxxxxxx> wrote: > [Sorry, for the top-posting] > > > imx6sx uart should be of a IMX6Q_UART instead. > > > Does this patch fix the issue? It seems this dts change will not fix the problem. > From: Kai Ruhnau <kai.ruhnau@xxxxxxxxxxxxx> > > In 1c06bde6 with the introduction of DMA support for the i.MX53 platform, > DMA was enabled for all platforms instead. On an i.MX6SX (which is a > IMX21_UART), this breaks gpsd talking to an UART module with > > imx-uart 21f4000.serial: DMA transaction error. > > This patch makes sure, UART DMA is only activated for i.MX53 and i.MX6Q. > > Signed-off-by: Kai Ruhnau <kai.ruhnau@xxxxxxxxxxxxx> > Reviewed-by: Marek Vasut <marex@xxxxxxx> > Fixes: 1c06bde643d0 ("Allowing UART DMA to be configured on i.MX53") > Cc: <stable@xxxxxxxxxxxxxxx> # 4.9+ > Cc: Fabio Estevam <fabio.estevam@xxxxxxx> > Cc: Martyn Welch <martyn.welch@xxxxxxxxxxxxxxx> > Cc: Shawn Guo <shawnguo@xxxxxxxxxx> > --- > drivers/tty/serial/imx.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c > index a70356d..8e2b5f2 100644 > --- a/drivers/tty/serial/imx.c > +++ b/drivers/tty/serial/imx.c > @@ -1269,7 +1269,8 @@ static int imx_startup(struct uart_port *port) > writel(temp & ~UCR4_DREN, sport->port.membase + UCR4); > > /* Can we enable the DMA support? */ > - if (!uart_console(port) && !sport->dma_is_inited) > + if ((is_imx6q_uart(sport) || is_imx53_uart(sport)) && > + !uart_console(port) && !sport->dma_is_inited) > imx_uart_dma_init(sport); Looks like imx serial DMA is broken in 4.9. There is also this report from Clemens: https://lkml.org/lkml/2017/1/4/579 Could anyone run a git bisect? -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html