On Fri, Mar 29, 2019 at 1:49 AM Andrey Smirnov <andrew.smir...@gmail.com> wrote:
>
> Since 25aaa75df1e6 SDMA driver uses clock rates of "ipg" and "ahb"
> clock to determine if it needs to configure the IP block as operating
> at 1:1 or 1:2 clock ratio (ACR bit in SDMAARM_CONFIG). Specifying both
> clocks as IMX6QDL_CLK_SDMA results in driver incorrectly thinking that
> ratio is 1:1 which results in broken SDMA funtionality(this at least
> breaks RAVE SP serdev driver on RDU2). Fix the code to specify
> IMX6QDL_CLK_IPG as "ipg" clock for SDMA, to avoid detecting incorrect
> clock ratio.
>
Thank you for this!  I the 5.1 kernel is the first revision to include
the i.MX6 kit from Logic PD and I thought I messed something up, so I
was off in a completely different direction trying to figure out why
it was broken.  With your patch, my board works again!

> Fixes: 25aaa75df1e6 ("dmaengine: imx-sdma: add clock ratio 1:1 check")
> Signed-off-by: Andrey Smirnov <andrew.smir...@gmail.com>
> Reviewed-by: Lucas Stach <l.st...@pengutronix.de>

Tested-by: Adam Ford <aford...@gmail.com> #imx6q-logicpd

> Cc: Angus Ainslie (Purism) <an...@akkea.ca>
> Cc: Chris Healy <cphe...@gmail.com>
> Cc: Lucas Stach <l.st...@pengutronix.de>
> Cc: Fabio Estevam <fabio.este...@nxp.com>
> Cc: Shawn Guo <shawn...@kernel.org>
> Cc: linux-arm-ker...@lists.infradead.org
> Cc: linux-kernel@vger.kernel.org
> ---
>  arch/arm/boot/dts/imx6qdl.dtsi | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/arm/boot/dts/imx6qdl.dtsi b/arch/arm/boot/dts/imx6qdl.dtsi
> index 9f9aa6e7ed0e..354feba077b2 100644
> --- a/arch/arm/boot/dts/imx6qdl.dtsi
> +++ b/arch/arm/boot/dts/imx6qdl.dtsi
> @@ -949,7 +949,7 @@
>                                 compatible = "fsl,imx6q-sdma", 
> "fsl,imx35-sdma";
>                                 reg = <0x020ec000 0x4000>;
>                                 interrupts = <0 2 IRQ_TYPE_LEVEL_HIGH>;
> -                               clocks = <&clks IMX6QDL_CLK_SDMA>,
> +                               clocks = <&clks IMX6QDL_CLK_IPG>,
>                                          <&clks IMX6QDL_CLK_SDMA>;
>                                 clock-names = "ipg", "ahb";
>                                 #dma-cells = <3>;
> --
> 2.20.1
>
>
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