[PATCH v2] arm64: dts: amlogic: Fix SDIO interrupt and make it level-sensitive

[Neil Armstrong]

Hi Heiner,

On 25/01/2023 08:00, Heiner Kallweit wrote:
> SDIO specification defines that the interrupt is level-sensitive.
> Fix the interrupt trigger type for emmc_a accordingly.
> See comment at beginning of the file wrt which is the SDIO port.
> mmc2 = &sd_emmc_a; /* SDIO */
> 
> The usage of edge-triggered interrupts lead to lost interrupts under load,
> see [0]. This was confirmed to be fixed by using level-triggered
> interrupts.
> 
> Note:
> SDIO interrupt support was added in Linux just recently, however other
> users of this dts may be affected too.

Switching from edge to level has already fixed performance issues on ethernet,
so I think this would be the right direction, but since the SDIO, eMMC and SD controllers
are basically the same IP, they should have the same interrupt setup.

It makes no sense to have level only for SDIO, so perhaps it would be right to
switch every controllers to LEVEL (including AXG) and test to see if there's no regressions.

Neil

> 
> [0] https://www.spinics.net/lists/linux-mmc/msg73991.html
> 
> Fixes: 1499218c80c9 ("arm64: dts: move common G12A & G12B modes to meson-g12-common.dtsi")
> Reported-by: Peter Suti <peter.suti at streamunlimited.com>
> Tested-by: Peter Suti <peter.suti at streamunlimited.com>
> Cc: stable at vger.kernel.org
> Signed-off-by: Heiner Kallweit <hkallweit1 at gmail.com>
> ---
> v2:
> - rebase considering recent node name change sd -> mmc for sd_emmc_a
> ---
>   arch/arm64/boot/dts/amlogic/meson-g12-common.dtsi | 2 +-
>   arch/arm64/boot/dts/amlogic/meson-gx.dtsi         | 2 +-
>   2 files changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/arch/arm64/boot/dts/amlogic/meson-g12-common.dtsi b/arch/arm64/boot/dts/amlogic/meson-g12-common.dtsi
> index 1a931d5c2..c09eb9f6f 100644
> --- a/arch/arm64/boot/dts/amlogic/meson-g12-common.dtsi
> +++ b/arch/arm64/boot/dts/amlogic/meson-g12-common.dtsi
> @@ -2324,7 +2324,7 @@ uart_A: serial at 24000 {
>   		sd_emmc_a: mmc at ffe03000 {
>   			compatible = "amlogic,meson-axg-mmc";
>   			reg = <0x0 0xffe03000 0x0 0x800>;
> -			interrupts = <GIC_SPI 189 IRQ_TYPE_EDGE_RISING>;
> +			interrupts = <GIC_SPI 189 IRQ_TYPE_LEVEL_HIGH>;
>   			status = "disabled";
>   			clocks = <&clkc CLKID_SD_EMMC_A>,
>   				 <&clkc CLKID_SD_EMMC_A_CLK0>,
> diff --git a/arch/arm64/boot/dts/amlogic/meson-gx.dtsi b/arch/arm64/boot/dts/amlogic/meson-gx.dtsi
> index a79a35e84..ae1a5a568 100644
> --- a/arch/arm64/boot/dts/amlogic/meson-gx.dtsi
> +++ b/arch/arm64/boot/dts/amlogic/meson-gx.dtsi
> @@ -603,7 +603,7 @@ apb: apb at d0000000 {
>   			sd_emmc_a: mmc at 70000 {
>   				compatible = "amlogic,meson-gx-mmc", "amlogic,meson-gxbb-mmc";
>   				reg = <0x0 0x70000 0x0 0x800>;
> -				interrupts = <GIC_SPI 216 IRQ_TYPE_EDGE_RISING>;
> +				interrupts = <GIC_SPI 216 IRQ_TYPE_LEVEL_HIGH>;
>   				status = "disabled";
>   			};
>