Re: [RFC PATCH] brcmfmac: add 43751 SDIO ids and initialization

[Marc Gonzalez <marc.w.gonzalez@free.fr>]

On 09/03/2023 11:16, Marc Gonzalez wrote:

> On 06/03/2023 11:24, Marc Gonzalez wrote:
> 
>> # cat /sys/bus/sdio/devices/mmc2:0001:1/uevent
>> OF_NAME=wifi
>> OF_FULLNAME=/soc/sd@ffe03000/wifi@1
>> OF_COMPATIBLE_0=brcm,bcm4329-fmac
>> OF_COMPATIBLE_N=1
>> SDIO_CLASS=00
>> SDIO_ID=02D0:AAE7
>> SDIO_REVISION=0.0
>> MODALIAS=sdio:c00v02D0dAAE7
>>
>> NB: 0xaae7 = 43751
> 
> I have run into another issue.
> 
> The WiFi device (and the mmc2 bus it sits on) don't show up at all
> in the kernel log *unless* I add lots of debug output, such as with
> #define DEBUG in drivers/base/dd.c
> 
> I think this points to some kind of race condition?
> 
> Neil suggested that maybe the host probes the mmc2 bus "too soon",
> when the WiFi device is still powering up, which makes the entire
> probe fail.
> 
> This patch appears to solve the symptom:
> 
> diff --git a/drivers/mmc/host/meson-gx-mmc.c b/drivers/mmc/host/meson-gx-mmc.c
> index 6e5ea0213b477..999b3843c0d0b 100644
> --- a/drivers/mmc/host/meson-gx-mmc.c
> +++ b/drivers/mmc/host/meson-gx-mmc.c
> @@ -1400,7 +1400,7 @@ static struct platform_driver meson_mmc_driver = {
>  	.remove		= meson_mmc_remove,
>  	.driver		= {
>  		.name = DRIVER_NAME,
> -		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
> +		.probe_type = PROBE_FORCE_SYNCHRONOUS,
>  		.of_match_table = meson_mmc_of_match,
>  	},
>  };
> 
> But this might just be delaying the probe enough for the device
> to become ready?

FWIW, the relevant device tree nodes are:

/* decompiled DTS */

		sd@ffe03000 {
			compatible = "amlogic,meson-axg-mmc";
			reg = <0x0 0xffe03000 0x0 0x800>;
			interrupts = <0x0 0xbd 0x4>;
			status = "okay";
			clocks = <0x2 0x21 0x2 0x3c 0x2 0x2>;
			clock-names = "core", "clkin0", "clkin1";
			resets = <0x5 0x2c>;
			amlogic,dram-access-quirk;
			pinctrl-0 = <0x2c>;
			pinctrl-1 = <0x2d>;
			pinctrl-names = "default", "clk-gate";
			#address-cells = <0x1>;
			#size-cells = <0x0>;
			bus-width = <0x4>;
			cap-sd-highspeed;
			sd-uhs-sdr50;
			max-frequency = <0x5f5e100>;
			non-removable;
			disable-wp;
			keep-power-in-suspend;
			mmc-pwrseq = <0x2e>;
			vmmc-supply = <0x2b>;
			vqmmc-supply = <0x21>;

			wifi@1 {
				reg = <0x1>;
				compatible = "brcm,bcm4329-fmac";
			};
		};


/* original DTS */

		sd_emmc_a: sd@ffe03000 {
			compatible = "amlogic,meson-axg-mmc";
			reg = <0x0 0xffe03000 0x0 0x800>;
			interrupts = <GIC_SPI 189 IRQ_TYPE_LEVEL_HIGH>;
			status = "disabled";
			clocks = <&clkc CLKID_SD_EMMC_A>,
				 <&clkc CLKID_SD_EMMC_A_CLK0>,
				 <&clkc CLKID_FCLK_DIV2>;
			clock-names = "core", "clkin0", "clkin1";
			resets = <&reset RESET_SD_EMMC_A>;
		};

&sd_emmc_a {
	status = "okay";
	pinctrl-0 = <&sdio_pins>;
	pinctrl-1 = <&sdio_clk_gate_pins>;
	pinctrl-names = "default", "clk-gate";
	#address-cells = <1>;
	#size-cells = <0>;

	bus-width = <4>;
	cap-sd-highspeed;
	sd-uhs-sdr50;
	max-frequency = <100000000>;

	non-removable;
	disable-wp;

	/* WiFi firmware requires power to be kept while in suspend */
	keep-power-in-suspend;

	mmc-pwrseq = <&sdio_pwrseq>;

	vmmc-supply = <&vddao_3v3>;
	vqmmc-supply = <&vddio_ao1v8>;

	brcmf: wifi@1 {
		reg = <1>;
		compatible = "brcm,bcm4329-fmac";
	};
};

With an asynchronous probe, meson_mmc_probe() always succeeds,
yet the WiFi card is not detected later on, even if I sleep
1-2 seconds in meson_mmc_probe().

[    0.879756] YO: meson_mmc_probe: ffe03000.sd
[    0.914320] YO: meson_mmc_probe: ffe03000.sd ALL OK
[    1.199170] YO: meson_mmc_probe: ffe07000.mmc
[    1.232734] YO: meson_mmc_probe: ffe07000.mmc ALL OK

Confused again...

Regards


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