[Letux-kernel] [PATCH] mmc: hack pwrseq to fix gta04 bt problems

[H. Nikolaus Schaller]

Hi,
can it be that simple?

Probably no.

Let's check with wl18xx driver where I have the omap5-pyra sample:

omap5-board-common.dtsi:

	mmc3_pwrseq: sdhci0_pwrseq {
		compatible = "mmc-pwrseq-simple";
		clocks = <&clk32kgaudio>;
		clock-names = "ext_clock";
	};

	vmmcsdio_fixed: fixedregulator-mmcsdio {
		compatible = "regulator-fixed";
		regulator-name = "vmmcsdio_fixed";
		regulator-min-microvolt = <1800000>;
		regulator-max-microvolt = <1800000>;
		gpio = <&gpio5 12 GPIO_ACTIVE_HIGH>;	/* gpio140 WLAN_EN */
		enable-active-high;
		startup-delay-us = <70000>;
		pinctrl-names = "default";
		pinctrl-0 = <&wlan_pins>;
	};

&mmc3 {
	vmmc-supply = <&vmmcsdio_fixed>;
	mmc-pwrseq = <&mmc3_pwrseq>;
	bus-width = <4>;
	non-removable;
	cap-power-off-card;
...
	wlcore: wlcore at 2 {
...
	};
};

So that is interesting. There is no reset handled by mmc-pwrseq-simple. Just clock
enabled.

This means the patch should not affect. Needs testing of course (well, I have
not yet tested *any* suspend on the OMAP5, it is too fresh).

But other devices? Basically we remove the reset during suspend.
Which should not harm since the vmmc-supply is usually also disabled.

BR,
Nikolaus


Am 08.02.2016 um 22:17 schrieb Andreas Kemnade <andreas at kemnade.info>:

> The reset pin is set to 1 (= inactive, so the 0 in the code)
> if mmc is powered off. That make bluetooth usable without wifi on
> gta04
> 
> Signed-off-by: Andreas Kemnade <andreas at kemnade.info>
> ---
> drivers/mmc/core/pwrseq_simple.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/mmc/core/pwrseq_simple.c b/drivers/mmc/core/pwrseq_simple.c
> index aba786d..6ac5a82 100644
> --- a/drivers/mmc/core/pwrseq_simple.c
> +++ b/drivers/mmc/core/pwrseq_simple.c
> @@ -69,7 +69,7 @@ static void mmc_pwrseq_simple_power_off(struct mmc_host *host)
> 	struct mmc_pwrseq_simple *pwrseq = container_of(host->pwrseq,
> 					struct mmc_pwrseq_simple, pwrseq);
> 
> -	mmc_pwrseq_simple_set_gpios_value(pwrseq, 1);
> +	mmc_pwrseq_simple_set_gpios_value(pwrseq, 0);
> 
> 	if (!IS_ERR(pwrseq->ext_clk) && pwrseq->clk_enabled) {
> 		clk_disable_unprepare(pwrseq->ext_clk);
> -- 
> 2.1.4
> 
> _______________________________________________
> http://projects.goldelico.com/p/gta04-kernel/
> Letux-kernel mailing list
> Letux-kernel at openphoenux.org
> http://lists.goldelico.com/mailman/listinfo.cgi/letux-kernel