Re: SDIO wifi card is not detected with 4.5-rc kernels

[Michael Turquette <mturquette@baylibre.com>]

+ linux-clk

On Wed, Feb 17, 2016 at 2:11 PM, Russell King - ARM Linux
<linux@arm.linux.org.uk> wrote:
> On Wed, Feb 17, 2016 at 02:03:47PM -0800, Michael Turquette wrote:
>> Hi Russell, all,
>>
>> On Wed, Feb 17, 2016 at 1:18 PM, Russell King - ARM Linux
>> <linux@arm.linux.org.uk> wrote:
>> > [   52.175162] match->alloc failed: -517
>> > [   52.178874] sdhci-esdhc-imx 2190000.usdhc: mmc_of_parse failed: -517
>> > [   52.185271] sdhci-esdhc-imx 2190000.usdhc: imx probe failed
>> >
>> > -517 is -EPROBE_DEFER, and looking at what's in the clk_summary
>> > debugfs file, my guess is that the clk_sdio gpio-gate-clock is not
>> > being registered for some unknown reason.  Adding Michael - any
>> > ideas why gpio-gate-clock has stopped working between 4.4 and
>> > present?
>>
>> So you are missing a gpio-gate clk in v4.5-rc1 that is present in v4.4?
>
> It seems so.
>
> arch/arm/boot/dts/imx6qdl-microsom.dtsi has:
>
>         clk_sdio: sdio-clock {
>                 compatible = "gpio-gate-clock";
>                 #clock-cells = <0>;
>                 pinctrl-names = "default";
>                 pinctrl-0 = <&pinctrl_microsom_brcm_osc>;
>                 enable-gpios = <&gpio5 5 GPIO_ACTIVE_HIGH>;
>         };
>
> and if I boot the kernel with that:
>
> # grep sdio /sys/kernel/debug/clk/clk_summary
> #
>
> If I look at a system with v4.4 booted:
>
> # grep sdio /sys/kernel/debug/clk/clk_summary
>  sdio-clock                               1            1           0          0    0
>
> So, this appears to be a regression.
>
>> There isn't much to go on here, but mmc_of_parse can fail with
>> mmc_gpiod_request_cd and mmc_gpiod_request_ro, in addition to
>> mmc_pwrseq_alloc. I didn't follow the call chain to see if either of
>> those are capable of spitting out -EPROBE_DEFER.
>
> Yes, there's other possible failures, but:
>
> [   52.175162] match->alloc failed: -517
>
> points to the mmc_pwrseq_alloc stuff - because that message is printed
> from inside there.  The pwrseq stuff consists of:
>
>         usdhc1_pwrseq: usdhc1_pwrseq {
>                 compatible = "mmc-pwrseq-simple";
>                 reset-gpios = <&gpio5 26 GPIO_ACTIVE_LOW>,
>                               <&gpio6 0 GPIO_ACTIVE_LOW>;
>                 clocks = <&clk_sdio>;
>                 clock-names = "ext_clock";
>         };
>
> some GPIOs, and that clock - the GPIOs are definitely present, and the
> sdio clock is clearly missing from clk_summary.
>
>> clk patches affecting the gpio-gate from 4.4 to 4.5-rc1 are:
>>
>> 7ed88aa clk: fix clk-gpio.c with optional clock= DT property
>> 0b2e788 clk: gpio: handle error codes for of_clk_get_parent_count()
>> c76eb11 clk: gpio: fix memory leak
>> f66541b clk: gpio: Get parent clk names in of_gpio_clk_setup()
>>
>> Anyone that can reproduce, care to bisect?
>
> This isn't -next, this is 4.5-rc4 that I'm seeing the failure on.
> 4.5-rc4 still has clk-gpio.c with:
>
> CLK_OF_DECLARE(gpio_gate_clk, "gpio-gate-clock", of_gpio_gate_clk_setup);

Right, the patches I posted above are v4.4..v4.5-rc1 based on your
original email stating you saw the regression when rebasing onto -rc1.
The platform_driver patch was just a random piece of info and it is
not yet landed in linux-next anyways.

Probably the best approach is for someone that can reproduce the
failure to either bisect or try to selectively revert the patches I
list above. There are multiple potential culprits in that list of
patches, as several of them touch the setup/registration functions in
clk-gpio.c.

Regards,
Mike

>
> Annoyingly, it's silent in the boot log about what's going on wrt
> this clock.