Hi Marc,
On Mon, Mar 13, 2023 at 6:09 PM Marc Gonzalez <marc.w.gonzalez@xxxxxxx> wrote:
[...]
> > Wrapping mmc_send_io_op_cond() in a loop
> > makes it work on the second try.
>
> Almost there, I think, I hope :)
>
> DT prop "post-power-on-delay-ms" looks like what I needed all along.
> It exists both for host (default 10 ms) and for pwrseq_simple (default 0 apparently).
I think you're on the right track here!
[...]
> QUESTION:
> It's not clear to me why we sleep twice for host->ios.power_delay_ms?
I'm not sure but I think host->ios.power_delay_ms is independent from
the post-power-on-delay-ms property of "mmc-pwrseq-simple".
> Looks like all I need is to add post-power-on-delay-ms = <100>; to
>
> sdio_pwrseq: sdio-pwrseq {
> compatible = "mmc-pwrseq-simple";
> reset-gpios = <&gpio GPIOX_6 GPIO_ACTIVE_LOW>;
> clocks = <&wifi32k>;
> clock-names = "ext_clock";
> };
I found the following code in the vendor RTL8822CS driver [0].
Simplified version:
for (i = 0; i <= 50; i++) {
msleep(10);
if (sdhci_device_attached())
break;
}
(so a delay of up to 500ms)
Also I found this code [1] in the same repo:
mmc_pm_gpio_ctrl("rtl8189es_vdd_en", 1);
udelay(100);
mmc_pm_gpio_ctrl("rtl8189es_vcc_en", 1);
udelay(50);
So like I said above: I think you're going in the right direction!
Best regards,
Martin
[0] https://github.com/chewitt/RTL8822CS/blob/main/platform/platform_sprd_sdio.c#L55-L62
[1] https://github.com/chewitt/RTL8822CS/blob/main/platform/platform_ARM_SUNxI_sdio.c#L35-L43
