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SubjectRe: [PATCH V2] wlcore: sdio: Fixup power on/off sequence
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On 16.01.19 12:37, Ulf Hansson wrote:
> During "wlan-up", we are programming the FW into the WiFi-chip. However,
> re-programming the FW doesn't work, unless a power cycle of the WiFi-chip
> is made in-between the programmings.
>
> To conform to this requirement and to fix the regression in a simple way,
> let's start by allowing that the SDIO card (WiFi-chip) may stay powered on
> (runtime resumed) when wl12xx_sdio_power_off() returns. The intent with the
> current code is to treat this scenario as an error, but unfortunate this
> doesn't work as expected, so let's fix this.
>
> The other part is to guarantee that a power cycle of the SDIO card has been
> completed when wl12xx_sdio_power_on() returns, as to allow the FW
> programming to succeed. However, relying solely on runtime PM to deal with
> this isn't sufficient. For example, userspace may prevent runtime suspend
> via sysfs for the device that represents the SDIO card, leading to that the
> mmc core also keeps it powered on. For this reason, let's instead do a
> brute force power cycle in wl12xx_sdio_power_on().
>
> Fixes: 728a9dc61f13 ("wlcore: sdio: Fix flakey SDIO runtime PM handling")
> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
> ---
>
> Changes in v2:
> - Keep the SDIO host claimed when calling mmc_hw_reset().
> - Add a fixes tag.
> ---
> drivers/net/wireless/ti/wlcore/sdio.c | 15 +++++++--------
> 1 file changed, 7 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/net/wireless/ti/wlcore/sdio.c b/drivers/net/wireless/ti/wlcore/sdio.c
> index bd10165d7eec..4d4b07701149 100644
> --- a/drivers/net/wireless/ti/wlcore/sdio.c
> +++ b/drivers/net/wireless/ti/wlcore/sdio.c
> @@ -164,6 +164,12 @@ static int wl12xx_sdio_power_on(struct wl12xx_sdio_glue *glue)
> }
>
> sdio_claim_host(func);
> + /*
> + * To guarantee that the SDIO card is power cycled, as required to make
> + * the FW programming to succeed, let's do a brute force HW reset.
> + */
> + mmc_hw_reset(card->host);
> +
> sdio_enable_func(func);
> sdio_release_host(func);
>
> @@ -174,20 +180,13 @@ static int wl12xx_sdio_power_off(struct wl12xx_sdio_glue *glue)
> {
> struct sdio_func *func = dev_to_sdio_func(glue->dev);
> struct mmc_card *card = func->card;
> - int error;
>
> sdio_claim_host(func);
> sdio_disable_func(func);
> sdio_release_host(func);
>
> /* Let runtime PM know the card is powered off */
> - error = pm_runtime_put(&card->dev);
> - if (error < 0 && error != -EBUSY) {
> - dev_err(&card->dev, "%s failed: %i\n", __func__, error);
> -
> - return error;
> - }
> -
> + pm_runtime_put(&card->dev);
> return 0;
> }
>
>

Just tested on both HiKey (620) and Ultra96 but it fails to fix the issue on
both. I'm getting

wl1271_sdio: probe of mmc2:0001:1 failed with error -16

during boot again, and the interface is not available.

Jan

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