Ulf Hansson <ulf.hansson@xxxxxxxxxx> 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@xxxxxxxxxx>
> Tested-by: Tony Lindgren <tony@xxxxxxxxxxx>
> Tested-by: Anders Roxell <anders.roxell@xxxxxxxxxx>
> Signed-off-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx>
Patch applied to wireless-drivers.git, thanks.
13e62626c578 wlcore: sdio: Fixup power on/off sequence
--
https://patchwork.kernel.org/patch/10765781/
https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches
