On Tue, 18 Dec 2018 at 16:54, Tony Lindgren <tony@xxxxxxxxxxx> wrote: > > Hi, > > * Ulf Hansson <ulf.hansson@xxxxxxxxxx> [181218 12:34]: > > Instead, it looks like what you need, is a way to keep track of > > whether the SDIO card, became power cycled or if it stayed powered on, > > when "ifconfig wlan0 up" is done. In case of a power cycle, you need > > to re-program the firmware, right? > > Yeah mostly. But we also need to ensure things do get powered down > properly after ifconfig wlan0 down :) IMO after ifconfig wlan0 down > returns, there should be no waiting needed. > > > Would it be possible to re-program the firmware, even if the SDIO card > > stayed powered-on? > > That might help for some cases, but the problem of how to ensure the > card is powered down after ifconfig wlan0 down returns still exists. Well, does the SDIO card really have to be powered down before "ifconfig wlan0 down" returns? If so, why? An option would be to call pm_runtime_get_sync() at "ifconfig wlan0 up" (I assume you already do that) and then re-program the firmware, even if the card hasn't been power cycled. Wouldn't that work? Or perhaps this is the problem you are encountering, that the FW can't be reprogrammed, unless the card has been power cycled? You can easily test that, by simply bumping the runtime usage count for the card device via sysfs, before doing the "ifconfig wlan0 up/down" thingy. > > > In regards to delays needed due to a capacitance. If that really is > > the case, that shall be the managed by the mmc core, as it's there the > > power cycle sequence is being done. As a matter of fact, you should be > > able to use drivers/mmc/core/pwrseq_simple.c and extend > > "power-off-delay-us" in the DTB for Hikey if that is needed. > > Hmm I do have a mostly done wlcore pwrseq driver here somewhere that > I have not had a chance to finish again. But that's not going to work > for a fix and needs updating of the related dts files too. Right. Let's see what we can figure out. Kind regards Uffe
