Hi, On Tue, Nov 12, 2019 at 4:14 AM Ulf Hansson <ulf.hansson@xxxxxxxxxx> wrote: > > > > diff --git a/drivers/net/wireless/marvell/mwifiex/sdio.c b/drivers/net/wireless/marvell/mwifiex/sdio.c > > > index 24c041dad9f6..2417c94c29c0 100644 > > > --- a/drivers/net/wireless/marvell/mwifiex/sdio.c > > > +++ b/drivers/net/wireless/marvell/mwifiex/sdio.c > > > @@ -444,6 +444,9 @@ static int mwifiex_sdio_suspend(struct device *dev) > > > return 0; > > > } > > > > > > + if (!adapter->is_adapter_up) > > > + return -EBUSY; > > > > I'm moderately concerned that there might be cases where firmware > > never got loaded but we could suspend/resume OK. ...and now we never > > will? I'm not familiar enough with the code to know if this is a real > > concern, so I guess we can do this and then see... > > There is a completion variable that is used to make sure the firmware > is loaded, before the mwifiex driver runs ->suspend|remove(). This is > needed, because during ->probe() the FW will be loaded asynchronously, > hence both mwifiex_sdio_remove() and mwifiex_sdio_suspend(), may be > called while waiting for the FW to be loaded. > > If a HW reset has been scheduled but not completed, which would be the > case if mmc_hw_reset() gets called after mmc_pm_notify() with a > PM_SUSPEND_PREPARE. This is because mmc_pm_notify() then disables the > rescan work, but then re-kicks/enables it at PM_POST_SUSPEND (after > the system has resumed). > > Returning -EBUSY, should allow the mmc rescan work to be completed > when the system have resumed. > > Of course, one could also considering using pm_wakeup_event(), in case > mmc_hw_reset() needed to schedule the reset, as to prevent the system > for suspending for a small amount of time. As to make sure the rescan > work, gets to run. But I am not sure that's needed here. I was more worried that we could get into a state where we'd return EBUSY forever, but I think I've convinced myself that this isn't possible. If we fail to load things then the adapter variable will be freed anyway. > Finally, if you want to verify that the above system suspend path > works fine, you could change the call to "_mmc_detect_change(host, 0, > false)" in mmc_sdio_hw_reset(), into "_mmc_detect_change(host, > msecs_to_jiffies(30000), false)", in patch3. > > This should leave you a 30s window of where you can try to system > suspend the platform, while also waiting for the scheduled reset to be > completed. It worked. https://pastebin.com/NdsvAdE8
