[...] >>>> 2) system PM (disable?) >>> >>> System pm does mmc_power_off() which calls mmc_set_initial_state() >> >> At System PM other commands will be sent to put the card into sleep >> state. For example CMD5. These commands are invoked prior >> mmc_power_off() is called. > > You can't do *any* commands after CMD5 except CMD0 or another CMD5 to wake up. > > So if you want to wake-up from sleep, then you need to hold re-tuning, but > that is not what is happening at the moment. So then we need to fix this. Also, it seems like disabling the re-tuning timer would also be the proper thing to do, thus we should rather do disable instead of hold/release. > >> >> In the SDIO case, mmc_power_off() might not even be called at all, >> since SDIO func drivers might have enabled MMC_PM_KEEP_POWER. > > If the card is not going to be re-initialized then disabling is not necessary. I don't want the re-tuning timer to be running, thus it seems like we should do disable. Right? > >> >>> >>>> 3) runtime PM (disable?) >>> >>> If the card powers off then mmc_set_initial_state() will called. >> >> Again that's too late, since for example the CMD5 might have been sent >> before this. > > CMD5 is only used by _mmc_suspend() > > Yes if it were used elsewhere then re-tuning would have to be held, which is > why I added a comment before mmc_sleep() > > /* If necessary, callers must hold re-tuning */ > static int mmc_sleep(struct mmc_host *host) > I don't follow here. Why would we like to allow a re-tuning to be done in this part of the system PM phase? It doesn't make sense to me. >> >>> >>> For anything else the card might be doing, the mmc_retune_hold() / >>> mmc_retune_release() functions are used. >>> >>>> 4) reset (?) >>> >>> Reset goes through mmc_set_initial_state() >> >> In the mmc case, CMD13 is sent prior that. Shouldn't we hold re-tune >> during that period? > > If reset happens, then the next command will fail, whether it is re-tuning > or CMD13, so no different. That depends on how each an every host has implemented their tuning mechanism. CMD13 is more light weight, so I believe we should hold re-tune to make sure we do the CMD13 and fail quickly. > > If reset doesn't happen, then it is no different to normal operations. > Kind regards Uffe -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
