Seungwon, On Thu, Jun 26, 2014 at 3:30 AM, Seungwon Jeon <tgih.jun@xxxxxxxxxxx> wrote: > Hi Doug, > > On Thu, June 26, 2014, Doug Anderson wrote: >> Seungwon, >> >> On Wed, Jun 25, 2014 at 4:18 AM, Seungwon Jeon <tgih.jun@xxxxxxxxxxx> wrote: >> >> >> + case MMC_POWER_ON: >> >> >> + if (!IS_ERR(mmc->supply.vqmmc) && >> >> >> + !test_bit(DW_MMC_IO_POWERED, &slot->flags)) { >> > You can use regulator_is_enabled() instead of flag bit, DW_MMC_IO_POWERED. >> >> I'd be a little worried about regulator_is_enabled() since regulators >> are reference counted. What if someone else is sharing this >> regulator? The regulator might happen to be enabled when you check it >> but unless you add your own dw_mmc reference count they might turn it >> off. > Cool, that's a possibility. Some assumption may need. > If mmc's core can guarantee its balance, I think we don't need to consider some flag. I notice that the mmc core seems to keep a flag itself for vdd (the mmc->regulator_enabled flag). That would imply that the core thought it was important to have the extra flag and that we should keep our own flag for vqmmc. -Doug -- 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