From mboxrd@z Thu Jan 1 00:00:00 1970 From: tgih.jun@samsung.com (Seungwon Jeon) Date: Thu, 26 Jun 2014 19:30:52 +0900 Subject: [PATCH 1/3] mmc: dw_mmc: use mmc_regulator_get_supply to handle regulators In-Reply-To: References: <1403520321-2431-1-git-send-email-yuvaraj.cd@samsung.com> <1403520321-2431-2-git-send-email-yuvaraj.cd@samsung.com> <53AA3F78.3080804@samsung.com> <001201cf9067$3c5b2070$b5116150$%jun@samsung.com> Message-ID: <004f01cf9129$b4ac9690$1e05c3b0$%jun@samsung.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hi Doug, On Thu, June 26, 2014, Doug Anderson wrote: > Seungwon, > > On Wed, Jun 25, 2014 at 4:18 AM, Seungwon Jeon 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. Thanks, Seungwon Jeon > > > Important thing is that if powering vmmc failed at MMC_POWER_UP, vqmmc should not be powered. > > Good point. > -- > To unsubscribe from this list: send the line "unsubscribe linux-mmc" in > the body of a message to majordomo at vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html