linux-kernel - [PATCH] mmc: dw_mmc: Power on vqmmc in MMC_POWER_ON, not MMC_POWER

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Date:	Tue, 13 Jan 2015 15:58:44 -0800
From:	Doug Anderson <dianders@...omium.org>
To:	Jaehoon Chung <jh80.chung@...sung.com>,
	Seungwon Jeon <tgih.jun@...sung.com>,
	Ulf Hansson <ulf.hansson@...aro.org>
Cc:	Alim Akhtar <alim.akhtar@...sung.com>,
	Sonny Rao <sonnyrao@...omium.org>,
	Andrew Bresticker <abrestic@...omium.org>,
	Heiko Stuebner <heiko@...ech.de>, amstan@...omium.org,
	addy.ke@...k-chips.com, yuvaraj.cd@...il.com,
	Doug Anderson <dianders@...omium.org>, chris@...ntf.net,
	linux-mmc@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: [PATCH] mmc: dw_mmc: Power on vqmmc in MMC_POWER_ON, not MMC_POWER_UP

If we power up vqmmc in MMC_POWER_ON then we end up turning it on
before mmc_power_up() sets the signal voltage.  That's not so great
since we might be powering it up at the wrong voltage.

Note that this is how Yuvaraj originally coded things up in
<https://patchwork.kernel.org/patch/4401231/> but he changed it on my
suggestion.  Apparently I was wrong.

Reported-by: Alexandru M Stan <amstan@...omium.org>
Signed-off-by: Doug Anderson <dianders@...omium.org>
---
 drivers/mmc/host/dw_mmc.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
index 2e8abc8..4d2e3c2 100644
--- a/drivers/mmc/host/dw_mmc.c
+++ b/drivers/mmc/host/dw_mmc.c
@@ -1119,6 +1119,12 @@ static void dw_mci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
 				return;
 			}
 		}
+		set_bit(DW_MMC_CARD_NEED_INIT, &slot->flags);
+		regs = mci_readl(slot->host, PWREN);
+		regs |= (1 << slot->id);
+		mci_writel(slot->host, PWREN, regs);
+		break;
+	case MMC_POWER_ON:
 		if (!IS_ERR(mmc->supply.vqmmc) && !slot->host->vqmmc_enabled) {
 			ret = regulator_enable(mmc->supply.vqmmc);
 			if (ret < 0)
@@ -1127,10 +1133,6 @@ static void dw_mci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
 			else
 				slot->host->vqmmc_enabled = true;
 		}
-		set_bit(DW_MMC_CARD_NEED_INIT, &slot->flags);
-		regs = mci_readl(slot->host, PWREN);
-		regs |= (1 << slot->id);
-		mci_writel(slot->host, PWREN, regs);
 		break;
 	case MMC_POWER_OFF:
 		if (!IS_ERR(mmc->supply.vmmc))
-- 
2.2.0.rc0.207.ga3a616c

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