mmc: sdhci: Do not use spin lock in set_ios paths

The spin lock is not necessary in set_ios. Anything that is racing with
changes to the I/O state is already broken. The mmc core already provides
synchronization via "claiming" the host. So remove spin_lock and friends
from sdhci_set_ios and related callbacks.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Tested-by: Ludovic Desroches <ludovic.desroches@microchip.com>

drivers/mmc/host/sdhci-msm.c

@@ -991,12 +991,8 @@ static void sdhci_msm_set_uhs_signaling(struct sdhci_host *host,
 		mmc_hostname(host->mmc), host->clock, uhs, ctrl_2);
 	sdhci_writew(host, ctrl_2, SDHCI_HOST_CONTROL2);
 
-	spin_unlock_irq(&host->lock);
-
 	if (mmc->ios.timing == MMC_TIMING_MMC_HS400)
 		sdhci_msm_hs400(host, &mmc->ios);
-
-	spin_lock_irq(&host->lock);
 }
 
 static void sdhci_msm_voltage_switch(struct sdhci_host *host)
@@ -1089,13 +1085,9 @@ static void sdhci_msm_set_clock(struct sdhci_host *host, unsigned int clock)
 		goto out;
 	}
 
-	spin_unlock_irq(&host->lock);
-
 	sdhci_msm_hc_select_mode(host);
 
 	msm_set_clock_rate_for_bus_mode(host, clock);
-
-	spin_lock_irq(&host->lock);
 out:
 	__sdhci_msm_set_clock(host, clock);
 }

drivers/mmc/host/sdhci-of-arasan.c

@@ -194,9 +194,7 @@ static void sdhci_arasan_set_clock(struct sdhci_host *host, unsigned int clock)
 			 * through low speeds without power cycling.
 			 */
 			sdhci_set_clock(host, host->max_clk);
-			spin_unlock_irq(&host->lock);
 			phy_power_on(sdhci_arasan->phy);
-			spin_lock_irq(&host->lock);
 			sdhci_arasan->is_phy_on = true;
 
 			/*
@@ -215,18 +213,14 @@ static void sdhci_arasan_set_clock(struct sdhci_host *host, unsigned int clock)
 	}
 
 	if (ctrl_phy && sdhci_arasan->is_phy_on) {
-		spin_unlock_irq(&host->lock);
 		phy_power_off(sdhci_arasan->phy);
-		spin_lock_irq(&host->lock);
 		sdhci_arasan->is_phy_on = false;
 	}
 
 	sdhci_set_clock(host, clock);
 
 	if (ctrl_phy) {
-		spin_unlock_irq(&host->lock);
 		phy_power_on(sdhci_arasan->phy);
-		spin_lock_irq(&host->lock);
 		sdhci_arasan->is_phy_on = true;
 	}
 }

drivers/mmc/host/sdhci-of-at91.c

@@ -98,9 +98,7 @@ static void sdhci_at91_set_power(struct sdhci_host *host, unsigned char mode,
 	if (!IS_ERR(host->mmc->supply.vmmc)) {
 		struct mmc_host *mmc = host->mmc;
 
-		spin_unlock_irq(&host->lock);
 		mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, vdd);
-		spin_lock_irq(&host->lock);
 	}
 	sdhci_set_power_noreg(host, mode, vdd);
 }

drivers/mmc/host/sdhci-pci-core.c

@@ -484,8 +484,6 @@ static void sdhci_intel_set_power(struct sdhci_host *host, unsigned char mode,
 	if (mode == MMC_POWER_OFF)
 		return;
 
-	spin_unlock_irq(&host->lock);
-
 	/*
 	 * Bus power might not enable after D3 -> D0 transition due to the
 	 * present state not yet having propagated. Retry for up to 2ms.
@@ -498,8 +496,6 @@ static void sdhci_intel_set_power(struct sdhci_host *host, unsigned char mode,
 		reg |= SDHCI_POWER_ON;
 		sdhci_writeb(host, reg, SDHCI_POWER_CONTROL);
 	}
-
-	spin_lock_irq(&host->lock);
 }
 
 static const struct sdhci_ops sdhci_intel_byt_ops = {

drivers/mmc/host/sdhci-pxav3.c

@@ -323,11 +323,8 @@ static void pxav3_set_power(struct sdhci_host *host, unsigned char mode,
 	if (host->pwr == 0)
 		vdd = 0;
 
-	if (!IS_ERR(mmc->supply.vmmc)) {
-		spin_unlock_irq(&host->lock);
+	if (!IS_ERR(mmc->supply.vmmc))
 		mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, vdd);
-		spin_lock_irq(&host->lock);
-	}
 }
 
 static const struct sdhci_ops pxav3_sdhci_ops = {

drivers/mmc/host/sdhci-s3c.c

@@ -190,9 +190,7 @@ static unsigned int sdhci_s3c_consider_clock(struct sdhci_s3c *ourhost,
 	 * speed possible with selected clock source and skip the division.
 	 */
 	if (ourhost->no_divider) {
-		spin_unlock_irq(&ourhost->host->lock);
 		rate = clk_round_rate(clksrc, wanted);
-		spin_lock_irq(&ourhost->host->lock);
 		return wanted - rate;
 	}
 
@@ -389,9 +387,7 @@ static void sdhci_cmu_set_clock(struct sdhci_host *host, unsigned int clock)
 	clk &= ~SDHCI_CLOCK_CARD_EN;
 	sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL);
 
-	spin_unlock_irq(&host->lock);
 	ret = clk_set_rate(ourhost->clk_bus[ourhost->cur_clk], clock);
-	spin_lock_irq(&host->lock);
 	if (ret != 0) {
 		dev_err(dev, "%s: failed to set clock rate %uHz\n",
 			mmc_hostname(host->mmc), clock);

drivers/mmc/host/sdhci.c

@@ -1361,9 +1361,7 @@ void sdhci_enable_clk(struct sdhci_host *host, u16 clk)
 			sdhci_dumpregs(host);
 			return;
 		}
-		spin_unlock_irq(&host->lock);
 		udelay(10);
-		spin_lock_irq(&host->lock);
 	}
 
 	clk |= SDHCI_CLOCK_CARD_EN;
@@ -1392,9 +1390,7 @@ static void sdhci_set_power_reg(struct sdhci_host *host, unsigned char mode,
 {
 	struct mmc_host *mmc = host->mmc;
 
-	spin_unlock_irq(&host->lock);
 	mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, vdd);
-	spin_lock_irq(&host->lock);
 
 	if (mode != MMC_POWER_OFF)
 		sdhci_writeb(host, SDHCI_POWER_ON, SDHCI_POWER_CONTROL);
@@ -1574,16 +1570,12 @@ EXPORT_SYMBOL_GPL(sdhci_set_uhs_signaling);
 static void sdhci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
 {
 	struct sdhci_host *host = mmc_priv(mmc);
-	unsigned long flags;
 	u8 ctrl;
 
 	if (ios->power_mode == MMC_POWER_UNDEFINED)
 		return;
 
-	spin_lock_irqsave(&host->lock, flags);
-
 	if (host->flags & SDHCI_DEVICE_DEAD) {
-		spin_unlock_irqrestore(&host->lock, flags);
 		if (!IS_ERR(mmc->supply.vmmc) &&
 		    ios->power_mode == MMC_POWER_OFF)
 			mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, 0);
@@ -1729,7 +1721,6 @@ static void sdhci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
 		sdhci_do_reset(host, SDHCI_RESET_CMD | SDHCI_RESET_DATA);
 
 	mmiowb();
-	spin_unlock_irqrestore(&host->lock, flags);
 }
 
 static int sdhci_get_cd(struct mmc_host *mmc)