Make the routine for setting power compliant with the specification.

Certain ENE chips seem to be sufficiently non-compliant that they don't like
this change; however, the single-power-write quirk should be enough to handle
them (and is, in the case of at least one such device).

Not-yet-signed-off-by: Darren Salt <linux@youmustbejoking.demon.co.uk>

diff -ur linux-2.6.20-rc6.orig/drivers/mmc/sdhci.c linux-2.6.20-rc6/drivers/mmc/sdhci.c
--- linux-2.6.20-rc6.orig/drivers/mmc/sdhci.c	2007-02-02 20:04:54.000000000 +0000
+++ linux-2.6.20-rc6/drivers/mmc/sdhci.c	2007-02-02 20:14:28.000000000 +0000
@@ -691,28 +691,31 @@
 	if ((host->chip->quirks & SDHCI_QUIRK_SINGLE_POWER_WRITE) == 0)
 		writeb(0, host->ioaddr + SDHCI_POWER_CONTROL);
 
-	pwr = SDHCI_POWER_ON;
-
 	switch (power) {
 	case MMC_VDD_170:
 	case MMC_VDD_180:
 	case MMC_VDD_190:
-		pwr |= SDHCI_POWER_180;
+		pwr = SDHCI_POWER_180;
 		break;
 	case MMC_VDD_290:
 	case MMC_VDD_300:
 	case MMC_VDD_310:
-		pwr |= SDHCI_POWER_300;
+		pwr = SDHCI_POWER_300;
 		break;
 	case MMC_VDD_320:
 	case MMC_VDD_330:
 	case MMC_VDD_340:
-		pwr |= SDHCI_POWER_330;
+		pwr = SDHCI_POWER_330;
 		break;
 	default:
 		BUG();
 	}
 
+	if ((host->chip->quirks & SDHCI_QUIRK_SINGLE_POWER_WRITE) == 0)
+		writeb(pwr, host->ioaddr + SDHCI_POWER_CONTROL);
+
+	pwr |= SDHCI_POWER_ON;
+
 out:
 	writeb(pwr, host->ioaddr + SDHCI_POWER_CONTROL);