sdhci: avoid changing voltage needlessly
Because of granularity issues, sometimes we told the hardware to change
to the voltage we were already at. Rework the logic so this doesn't
happen.
Signed-off-by: Pierre Ossman <pierre@ossman.eu>
diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 9234be2..1432a35 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -1005,12 +1005,34 @@
{
u8 pwr;
- if (host->power == power)
+ if (power == (unsigned short)-1)
+ pwr = 0;
+ else {
+ switch (1 << power) {
+ case MMC_VDD_165_195:
+ pwr = SDHCI_POWER_180;
+ break;
+ case MMC_VDD_29_30:
+ case MMC_VDD_30_31:
+ pwr = SDHCI_POWER_300;
+ break;
+ case MMC_VDD_32_33:
+ case MMC_VDD_33_34:
+ pwr = SDHCI_POWER_330;
+ break;
+ default:
+ BUG();
+ }
+ }
+
+ if (host->pwr == pwr)
return;
- if (power == (unsigned short)-1) {
+ host->pwr = pwr;
+
+ if (pwr == 0) {
sdhci_writeb(host, 0, SDHCI_POWER_CONTROL);
- goto out;
+ return;
}
/*
@@ -1020,35 +1042,16 @@
if (!(host->quirks & SDHCI_QUIRK_SINGLE_POWER_WRITE))
sdhci_writeb(host, 0, SDHCI_POWER_CONTROL);
- pwr = SDHCI_POWER_ON;
-
- switch (1 << power) {
- case MMC_VDD_165_195:
- pwr |= SDHCI_POWER_180;
- break;
- case MMC_VDD_29_30:
- case MMC_VDD_30_31:
- pwr |= SDHCI_POWER_300;
- break;
- case MMC_VDD_32_33:
- case MMC_VDD_33_34:
- pwr |= SDHCI_POWER_330;
- break;
- default:
- BUG();
- }
-
/*
* At least the Marvell CaFe chip gets confused if we set the voltage
* and set turn on power at the same time, so set the voltage first.
*/
if ((host->quirks & SDHCI_QUIRK_NO_SIMULT_VDD_AND_POWER))
- sdhci_writeb(host, pwr & ~SDHCI_POWER_ON, SDHCI_POWER_CONTROL);
+ sdhci_writeb(host, pwr, SDHCI_POWER_CONTROL);
+
+ pwr |= SDHCI_POWER_ON;
sdhci_writeb(host, pwr, SDHCI_POWER_CONTROL);
-
-out:
- host->power = power;
}
/*****************************************************************************\