Merge tag 'mvebu-dt-5.8-1' of git://git.infradead.org/linux-mvebu into arm/dt

[linux-2.6-microblaze.git] / drivers / mmc / host / sdhci-xenon.c

diff --git a/drivers/mmc/host/sdhci-xenon.c b/drivers/mmc/host/sdhci-xenon.c
index 1dea1ba..4703cd5 100644 (file)
--- a/drivers/mmc/host/sdhci-xenon.c
+++ b/drivers/mmc/host/sdhci-xenon.c
@@ -235,6 +235,16 @@ static void xenon_voltage_switch(struct sdhci_host *host)
 {
        /* Wait for 5ms after set 1.8V signal enable bit */
        usleep_range(5000, 5500);
+
+       /*
+        * For some reason the controller's Host Control2 register reports
+        * the bit representing 1.8V signaling as 0 when read after it was
+        * written as 1. Subsequent read reports 1.
+        *
+        * Since this may cause some issues, do an empty read of the Host
+        * Control2 register here to circumvent this.
+        */
+       sdhci_readw(host, SDHCI_HOST_CONTROL2);
 }
 
 static const struct sdhci_ops sdhci_xenon_ops = {