If there is no vqmmc, real voltage should not change.
Then it needs to maintain the previous status for UHS_REG register.
It means that it doesn't need to set any bit.
Signed-off-by: Jaehoon Chung <jh80.chung@xxxxxxxxxxx>
---
drivers/mmc/host/dw_mmc.c | 12 ++++++++++++
1 file changed, 12 insertions(+)
diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
index 28602cc..6bd8018 100644
--- a/drivers/mmc/host/dw_mmc.c
+++ b/drivers/mmc/host/dw_mmc.c
@@ -1418,7 +1418,19 @@ static int dw_mci_switch_voltage(struct mmc_host *mmc, struct mmc_ios *ios)
ret, uhs & v18 ? "1.8" : "3.3");
return -EAGAIN;
}
+ } else {
+ /*
+ * If there isn't vqmmc, it should fail to switch voltage.
+ * Then it needs to maintain the previous status.
+ * If ios->signal_voltage is 3.3v, it means that previous
+ * voltages was 1.8v.
+ */
+ if (ios->signal_voltage == MMC_SIGNAL_VOLTAGE_330)
+ uhs |= v18;
+ else
+ uhs &= ~v18;
}
+
mci_writel(host, UHS_REG, uhs);
return 0;
--
1.9.1
--
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