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Date:	Tue, 14 Oct 2014 09:39:12 -0700
From:	Doug Anderson <>
To:	Ulf Hansson <>,
	Seungwon Jeon <>,
	Jaehoon Chung <>
Cc:	Addy Ke <>,
	Sonny Rao <>,
	Alim Akhtar <>,
	Andrew Bresticker <>,
	Doug Anderson <>,,,,,,
Subject: [PATCH] mmc: dw_mmc: rockchip: Don't recalc the clock when it goes off

The "set_ios" function is called with a clock of 0 when the clock is
turning off.  There's no reason to go through all the extra Rockchip
logic (whose goal is to make sure DIV is 0 or 1) in that case.  The
Rockchip logic happened to work because the CCF will pick the lowest
possible rate when you ask it for a clock of 0, but it's silly to go
through all the remuxing and adjusting for no reason.

Signed-off-by: Doug Anderson <>
 drivers/mmc/host/dw_mmc-rockchip.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/mmc/host/dw_mmc-rockchip.c b/drivers/mmc/host/dw_mmc-rockchip.c
index f0c2cb1..bbb4ec3 100644
--- a/drivers/mmc/host/dw_mmc-rockchip.c
+++ b/drivers/mmc/host/dw_mmc-rockchip.c
@@ -37,6 +37,9 @@ static void dw_mci_rk3288_set_ios(struct dw_mci *host, struct mmc_ios *ios)
 	unsigned int cclkin;
 	u32 bus_hz;
+	if (ios->clock == 0)
+		return;
 	 * cclkin: source clock of mmc controller
 	 * bus_hz: card interface clock generated by CLKGEN

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