[PATCH] mmc: dw_mmc: rockchip: Don't recalc the clock when it goes off

[Doug Anderson]

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 <***@chromium.org>
---
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

[Jaehoon Chung]

Hi, Doug.

It looks good to me.

Post by Doug Anderson
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.
---
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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