[PATCH 3/7] ARM: LPC32xx: Remove wrong re-initialization of MMC clock register

From: Roland Stigge
Date: Sun Jun 24 2012 - 09:48:45 EST


This patch fixes a bug, (wrongfully) resetting the value of
LPC32XX_CLKPWR_MS_CTRL back to its initial contents (after careful setup). This
was discovered only with a board/bootloader combination (EA3250) where the
contents of the respective register wasn't already at the correct value on
Linux boot.

Signed-off-by: Roland Stigge <stigge@xxxxxxxxx>
Acked-by: Alexandre Pereira da Silva <aletes.xgr@xxxxxxxxx>

---
arch/arm/mach-lpc32xx/clock.c | 10 +++-------
1 file changed, 3 insertions(+), 7 deletions(-)

--- linux-2.6.orig/arch/arm/mach-lpc32xx/clock.c
+++ linux-2.6/arch/arm/mach-lpc32xx/clock.c
@@ -871,7 +871,7 @@ static unsigned long mmc_round_rate(stru

static int mmc_set_rate(struct clk *clk, unsigned long rate)
{
- u32 oldclk, tmp;
+ u32 tmp;
unsigned long prate, div, crate = mmc_round_rate(clk, rate);

prate = clk->parent->get_rate(clk->parent);
@@ -879,16 +879,12 @@ static int mmc_set_rate(struct clk *clk,
div = prate / crate;

/* The MMC clock must be on when accessing an MMC register */
- oldclk = __raw_readl(LPC32XX_CLKPWR_MS_CTRL);
- __raw_writel(oldclk | LPC32XX_CLKPWR_MSCARD_SDCARD_EN,
- LPC32XX_CLKPWR_MS_CTRL);
tmp = __raw_readl(LPC32XX_CLKPWR_MS_CTRL) &
~LPC32XX_CLKPWR_MSCARD_SDCARD_DIV(0xf);
- tmp |= LPC32XX_CLKPWR_MSCARD_SDCARD_DIV(div);
+ tmp |= LPC32XX_CLKPWR_MSCARD_SDCARD_DIV(div) |
+ LPC32XX_CLKPWR_MSCARD_SDCARD_EN;
__raw_writel(tmp, LPC32XX_CLKPWR_MS_CTRL);

- __raw_writel(oldclk, LPC32XX_CLKPWR_MS_CTRL);
-
return 0;
}

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