Patchwork [1/4] sdhci-of: Fix SD clock calculation

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Submitter Anton Vorontsov
Date Aug. 7, 2009, 4:40 p.m.
Message ID <20090807164057.GA13464@oksana.dev.rtsoft.ru>
Download mbox | patch
Permalink /patch/30941/
State Superseded
Delegated to: Kumar Gala
Headers show

Comments

Anton Vorontsov - Aug. 7, 2009, 4:40 p.m.
Linear divisor's values in a register start at 0 (zero means
"divide by 1"). Before this patch the code didn't account that
fact, so SD cards were running underclocked.

Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
---
 drivers/mmc/host/sdhci-of.c |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)

Patch

diff --git a/drivers/mmc/host/sdhci-of.c b/drivers/mmc/host/sdhci-of.c
index 9088443..92b5667 100644
--- a/drivers/mmc/host/sdhci-of.c
+++ b/drivers/mmc/host/sdhci-of.c
@@ -136,6 +136,7 @@  static void esdhc_set_clock(struct sdhci_host *host, unsigned int clock)
 	}
 
 	pre_div >>= 1;
+	div--;
 
 	setbits32(host->ioaddr + ESDHC_SYSTEM_CONTROL, ESDHC_CLOCK_IPGEN |
 		  ESDHC_CLOCK_HCKEN | ESDHC_CLOCK_PEREN |