From: Anton Vorontsov <avorontsov@ru.mvista.com>
Date: Tue, 22 Sep 2009 23:45:10 +0000 (-0700)
Subject: sdhci-of: fix SD clock calculation
X-Git-Tag: archive/raspbian/4.9.13-1+rpi1~10^2~21002
X-Git-Url: https://dgit.raspbian.org/%22http://www.example.com/cgi/%22/%22http:/www.example.com/cgi/%22?a=commitdiff_plain;h=1e5df7525d0705dfbfded0c10a7b87b0a754a35d;p=linux-4.9.git

sdhci-of: fix SD clock calculation

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>
Cc: Pierre Ossman <pierre@ossman.eu>
Cc: Kumar Gala <galak@kernel.crashing.org>
Cc: David Vrabel <david.vrabel@csr.com>
Cc: Ben Dooks <ben@fluff.org>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: <linux-mmc@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---

diff --git a/drivers/mmc/host/sdhci-of.c b/drivers/mmc/host/sdhci-of.c
index 1e8aa590bb39..2b0756934f49 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 |