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From: Seth Forshee <seth.forshee@gmail.com>
To: linux-omap@vger.kernel.org
Subject: PRCM_CLKSRC_CTRL bits set incorrectly in omap2_en_osc_ck
Date: Thu, 24 Apr 2008 20:56:56 -0500	[thread overview]
Message-ID: <20080425015654.GA7122@ubuntu-workstation> (raw)

On my OMAP2430 board I was seeing the contents of DRAM become corrupted
shortly after the kernel started.  I tracked this down to
omap2_enable_osc_ck().  I think this function is intended to only clear
the bits in OMAP_AUTOEXTCLKMODE_MASK, but it has the side-effect of
setting all of the other bits in the register.  This includes setting
some fields to reserved values.

I'm not 100% sure whether the problem is with omap2_enable_osc_ck() or
prm_rmw_reg_bits() (maybe this should be masking off any bits not set in
mask), but based on what I see elsewhere I think that
omap2_enable_osc_ck() is to blame.  If this is the case, the patch below
fixes the problem.


----------
From: Seth Forshee <seth.forshee@gmail.com>
Subject: [PATCH] ARM: OMAP2: Set PRCM_CLKSRC_CTRL correctly in omap2_enable_osc_ck

This patch fixes an incorrect use of prm_rmw_reg_bits() in
omap2_enable_osc_ck() which is changing bits in PRCM_CLKSRC_CTRL
that are unrelated to the function it is performing.

Signed-off-by: Seth Forshee <seth.forshee@gmail.com>
---
 arch/arm/mach-omap2/clock24xx.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/arch/arm/mach-omap2/clock24xx.c b/arch/arm/mach-omap2/clock24xx.c
index 9b7fd15..e7968e7 100644
--- a/arch/arm/mach-omap2/clock24xx.c
+++ b/arch/arm/mach-omap2/clock24xx.c
@@ -78,7 +78,7 @@ static u32 omap2_get_dpll_rate_24xx(struct clk *tclk)
 static int omap2_enable_osc_ck(struct clk *clk)
 {
 
-	prm_rmw_reg_bits(OMAP_AUTOEXTCLKMODE_MASK, ~OMAP_AUTOEXTCLKMODE_MASK,
+	prm_rmw_reg_bits(OMAP_AUTOEXTCLKMODE_MASK, 0,
 			 OMAP24XX_PRCM_CLKSRC_CTRL);
 
 	return 0;

             reply	other threads:[~2008-04-25  1:57 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-04-25  1:56 Seth Forshee [this message]
2008-04-25  8:01 ` PRCM_CLKSRC_CTRL bits set incorrectly in omap2_en_osc_ck Paul Walmsley
2008-04-25 17:44   ` Tony Lindgren

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