[PATCH 01/20] OMAP3: wait on IDLEST after enabling USBTLL fclk

Paul Walmsley paul at pwsan.com
Fri Jul 2 11:29:10 EDT 2010


From: Anand Gadiyar <gadiyar at ti.com>

We need to wait on the IDLEST bit after the clocks are enabled
before attempting to access any register.

Currently, the USBTLL i-clock ops uses the clkops_omap2_dflt_wait,
while the USBTLL f-clock ops uses clkops_omap2_dflt. If the
i-clock is enabled first, the clkops_omap2_dflt_wait is
short-circuited as the companion f-clock is not enabled.
This can cause a data abort if the IDLEST has not transitioned,
and we try to access a USBTLL register.

Since the USBTLL i-clock and f-clock could be enabled in any order,
this is a bug. Fix it by changing the clkops for the f-clock.

Signed-off-by: Anand Gadiyar <gadiyar at ti.com>
Signed-off-by: Paul Walmsley <paul at pwsan.com>
---
 arch/arm/mach-omap2/clock3xxx_data.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/arch/arm/mach-omap2/clock3xxx_data.c b/arch/arm/mach-omap2/clock3xxx_data.c
index 41b155a..c226798 100644
--- a/arch/arm/mach-omap2/clock3xxx_data.c
+++ b/arch/arm/mach-omap2/clock3xxx_data.c
@@ -1408,7 +1408,7 @@ static struct clk ts_fck = {
 
 static struct clk usbtll_fck = {
 	.name		= "usbtll_fck",
-	.ops		= &clkops_omap2_dflt,
+	.ops		= &clkops_omap2_dflt_wait,
 	.parent		= &dpll5_m2_ck,
 	.enable_reg	= OMAP_CM_REGADDR(CORE_MOD, OMAP3430ES2_CM_FCLKEN3),
 	.enable_bit	= OMAP3430ES2_EN_USBTLL_SHIFT,





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