[PATCH] ARM: OMAP2+: clockdomain: disabling unused clks
From: Mike Turquette <hidden>
Date: 2012-11-08 23:31:56
Also in:
linux-omap
Subsystem:
arm port, omap clock framework support, omap2+ support, the rest · Maintainers:
Russell King, Paul Walmsley, Aaro Koskinen, Andreas Kemnade, Kevin Hilman, Roger Quadros, Tony Lindgren, Linus Torvalds
The OMAP port to the common clk framework[1] resulted in spurious WARNs while disable unused clocks. This is due to _clkdm_clk_hwmod_disable catching clkdm->usecount's with a value of zero. Even less desirable it would not allow the clkdm_clk_disable function pointer to get called due to an early return of -ERANGE. This patch adds a check for such a corner case by skipping the WARN and early return in the event that clkdm->usecount and clk->enable_usecount are both zero. Presumably this could only happen during the check for unused clocks at boot-time. [1] http://article.gmane.org/gmane.linux.ports.arm.omap/88824 Signed-off-by: Mike Turquette <redacted> --- arch/arm/mach-omap2/clockdomain.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-)
diff --git a/arch/arm/mach-omap2/clockdomain.c b/arch/arm/mach-omap2/clockdomain.c
index 64e5046..b0c0ce6 100644
--- a/arch/arm/mach-omap2/clockdomain.c
+++ b/arch/arm/mach-omap2/clockdomain.c@@ -947,16 +947,22 @@ static int _clkdm_clk_hwmod_enable(struct clockdomain *clkdm) return 0; } -static int _clkdm_clk_hwmod_disable(struct clockdomain *clkdm) +static int _clkdm_clk_hwmod_disable(struct clockdomain *clkdm, + struct clk *clk) { unsigned long flags; + int clk_enable_count = 1; if (!clkdm || !arch_clkdm || !arch_clkdm->clkdm_clk_disable) return -EINVAL; spin_lock_irqsave(&clkdm->lock, flags); - if (atomic_read(&clkdm->usecount) == 0) { + /* corner case: disabling unused clocks */ + if (clk) + clk_enable_count = __clk_get_enable_count(clk); + + if (atomic_read(&clkdm->usecount) == 0 && clk_enable_count) { spin_unlock_irqrestore(&clkdm->lock, flags); WARN_ON(1); /* underflow */ return -ERANGE;
@@ -1026,7 +1032,7 @@ int clkdm_clk_disable(struct clockdomain *clkdm, struct clk *clk) if (!clk) return -EINVAL; - return _clkdm_clk_hwmod_disable(clkdm); + return _clkdm_clk_hwmod_disable(clkdm, clk); } /**
@@ -1089,6 +1095,6 @@ int clkdm_hwmod_disable(struct clockdomain *clkdm, struct omap_hwmod *oh) if (!oh) return -EINVAL; - return _clkdm_clk_hwmod_disable(clkdm); + return _clkdm_clk_hwmod_disable(clkdm, NULL); }
--
1.7.9.5