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authorStephen Warren <swarren@nvidia.com>2012-07-24 17:48:12 -0400
committerStephen Warren <swarren@nvidia.com>2012-09-06 13:47:19 -0400
commiteb70e1bdd8a633e058cfb6186d45d4c8bdbdf534 (patch)
tree9c59a67a6100ca90d94a202aeff0a7c7c48ee042 /arch/arm/mach-tegra/tegra2_clocks.c
parent37c241ed668bd2271760c8e1e4138d1aba4d0b79 (diff)
ARM: tegra: fix U16 divider range check
A U16 divider can divide a clock by 1..64K. However, the range-check in clk_div16_get_divider() limited the range to 1..256. Fix this. NVIDIA's downstream kernels already have the fixed range-check. In practice this is a problem on Whistler's I2C bus, which uses a bus clock rate of 100KHz (rather than the more common 400KHz on Tegra boards), which requires a HW module clock of 8*100KHz. The parent clock is 216MHz, leading to a desired divider of 270. Prior to conversion to the common clock framework, this range error was somehow ignored/irrelevant and caused no problems. However, the common clock framework evidently has more rigorous error-checking, so this failure causes the I2C bus to fail to operate correctly. Signed-off-by: Stephen Warren <swarren@nvidia.com>
Diffstat (limited to 'arch/arm/mach-tegra/tegra2_clocks.c')
-rw-r--r--arch/arm/mach-tegra/tegra2_clocks.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/arm/mach-tegra/tegra2_clocks.c b/arch/arm/mach-tegra/tegra2_clocks.c
index a703844b2061..83ccb85b9405 100644
--- a/arch/arm/mach-tegra/tegra2_clocks.c
+++ b/arch/arm/mach-tegra/tegra2_clocks.c
@@ -223,7 +223,7 @@ static int clk_div16_get_divider(unsigned long parent_rate, unsigned long rate)
223 if (divider_u16 - 1 < 0) 223 if (divider_u16 - 1 < 0)
224 return 0; 224 return 0;
225 225
226 if (divider_u16 - 1 > 255) 226 if (divider_u16 - 1 > 0xFFFF)
227 return -EINVAL; 227 return -EINVAL;
228 228
229 return divider_u16 - 1; 229 return divider_u16 - 1;