diff options
| author | Nagesh Penumarty <vpenumarty@nvidia.com> | 2010-01-12 16:19:41 +0530 |
|---|---|---|
| committer | Nagesh Penumarty <vpenumarty@nvidia.com> | 2010-01-13 10:59:58 +0530 |
| commit | 8930c80f0ece9edf667f7ad593e15233367cb1dc (patch) | |
| tree | 3b5215242e4a56ba2d8f13338fdedabbe8fa921f /arch/arm/mach-tegra/nvrm | |
| parent | 075c532f2940f504549b85f308ee140d80cb1e13 (diff) | |
tegra RM: Fix PWM scaling calculation in RM for backlight intensity.
Fixed PWM scaling calculation and added boundary check. This is an 8-bit
value that was being scaled to a max of 256 instead of 255, causing an
overflow in the boundary case of a maximum setting (thereby resulting in 0).
Bug 638387 [Harmony] Backlight is broken and there is no display.
Bug 627575 [firefly2/Harmony/Display]External display panel not adjusting
to Brightness change from display settings.
Tested on: Android, Harmony
Diffstat (limited to 'arch/arm/mach-tegra/nvrm')
| -rw-r--r-- | arch/arm/mach-tegra/nvrm/io/ap15/ap15rm_pwm.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/arch/arm/mach-tegra/nvrm/io/ap15/ap15rm_pwm.c b/arch/arm/mach-tegra/nvrm/io/ap15/ap15rm_pwm.c index dbaf41563bd4..14c58e4e28f3 100644 --- a/arch/arm/mach-tegra/nvrm/io/ap15/ap15rm_pwm.c +++ b/arch/arm/mach-tegra/nvrm/io/ap15/ap15rm_pwm.c @@ -316,7 +316,7 @@ void NvRmPwmClose(NvRmPwmHandle hPwm) NvOsMutexUnlock(s_hPwmMutex); } -#define MAX_DUTY_CYCLE 256 +#define MAX_DUTY_CYCLE 255 NvError NvRmPwmConfig( NvRmPwmHandle hPwm, @@ -416,7 +416,9 @@ NvError NvRmPwmConfig( * Convert from percentage unsigned 15.16 fixed point * format to actual register value */ - DCycle = (NvU8)((DutyCycle * MAX_DUTY_CYCLE/100)>>16); + DCycle = (DutyCycle * MAX_DUTY_CYCLE/100)>>16; + if (DCycle > MAX_DUTY_CYCLE) + DCycle = MAX_DUTY_CYCLE; RegValue = PWM_SETNUM(CSR_0, ENB, PwmMode) | PWM_SETNUM(CSR_0, PWM_0, DCycle); |