Minkyu, Thanks for comments. Please find my reply below the comment.
>On 28/02/13 19:59, Akshay Saraswat wrote: >> The pwm_config function in the exynos pwm driver divides by its period >> period parameter. A function was calling pwm_config with a 0ns period and a >> 0ns duty cycle. That doesn't actually make any sense physically, and results >> in a divide by zero in the driver. This change changes the paremters to be a > >typo. >paremters -> parameter > >> 100000ns period and duty cycle. >> >> Test with command "sf probe 1:0; time sf read 40008000 0 1000". >> Try with different numbers of bytes and see that sane values are obtained >> Build and boot U-boot with this patch, backlight works properly. >> >> Signed-off-by: Gabe Black <[email protected]> >> Signed-off-by: Akshay Saraswat <[email protected]> >> Acked-by: Simon Glass <[email protected]> >> --- >> Changes since v1: >> - Added "Acked-by: Simon Glass". >> >> arch/arm/cpu/armv7/s5p-common/timer.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/arch/arm/cpu/armv7/s5p-common/timer.c >> b/arch/arm/cpu/armv7/s5p-common/timer.c >> index de61405..6a0fa58 100644 >> --- a/arch/arm/cpu/armv7/s5p-common/timer.c >> +++ b/arch/arm/cpu/armv7/s5p-common/timer.c >> @@ -58,7 +58,7 @@ int timer_init(void) >> { >> /* PWM Timer 4 */ >> pwm_init(4, MUX_DIV_4, 0); >> - pwm_config(4, 0, 0); >> + pwm_config(4, 100000, 100000); > >0 is a numerator. >I think.. it doesn't matter. In file pwm.c line 98 we are doing: frequency = NS_IN_SEC / period_ns; what we are passing in this call are the values of duty_ns and period_ns. So, there are places where divide by zero may occur. I think we should keep it to be on a safer side. > >> pwm_enable(4); >> >> /* Use this as the current monotonic time in us */ >> > >Thanks, >Minkyu Kang. > Regards, Akshay Saraswat _______________________________________________ U-Boot mailing list [email protected] http://lists.denx.de/mailman/listinfo/u-boot
