Hi Stefan R, On Thu, Sep 1, 2022 at 7:35 AM Simon Glass <s...@chromium.org> wrote: > > Hi, > > On Thu, 1 Sept 2022 at 03:27, Stefan Roese <s...@denx.de> wrote: > > > > Hi Tony, > > > > On 01.09.22 09:39, Tony Dinh wrote: > > > > <snip> > > > > >>> Some ideas. > > >>> > > >>> The get_timer() function looks wrong assigning an uint64_t to ulong. > > >>> > > >>> lib/time.c > > >>> > > >>> static uint64_t notrace tick_to_time(uint64_t tick) > > >>> uint64_t notrace get_ticks(void) > > >>> uint64_t __weak notrace get_ticks(void) > > >>> > > >>> ulong __weak get_timer(ulong base) > > >>> { > > >>> return tick_to_time(get_ticks()) - base; > > >>> } > > >>> > > >>> Most of the timer infrastructure is using uint64_t. I'm seeing this > > >>> __weak function get_timer was invoked in Kirkwood boards. Both in > > >>> sleep and timer commands. > > >> > > >> The get_ticks() thing can run at 1MHz but the timer is 1KHz, so that > > >> is why we don't need a u64 for the timer. > > This is wrong, I meant that get_tbclk() can run at 1MHZ (for example). > The tick is 1KHz. > > > > > > > Thanks for your explanation! However, would you agree that code is > > > problematic and needed some improvement ? IOW, depending what the > > > compiler does, it might return the 1st 32 bit of the 64-bit integer > > > result? > > Yes, we should really use ulong for the tick count as well. The use of > 64-bits seems wrong (on 32-bit machines). > > > > > It will return the lower 32 bits if the system is 32bit, yes. > > > > To check if we have a problem here, please add this (totally untested) > > code and extend it if it makes sense: > > > > diff --git a/lib/time.c b/lib/time.c > > index bbf191f67323..ef5252419f3b 100644 > > --- a/lib/time.c > > +++ b/lib/time.c > > @@ -146,7 +146,15 @@ int __weak timer_init(void) > > /* Returns time in milliseconds */ > > ulong __weak get_timer(ulong base) > > { > > - return tick_to_time(get_ticks()) - base; > > + u64 ticks = get_ticks(); > > + u64 time_ms = tick_to_time(ticks); > > + > > + if (time_ms & 0xffffffff00000000ULL) > > + printf("ticks=%lld time_ms=%lld\n", ticks, time_ms); > > + if ((time_ms - base) & 0xffffffff80000000ULL) > > + printf("ticks=%lld time_ms=%lld base=%ld ret=%lld\n", > > ticks, time_ms, base, time_ms - base); > > + > > + return time_ms - base; > > }
With this patch, indeed it showed a wrap around. And the system was frozen during the next command. Below is the log (my annotated comment starts with ***). <BEGIN LOG> U-Boot 2022.10-rc3-00048-g66ccd87a9c-dirty (Sep 01 2022 - 15:44:22 -0700) Pogoplug V4 SoC: Kirkwood 88F6281_A1 Model: Cloud Engines PogoPlug Series 4 DRAM: 128 MiB orion_timer_probe Clock Rate 166000000 orion_timer_probe successful Core: 19 devices, 15 uclasses, devicetree: separate NAND: 128 MiB MMC: mvsdio@90000: 0 Loading Environment from NAND... OK In: serial Out: serial Err: serial pcie0.0: Link up Net: eth0: ethernet-controller@72000 Hit any key to stop autoboot: 0 Pogo_V4> sleep 5 do_sleep got a timer start = 14344 do_sleep delay = 5000 do_sleep delay = 5000 do_sleep sleeping... do_sleep start 14344 curent 100 do_sleep start 14344 curent 200 <snip> do_sleep start 14344 curent 4800 do_sleep start 14344 curent 4900 do_sleep end of sleep ... current = 5000 Pogo_V4> sleep 10 do_sleep got a timer start = 22370 do_sleep delay = 10000 do_sleep delay = 10000 do_sleep sleeping... do_sleep start 22370 curent 100 do_sleep start 22370 curent 200 do_sleep start 22370 curent 300 do_sleep start 22370 curent 400 <snip> do_sleep start 22370 curent 3300 do_sleep start 22370 curent 3400 do_sleep start 22370 curent 3500 ticks=188 time_ms=0 base=22370 ret=-22370 do_sleep end of sleep ... current = 4294944926 *** we are seeing wrap around here Pogo_V4> sleep 15 do_sleep got a timer start = 15733 do_sleep delay = 15000 do_sleep delay = 15000 do_sleep sleeping... do_sleep start 15733 curent 100 do_sleep start 15733 curent 200 do_sleep start 15733 curent 300 do_sleep start 15733 curent 400 <snip> do_sleep start 15733 curent 9900 do_sleep start 15733 curent 10000 do_sleep start 15733 curent 10100 *** And the system was frozen here <END LOG> Thanks, Tony > > > > At least here, you seem to have a wrap around with the 32bits AFAICT: > > > > > GoFlexHome> sleep 20.5 > > > do_sleep got a timer start = 15031 > > > do_sleep delay = 20000 > > > do_sleep delay = 20500 > > > do_sleep sleeping... > > > do_sleep start 15031 current 100 > > > <snip> > > > do_sleep start 15031 current 6400 > > > do_sleep end of sleep ... current = 4294952265 > > > > > > *** Something strange happened here. current should be 6500, but it > > > seems to have garbage. So the loop exits prematurely. > > > > 4294952265 = 0xFFFFC549! > > Yes this all needs a look, I think. > > Regards, > Simon