There's no reason to set an arbitrary upper bound of 10 seconds. We can simply set the comparator such that it'll take a whole cycle through all 32-bit values until the next interrupt would be raised. (For an extremely fast-running HPET [400 MHz and up] 10 seconds would also be too long.)
Signed-off-by: Jan Beulich <[email protected]> --- v4: New. --- a/xen/arch/x86/hpet.c +++ b/xen/arch/x86/hpet.c @@ -23,7 +23,6 @@ #include <asm/irq-vectors.h> #include <asm/msi.h> -#define MAX_DELTA_NS MILLISECS(10*1000) #define MIN_DELTA_NS MICROSECS(20) #define HPET_EVT_USED_BIT 0 @@ -162,10 +161,15 @@ static int reprogram_hpet_evt_channel( ch->next_event = expire; - delta = min_t(int64_t, delta, MAX_DELTA_NS); delta = max_t(int64_t, delta, MIN_DELTA_NS); delta = ns2ticks(delta, ch->shift, ch->mult); + if ( delta > UINT32_MAX ) + { + hpet_write32(hpet_read32(HPET_COUNTER), HPET_Tn_CMP(ch->idx)); + return 0; + } + do { ret = hpet_next_event(delta, ch->idx); delta += delta;
