| Message ID | 920eddc0e99bf57e7ac540502f863f222c401d2f.1629799776.git.fthain@linux-m68k.org |
|---|---|
| State | New |
| Headers | show |
| Series | [RFC,01/10] hw/mos6522: Remove get_load_time() methods and functions | expand |
On 24/08/2021 11:09, Finn Thain wrote: > Reads and writes to the TL and TC registers have no immediate effect on > a running timer, with the exception of a write to TCH. Hence these > mos6522_timer_update() calls are not needed. > > Signed-off-by: Finn Thain <fthain@linux-m68k.org> Perhaps better to flip this description around i.e. mention that the low bytes are written to a latch and then the full 16-bit value is transferred to the latch/counter when the high byte is written? Otherwise I think this looks okay. > --- > hw/misc/mos6522.c | 7 ------- > 1 file changed, 7 deletions(-) > > diff --git a/hw/misc/mos6522.c b/hw/misc/mos6522.c > index ff246b5437..1d4a56077e 100644 > --- a/hw/misc/mos6522.c > +++ b/hw/misc/mos6522.c > @@ -234,7 +234,6 @@ uint64_t mos6522_read(void *opaque, hwaddr addr, unsigned size) > val = s->timers[0].latch & 0xff; > break; > case VIA_REG_T1LH: > - /* XXX: check this */ > val = (s->timers[0].latch >> 8) & 0xff; > break; > case VIA_REG_T2CL: > @@ -303,8 +302,6 @@ void mos6522_write(void *opaque, hwaddr addr, uint64_t val, unsigned size) > break; > case VIA_REG_T1CL: > s->timers[0].latch = (s->timers[0].latch & 0xff00) | val; > - mos6522_timer1_update(s, &s->timers[0], > - qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL)); > break; > case VIA_REG_T1CH: > s->timers[0].latch = (s->timers[0].latch & 0xff) | (val << 8); > @@ -313,14 +310,10 @@ void mos6522_write(void *opaque, hwaddr addr, uint64_t val, unsigned size) > break; > case VIA_REG_T1LL: > s->timers[0].latch = (s->timers[0].latch & 0xff00) | val; > - mos6522_timer1_update(s, &s->timers[0], > - qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL)); > break; > case VIA_REG_T1LH: > s->timers[0].latch = (s->timers[0].latch & 0xff) | (val << 8); > s->ifr &= ~T1_INT; > - mos6522_timer1_update(s, &s->timers[0], > - qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL)); > break; > case VIA_REG_T2CL: > s->timers[1].latch = (s->timers[1].latch & 0xff00) | val; > ATB, Mark.
diff --git a/hw/misc/mos6522.c b/hw/misc/mos6522.c index ff246b5437..1d4a56077e 100644 --- a/hw/misc/mos6522.c +++ b/hw/misc/mos6522.c @@ -234,7 +234,6 @@ uint64_t mos6522_read(void *opaque, hwaddr addr, unsigned size) val = s->timers[0].latch & 0xff; break; case VIA_REG_T1LH: - /* XXX: check this */ val = (s->timers[0].latch >> 8) & 0xff; break; case VIA_REG_T2CL: @@ -303,8 +302,6 @@ void mos6522_write(void *opaque, hwaddr addr, uint64_t val, unsigned size) break; case VIA_REG_T1CL: s->timers[0].latch = (s->timers[0].latch & 0xff00) | val; - mos6522_timer1_update(s, &s->timers[0], - qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL)); break; case VIA_REG_T1CH: s->timers[0].latch = (s->timers[0].latch & 0xff) | (val << 8); @@ -313,14 +310,10 @@ void mos6522_write(void *opaque, hwaddr addr, uint64_t val, unsigned size) break; case VIA_REG_T1LL: s->timers[0].latch = (s->timers[0].latch & 0xff00) | val; - mos6522_timer1_update(s, &s->timers[0], - qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL)); break; case VIA_REG_T1LH: s->timers[0].latch = (s->timers[0].latch & 0xff) | (val << 8); s->ifr &= ~T1_INT; - mos6522_timer1_update(s, &s->timers[0], - qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL)); break; case VIA_REG_T2CL: s->timers[1].latch = (s->timers[1].latch & 0xff00) | val;
Reads and writes to the TL and TC registers have no immediate effect on a running timer, with the exception of a write to TCH. Hence these mos6522_timer_update() calls are not needed. Signed-off-by: Finn Thain <fthain@linux-m68k.org> --- hw/misc/mos6522.c | 7 ------- 1 file changed, 7 deletions(-)