Hi Mark,
On 2/10/19 6:44 PM, Mark Cave-Ayland wrote:
> In order to handle a race condition in MacOS 9, a delay was introduced when
> raising the VIA SR interrupt inspired by similar code in MacOnLinux.
>
> During original testing of the MacOS 9 patches it was found that the 30us
> delay used in MacOnLinux did not work reliably within QEMU, and a value of
> 300us was required to function correctly.
>
> Recent experiments have shown that the previous reliability issues are no
> longer present, and this value can be reduced down to 20us with no apparent
> ill effects in my local tests. This has the benefit of considerably improving
> the responsiveness of the ADB keyboard and mouse with the guest.
>
> Signed-off-by: Mark Cave-Ayland <mark.cave-ayl...@ilande.co.uk>
> ---
> hw/misc/macio/cuda.c | 11 +----------
> 1 file changed, 1 insertion(+), 10 deletions(-)
>
> diff --git a/hw/misc/macio/cuda.c b/hw/misc/macio/cuda.c
> index c4f7a2f39b..3febacdd1e 100644
> --- a/hw/misc/macio/cuda.c
> +++ b/hw/misc/macio/cuda.c
> @@ -97,17 +97,8 @@ static void cuda_set_sr_int(void *opaque)
>
> static void cuda_delay_set_sr_int(CUDAState *s)
> {
> - MOS6522CUDAState *mcs = &s->mos6522_cuda;
> - MOS6522State *ms = MOS6522(mcs);
> - MOS6522DeviceClass *mdc = MOS6522_DEVICE_GET_CLASS(ms);
> int64_t expire;
>
> - if (ms->dirb == 0xff || s->sr_delay_ns == 0) {
> - /* Disabled or not in Mac OS, fire the IRQ directly */
> - mdc->set_sr_int(ms);
> - return;
> - }
The change of sr_delay_ns below is well explained, but I don't
understand why you remove the previous if().
> -
> trace_cuda_delay_set_sr_int();
>
> expire = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + s->sr_delay_ns;
> @@ -542,7 +533,7 @@ static void cuda_realize(DeviceState *dev, Error **errp)
> s->tick_offset = (uint32_t)mktimegm(&tm) + RTC_OFFSET;
>
> s->sr_delay_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, cuda_set_sr_int, s);
> - s->sr_delay_ns = 300 * SCALE_US;
> + s->sr_delay_ns = 20 * SCALE_US;
>
> s->adb_poll_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, cuda_adb_poll, s);
> s->adb_poll_mask = 0xffff;
>
