| Message ID | AANLkTinY9UIE1l-f1V7l7vDCH77pStpmF-lZeyJKtF-J@mail.gmail.com |
|---|---|
| State | New |
| Headers | show |
On Sat, Jul 3, 2010 at 1:34 PM, Artyom Tarasenko <atar4qemu@googlemail.com> wrote: > 2010/5/30 Blue Swirl <blauwirbel@gmail.com>: >> On Sat, May 29, 2010 at 9:33 PM, Artyom Tarasenko >> <atar4qemu@googlemail.com> wrote: >>> For me is also interesting what do we miss in the microSPARC implementation. >>> If I switch off POST (which crashes due to the known FPU problems) >>> LX/CX/X OBPs hang. Looks like it's expecting some interrupt (the SS-5 >>> OBP escapes a similar endless loop on a timer irq), but not getting >>> it. >>> Do you know anything obvious qemu is missing in LX machine? >> >> I don't have a device tree for LX, but unimplemented interrupt sources >> could be audio, parallel port, video, modem. Floppy may be buggy. > > Nice try. :) But it was really waiting for the timer irq. The > following patch solves the problem, but I'm not sure if it's the > proper place for the fix. > > --- a/hw/slavio_timer.c > +++ b/hw/slavio_timer.c > @@ -232,6 +231,12 @@ static void slavio_timer_mem_writel(void *opaque, > target_phys_addr_t addr, > } else { > ptimer_set_limit(t->timer, LIMIT_TO_PERIODS(t->limit), 1); > } > + if (t->running) { > + ptimer_stop(t->timer); > + ptimer_run(t->timer, 0); > + > + } > + > } > } > break; > > The interrupt is not generated if the timer has been running at the > time ptimer_set_limit() is called. Not sure what is the > ptimer_set_limit()'s contract. Should it handle changing the limit on > a working timer? I think it does. In fact, the only difference that ptimer_stop()/ptimer_run() sequence adds to the previous ptimer_set_limit() is that s->delta is calculated with ptimer_get_count() instead of the limit being set. I wonder if the 96/64 bit division in ptimer_get_count() is correct or if ptimer_set_limit() should do something differently. > > The patch makes LX OBP v2.10 sort of functional (it fails on DBRI and > cg6 init, but gets up to the "ok" prompt), and SS-10 OBP v2.10 fully > functional (with some cpu models). > > The later is interesting: it autodetects SX/cg14, so can work with the > Bob's cg14 patch, as well as without it. Great!
--- a/hw/slavio_timer.c +++ b/hw/slavio_timer.c @@ -232,6 +231,12 @@ static void slavio_timer_mem_writel(void *opaque, target_phys_addr_t addr, } else { ptimer_set_limit(t->timer, LIMIT_TO_PERIODS(t->limit), 1); } + if (t->running) { + ptimer_stop(t->timer); + ptimer_run(t->timer, 0); + + } + } }